지역에너지시스템의 안정적인 계통 연계 및 독립운전 방법에 대한 연구

홍성민 강원대학교 2009 국내석사

This paper research a stabile operating method when the Community Energy System (CES) is operated islanding mode. The basic concept of CES is that it supplies electrical and thermal energy to the local cusomer loads through the islanded power network separated from the grid. The CES must be supplying local load with stabile energy on the islanding mode, analysing to CES islanding operation. In order to show them, in this paper, we model the CES with two synchronous generators of 2.0MVA(SMART:System-Integrated Modular Advance Reactor) and interfaced DC/AC generator of 2MVA and simulate the operating feature on the island mode of CES. Also this paper make a criteria of CES stabile operation with Grid connected and island mode. The simulation result show that, the CES operate the efficient load management and generation control during the transition periods, using the suggestion of CES stabile operation criteria. 본 논문에서는 과도 현상 해석 프로그램인 PSCAD/EMTDC(Power System ComputerAided Design/Electro MagneticTransientsin DC systems)를 이용하여 지역 에너지 시스템에 대한 계통 영향 분석 및 단독 운전 시 부하 특성에 따른 발전기 운전 특성을 분석하여 각 시나리오 상황에 따른 지역 에너지 시스템 운전방법을 도출해 내었다. 이의 연구를 위해서 22.9kV 배전 계통과 임의로 선정한 6.6kV 배전 계통에 동기발전기와 계통 연계형 인버터 발전기를 연계하여 proto-type의 지역 에너지 시스템 연계 배전 계통을 구성해 보았다. 모델링 테이터는 모두 실 데이터를 이용하였으며, 운전 특성 및 시나리오 설정 시에도 실제와 같은 조건으로 모의를 하였다. 지역 에너지 시스템에 새로 설치한 내부 발전기(일체형 원자로, 계통 연계형 인버터)를 투입할 때에는 내부 연계 지점과의 전압, 주파수, 위상을 동기 투입 조건하에 두고 먼저 투입된 발전기가 안정화되어 후에 투입되는 발전기가 영향을 받지 않도록 해야한다. 지역 에너지 시스템이 독립 운전으로 전환후에는 부하 증가가 CES 운영자가 규정한 단위 시간당 출력을 넘는다면 이를 감지하고 배전 계통과 연계시에는 내부 연계지점과 배전 계통의 전압, 주파수, 위상의 차이를 적게하며 절체시에는 내부 연계지점의 전압의 하강이 기준을 넘지 않을 때 시행하여야한다. 또한 내부 계통 사고시 내부 발전기가 사고에 버티는 정도를 분석하여 내부 발전기 사고시 부하 절체 시간 설정 및 배전 선로 사고 시 재폐로기 시간 설정을 해주어야 한다. 연계 운전 중 내부 발전기 용량과 부하 용량의 차이에 따른 지역 에너지 시스템의 독립 운전 전환 시 내부 보호 장치의 동작 시간을 고려하여 부하 절체 및 내부 발전기 절체가 이루어져야 한다. 이러한 운영 방법은 일체형 원자로가 연계된 지역 에너지 시스템을 안정적으로 운전할 수 있게 한다.

토마토 식초의 항산화 효과

홍성민 순천대학교 대학원 2012 국내석사

To solve surplus tomatoes and enhance the utility value effectively, this study was developed a tomato vinegar by two stages fermentation. Physiochemical component of the tomato vinegar was analyzed and their antioxidant activities were examined in vitro such as hydrogen donating activity, ABTS.+ radical scavenging activity, hydroxyl radical scavenging activity and β-carotene bleaching assay. In the alcohol fermentation process, tomato wine was manufactured from the juice at 30℃ for 4 days. In the acetic acid fermentation process, tomato vinegar was conducted at 30℃, 200 rpm for 8 days. As a result, the tomato vinegar of total acidity was 5.6%. In the analysis result, tomato vinegar was found out that it contains many kinds of free sugar, organic acid, free amino acid and mineral. It was also shown that the content of acetic acid was the most abundant organic acid followed by lactic acid, citric acid and malic acid. The major amino acids of tomato vinegar were lysine, valine, phenylalanine, arginine. As for mineral content, potassium and phosphorus were higher whereas manganese and copper were extremely low. The lycopene, total carotenoid and total polyphenol contents of tomato vinegar were 3.19, 6.45 and 37.10 mg/100 mL respectively. Hydrogen donating activity of tomato vinegar was 63%. however, it has not strong effect as other putative antioxidants such as 0.1% BHT and 0.1% α-tocopherol. Also, another effective method to measure radical scavenging activity is the ABTS.+ radical scavenging assay, which showed similar results to those obtained in the hydrogen donating activity. Hydroxyl radical scavenging activity and SOD-like activity was approximately 65% and 61%. Hydrogen peroxide scavenging activity of tomato vinegar was 251.30 μg/mL, which showed similar results to 0.1% BHT. β-Carotene bleaching also were higher in the tomato vinegar than in those of the crushed tomato, tomato initial broth and tomato wine. Therefore, these results indicated that tomato vinegar may be used as functional food material which has antioxidant activity.

항공 기체 구조 변경을 위한 진동 및 구조해석

홍성민 충남대학교 산업대학원 2021 국내석사

In this paper, the structural change due to the addition of new equipment to the aircraft body was analyzed. The vibration conditions of the aircraft were calculated based on the MIL-STD-810G specification, considering the aircraft power type, structure, and engine speed, and a vibration test was performed, and the operating vibration conditions were calculated considering the measurement results. The requirements for verifying the stability of the structural FEM were confirmed by the margin (M.S) related to stiffness and strength. Load conditions were created for margin analysis, and structural stability was verified for external attachments of aircraft by performing static analysis related to structural strength analysis using MSC/Patran and Nastran. Modal analysis was performed with the model, and the technical value described in the vibration test did not appear in the model, thus expanding the range of structural analysis. As the range was expanded, the structural strength analysis was conducted again, and after confirming the safety margin, vibration analysis was conducted again to compare and analyze the values from the test. The structural vibration test result due to the structural change of the aircraft and the natural frequency obtained as the Modal of the structural FEM model show similar values between the test data and the FEM result.

남자 중학생의 자유학기제 체육활동에 따른 진로성숙도와 친밀감의 관계

홍성민 경남대학교 2018 국내석사

The purpose of this study is to investigate the relation between male middle school students’ course maturity and intimacy according to physical education in free-semester system. It is based on a survey of 299 male middle school students in C-si, Gyeongsangnamdo Korea; 151 who participated in P.E. in free-semester system and 148 who didn’t take the class. The survey, which was conducted after physical activities of free-semester system, was processed by SPSS/PC Window V21.0 so that we can analyze the information to serve the purpose of this study. The following is the conclusion drawn by the survey. First, there were gaps in course maturity according to the academic performance, which is the demographic characteristic of male middle school students. Depending on academic performance, there was a significant difference in all of the components of course maturity; knowledge of a desired job, rational decision making, planning quality, self-understanding, independence, attitudes towards job, and information search. In terms of parents’ educational background, there was a distinct difference in knowledge of a desired job, rational decision making, planning quality, and attitudes towards job. According to demographic gaps in intimacy, there was a statistically significant difference in the following components; comfort, trust, self-disclosure, and communication depending on academic performance. However, there was no significant difference in all of the components of the intimacy in regard to parents’ educational background. Second, as for the difference of course maturity and intimacy depending on the participation in physical activities under free-semester system, there were gaps in both. In respect of course maturity, there was a statistically significant difference in knowledge of a desired job, planning quality and self-understanding. In terms of intimacy, there was a significant difference in self-disclosure and communication. Third, with reference to the effect of male middle school students’ course maturity resulted from the participation in physical education under free-semester system on intimacy, all the factors except for plan quality, information search, sympathy, self-knowledge, communication, and trust have positive relationship. Fourth, with reference to the effect of male middle school students’ course maturity resulted from the participation in physical education under free-semester system on intimacy, knowledge of a desired job which is a subordinate factor to course maturity have an influence on comfort which is a subordinate factor to intimacy. Rational decision making has an impact on comfort, trust, sympathy and sincerity. Plan quality has an effect on comfort, trust, self-disclosure, and sympathy. Independence influences on comfort, self-disclosure. Attitudes towards job effects on comfort and sympathy. The follow-up study requires qualitative research method including depths interview, observation and interview targeting female students and students from different regional background. In addition, the follow-up study needs to examine different variables related to students' aptitude, course, self-improvement, building character and the satisfaction with school life following the trend of free-grade system, which is implemented in more schools. 본 연구는 중학교 남학생의 자유학기제 체육활동에 따른 진로성숙도와 친밀감의 관계를 알아보기 위해 경상남도 C시에 소재한 남자 중학교 1학년 학생 중 자유학기제 체육활동에 참여한 학생 151명과 미 참여 학생 148명, 총 299명을 대상으로 설문조사를 실시하였다. 자유학기제 체육활동에 참여한 후 설문지를 배포하였으며 회수한 설문지의 자료처리는 SPSS/PC Window V21.0 프로그램을 이용하여 연구목적에 맞게 분석하였으며, 얻어진 결론은 다음과 같다. 첫째, 남자 중학생들의 인구통계학적 특성인 학업성취도에 따른 진로성숙도의 차이에서는 하위요인인 희망직업에 대한 지식, 합리적 의사결정, 계획성, 자기이해, 독립성, 직업에 대한 태도, 정보탐색 모두 통계적으로 유의한 차이가 나타났고, 보호자의 최종학력에서는 희망직업에 대한 지식, 합리적 의사결정, 계획성, 직업에 대한 태도에서만 통계적으로 유의한 차이가 나타났다. 학업성취도에 따른 친밀감의 차이에서는 하위요인인 위안, 신뢰감, 자기노출, 진심, 의사소통에서 통계적으로 유의한 차이가 나타났고, 보호자의 최종학력에서는 친밀감의 모든 하위요인에서 통계적으로 유의한 차이가 나타나지 않았다. 둘째, 남자 중학생들의 자유학기제 체육활동 참여에 따른 진로성숙도는 하위요인 중에서 희망직업에 대한 지식, 계획성, 자기이해에서만 통계적으로 유의한 차이가 나타났고, 친밀감에서는 하위요인인 자기노출, 의사소통에서만 통계적으로 유의한 차이가 나타났다. 셋째, 남자 중학생의 자유학기제 체육활동 참여에 따른 진로성숙도와 친밀감의 상관관계 분석에서는 계획성과 정보탐색, 계획성과 공감, 자기이해와 의사소통, 의사소통과 신뢰감, 의사소통과 공감을 제외한 모든 요인에서 정(+)적인 상관관계가 있는 것으로 나타났다. 넷째, 남자 중학생의 자유학기제 체육활동 참여에 따른 진로성숙도가 친밀감에 미치는 영향을 분석한 결과, 진로성숙도의 하위요인인 희망직업에 대한 지식, 합리적 의사결정, 계획성, 독립성, 직업에 대한 태도가 친밀감의 하위요인이 위안에, 합리적 의사결정, 계획성이 신뢰감에, 계획성, 독립성은 자기노출에, 합리적 의사결정, 계획성, 직업에 대한 태도는 공감에, 희망직업에 대한 지식(t=.435, p=.664), 합리적 의사결정은 진심에 영향을 미치는 것으로 나타났다. 향후 자유학기제에 대한 다양한 성별과 지역의 학생을 대상으로 심층면접, 관찰, 인터뷰와 같은 질적 연구와 같은 후속 연구가 필요하다고 생각되며, 앞으로 자유학기제에서 자유학년제로 확장되어 가는 추세에 맞추어 학생들의 적성과 진로, 자기계발과 인성함양, 학교생활 만족과 관련된 다양한 변인들의 연구가 지속적으로 이루어져야 한다고 생각된다.

지역총생산과 지방재정지출의 상호관계에 대한 연구 : 케인지안 이론과 바그너 법칙

홍성민 단국대학교 대학원 2017 국내석사

This paper investigates the correlation between Gross Regional Domestic Product(GRDP) and Local government expenditure(LGE). LGE has dramatically increased and I intend to analyze economic effect of local government expenditure after the local autonomy system in 1991. So I set two hypothesis - one is the Keynesian theorem that LGE affects GRDP and another is the Wagner`s law that GRDP affects LGE - so that I look into better fitted economical model in case of Korea throughout 15 provinces & cities for 25 years (1989-2013). I used panel VAR because two variables have no cointegration in Westerlund panel cointegration test. As a result of this empirical study, it shows that the Wagner`s law is suitable for Korean regional economy. This result has lots of contributions, first, I could not find any cointegration because Korean economy has largely changed in 1997 IMF a foreign-exchange and 2008 financial crisis. Second, I used longest and updated time series data. After that, I revealed the estimation methods of Difference and System GMM. But I have still some problems that because of short time series, I did not see analysis results of the individual group. And I could not track expenditure in one area. But it will be fine by using the total data after several years. 본 연구는 지역총생산과 지방재정지출 간의 상호관계에 대한 분석이다. 1991년 지방자치제 실시 후 지방재정지출의 급격한 증가와 경제적 승수효과에 대해 사람들의 관심이 증대되고 있는 바, 이에 지방재정지출과 지역경제성장에 대한 관계를 케인지안 이론과 바그너 법칙 두 가지 가설을 세워 분석하였다. 지출이 성장을 견인한다는 전통적인 케인지안 승수이론과 지출은 단지 성장의 결과라는 바그너 법칙 중 우리나라 경제에 더 적합한 것이 무엇인지 규명하는 것을 목적으로 연구를 시작하였다. 연구의 분석기간은 1989년부터 2013년까지이고 분석지역은 15개 특별·광역시 및 도지역이다. 지역총생산(GRDP)과 지방재정지출 자료를 결합하여 패널자료를 구축한 뒤 패널 공적분 검정(panel cointegration test)을 실시하였고, 공적분 관계가 존재하지 않는다는 검정결과에 따라 패널 VAR(Vector Autoregressive) 모형으로 분석하였다. 본 연구는 실증분석 결과에 따라 다음과 같이 몇 가지 결론을 얻을 수 있었다. 우리나라는 지역총생산이 지방재정지출에 더 많은 충격을 주는 것으로 바그너 법칙을 입증할 수 있었다. 또한 공적분 관계가 도출되지 않았고, 최장·최신의 시계열을 사용하여 명확한 추정방법을 제시함에 따라 보다 모형의 강건성(robustness)을 확보할 수 있었다. 다만 시계열이 짧아 개별지역 분석을 할 수 없다는 점, 한 지역 내의 지출이 반드시 그 지역에서만 이루어지지 않는다는 점 등이 풀리지 못한 채 여전히 한계점으로 남아 있다. 하지만 추후 연구에서 미래의 시계열 자료를 더 확보하거나 총량지표를 사용하여 실증분석을 한다면 이 문제에 대해 어느 정도 해결책을 제시해 줄 수 있을 것으로 보인다.

EVALUATION OF PLANT PROTEIN SOURCE SUPPLEMENTATION ON NUTRIENT AVAILABILITY AND PERFORMANCE IN SWINE DIET

홍성민 단국대학교 대학원 2013 국내박사

This study was conducted to evaluate the effect of Kapok seed meal supplementation on growth performance, nutrient digestibility, blood profiles, fat characteristic and meat quality in finishing pigs. A total of 96 finishing pigs (Landrace × Yorkshire × Duroc) with an average initial BW of 67.02 ± 1.46 kg were used in a 10 week trial. Pigs were randomly allotted to three dietary treatments with eight replicates per treatment and four pigs per pen (two barrows and two gilts). The dietary treatments were: 1) CON, basal diet; 2) K1.5, basal diet + 1.5% kapok; 3), K3.0, basal diet +3.0%. The results showed that supplementation with Kapok seeds reduced nutrient digestibility of dry matter, nitrogen and energy (P<0.05), yet didn’t affect growth performance (P>0.05) and Kapok seeds diet could elevate the concentration of LDL (low density lipoprotein) in blood at the 10th wk of experimental phase (P<0.05). Moreover, supplementation with 3% kapok seed increased the redness and yellowness of meat (P<0.05). Kapok seeds meal also significantly elevated the content of C18:0, C14:0 and total short fatty acid (P<0.05), decreased the content C18:1 and the ratio of C18:0/C18:1 and decreased the content of C16:0 in porcine fats (P<0.05). Similarly, supplementation with Kapok seed increased the content of C18:0 (P<0.05), besides decreased the content of C18:1 and C16:1 of the fatty acid of muscle (P<0.05). These results indicated that swine diet supplemented with 3% kapok seed can affect meat quality and enhance the content of fatty acids of carcass fats and muscle without the effect of growth performance. This study was conducted to evaluate the apparent total tract and ileal nutrient digestibility in SBM, rapeseed meals from Korea and India and distillers dried grain with solubles (DDGS) in growing pigs. A total of 4 barrows with an average initial body weight (BW) of 23.37 ± 1.11 kg were fitted with a simple T-cannula, and were used in a 4×4 Latin square design. The pigs were fed on three corn starch-based diets contain SBM, and rapeseed meal from Korea and India. The pigs were fed two times daily, equal amounts at 08:00 and 20:00, at a rate of 5% (wt./wt.) of the BW0.9. The BW was determined at the initial of each experimental period. Each experimental period comprised 8 days. Faeces were collected from 08:00 on d 5 to 08:00 on d 6. Ileal digesta were collected for a total of 48h, from 08:00 on d 7 to 08:00 on d 8. 0.2% chromic oxide was used as a digestibility marker. The ATTD of DM and N, and AID of DM, N and GE of SBM treatment was the highest (P<0.05) among diets. Pigs fed the KRSM diet had higher (P<0.05) ATTD of N and GE, AID of N and GE than the pigs fed the IRSM diet. Moreover, the AID of N and GE of pigs fed the DDGS diet was higher (P<0.05) than that in IRSM treatment. The AID of isoleucine, leucine, lysine, methionine, phenylalanine, valine, threonine, and all analyzed non-essential amino acids of pigs fed SBM diet was higher (P<0.05) than pig fed the IRSM diet. The KRSM treatment had higher (P<0.05) AID of isoleucine, lysine, leucine, threonine, alanine, serine, tyrosine and total essential amino acids compared with the IRSM treatment. Moreover, the DDGS treatment had higher (P<0.05) AID of leucine, alanine and glutamic acid and lower (P<0.05) AID of glycine compared with the IRSM treatment. The N retention rate was not affected (P>0.05) by dietary treatments. In conclusion, the ATTD of N and GE, AID of GE and essential AA were improved by RSM from Korea compare with RSM from India. Moreover, the ATTD of N and energy were improved in RSM from Korea compare with DDGS A total of 16 sows with an average initial body weight (BW) kg of 258.87 ± 5.36 kg were used in this trial. This study was conducted to evaluate the blood profiles and nutrient digestibility of sows and piglets fed with RSM, CM and their mixture (RSCM) was conducted in our present study. The BW and backfat of sows was checked 4 days before farrowing and at the weanling day to calculate the body weight loss and the backfat loss during that period. Sows fed with RSM and RSCM diets had a greater (P<0.05) body weight loss during farrowing to weanling period compared with sows fed with CON diet. During the 1 wk, the piglets in CON treatment had a higher (P<0.05) ADG than in RSM treatment. The RSM treatment had a higher (P<0.05) fecal score compared with that of CON treatment on d 5, 7, 11, 12, 15 and 16, moreover, that in CM treatment was higher (P<0.05) than in CON treatment on d 12 and 14. The number of diarrhea piglets in RSM was higher (P<0.05) than in CON on d 7 and 15. After farrowing, the ATTD of DM in sows fed with CON diet was higher (P<0.05) compared with sows fed with RSCM diet. The ATTD of E in CON and CM treatments was higher (P<0.05) than in RSM and RSCM treatments. When on the weanling day, the ATTD of N and E in CON was highest (P<0.05). For blood profiles, there was no difference (P>0.05) observed among treatments in sows and piglets. In conclusion, supplementation of dietary rapeseed meal increased body weight loss of sow during farrowing to weanling, increased the diarrhea rate of piglets, decreased the ADG of piglet and the nutrient digestibility, moreover, it decreased the creatinine concentration and increased the glucose in blood. While, the mixture of rapeseed meal and CM increased the body weight loss of sow during farrowing to weanling, decreased the nutrient digestibility, decreased the glucose and increased the BUN concentration in blood profiles in sow. Two experiments were conducted to evaluate the apparent total tract and ileal nutrient digestibility in soybean meal (SBM), rapeseed meal (RSM) and canola meal (CM) for growing pigs and finishing pigs. In experiment (exp) 1, 3 growing barrows with average initial body weight (BW) of 22.68 ± 0.18 kg and in experiment 2, 3 finishing barrows with average initial BW of 49.43 ± 0.78 kg were fitted with simple T-cannulas, and were used in a 3×3 Latin square design. The pigs were fed on three cornstarch-based diets contain SBM, RSM and CM, respectively. The pigs were fed two times daily, equal amounts at 08:00 and 20:00, at a rate of 5% (wt./wt.) of the BW0.9. The BW was determined at the initial of each experimental period. Each experimental period comprised 8 days. Faeces were collected from 08:00 on d 5 to 08:00 on d 6. Ileal digesta were collected for a total of 48h, from 08:00 on d 7 to 08:00 on d 8. 0.2% chromic oxide was used as a digestibility marker. In exp 1, the apparent total tract digestibility (ATTD) and apparent ileal digestibility (AID) of DM and energy exhibited no difference (P>0.05) among diets. Pigs fed the SBM and CM diets had greater (P<0.05) ATTD of nitrogen (N) than pig fed the RSM diet. The AID of N of pig fed the CM diet was greater (P<0.05) than that in RSM treatment. The AID of lysine, threonine and valine of growing pigs fed SBM and CM diets was higher (P<0.05) than the RSM treatment. In exp 2, the AID of N of finishing pigs fed SBM and CM diets was higher (P<0.05) than that of RSM treatment. Moreover, the AID of histidine, methionine, and glutamic acid of pigs fed the SBM and CM diets was higher (P<0.05) than pigs fed the RSM diet. In conclusion, the ATTD and AID of N of growing pig and the AID of N of finishing pig fed with CM were improved (P<0.05) compared with RSM.

전방십자인대 손상 유무에 따른 알파인 스키 선수의 체간·하지 근 기능 및 균형능력 비교연구

홍성민 한국체육대학교 2019 국내석사

본 연구는 대학생 알파인 스키선수를 대상으로 전방십자인대 손상 집단 5명(Injury, n=5), 비손상 집단 6명(Non-Injury, n=6) 총 11명의 알파인 스키 선수 대상으로 체간과 하지의 근 기능과 균형능력을 비교하여 알파인 스키선수들의 부상예방에 대한 기초자료로 제시하고자 하였다. 체간의 근 기능으로 등속성 근력을 측정하고, 하지의 근 기능으로 슬관절의 등속성 근력, 등척성 근력을 측정하여 슬관절 신전근의 구심성 수축과 굽힘근의 신전성 수축을 통한 기능적 근력비를 평가하였고, 균형능력을 평가하기 위해 동적 균형능력으로 지지판 안정도 변화에 따른 균형능력과 정적 균형능력인 Y-Balance Test를 실시하였다. 전방십자인대 손상유무에 따른 알파인 스키선수의 체간, 하지 근기능 및 균형능력 차이를 검증하기 위해 Mann whitney U-Test를 실시하였으며, 이때 모든 통계의 유의 수준은 ⍺=.05로 설정하였다. 본 연구의 결과는 다음과 같다. 1. 체간 근 기능 검사에서 손상 집단에 비해 비손상 집단의 체간 굴곡·신전 근력이 높은 경향을 보였으나, 통계적으로 유의한 차이는 나타나지 않았다. 2. 하지 근 기능 검사로 기능적 근력비, 동측성 근력비율, 등척성 근력검사에서는 유의한 차이가 나타나지 않았으나, 각속도 180°/sec에서 최대우력 검사 신전 근력에서 유의한 차이가 나타났으며, 신전근의 근파워 또한 유의한 차이를 보였다(p<.05). 3. 균형능력 검사로 정적 균형능력 검사인 Y-Balance Test에서는 손상 집단에 비해 비손상 집단이 높은 점수를 나타냈으나, 통계적으로 유의한 차이는 나타나지 않았으며, 동적 균형능력 검사인 중력중심 조절 능력에서는 좌측과 전방좌측에서 유의한 차이가 나타났다(p<.05). 결과를 종합하여 볼 때, 전방십자인대 손상 유·무에 따라 슬관절 신전근의 근력과 동적 균형능력에 대한 차이를 확인하였으며, 이는 알파인스키 선수의 슬관절에 대한 주동근과 길항근에 대한 협응과 종목의 특성을 고려한 부상 예방 운동 프로그램 개발의 기초자료로 사용 할 수 있을 것으로 판단된다. In this study, total 11 alpine skiers were selected and divided into Injury Group(IG, n = 5) and Non-Injury Group(NIG, n = 6) to compare muscle function of the trunk and lower extremity and balance ability between alpine skiers with and without ACL injury. Trunk isokinetic muscle strength and knee isokinetic muscle strength was measured for muscle function of the trunk and lower extremity. And also isometric muscle strength, and functional muscle strength ratio were assessed by concentric contraction in the extensor muscles and flexor muscle eccentric contractions. Y-Balance Test was performed in order to evaluate the dynamic balance ability, and static balance ability according to the change of the support plate stability was performed. The Mann whitney U-Test was used to analyse the statistical difference in uscle function of the trunk and lower extremity and balance ability of the Alpine skiers with and without anterior cruciate ligament injury. The significance level of all statistics was set at ⍺ = .05. The results of this study are as follows. 1. In the trunk muscle function Test, the trunk flexion / extension muscle strength of the NIG was higher than that of the IG, but there was no significant difference statistically. 2. There was no significant difference in functional muscle strength ratio, ipsilateral muscle strength ratio, and isometric strength in leg muscle function Test, but there was a significant difference in peak torque extensor muscle at each speed of 180 ° / sec. There was also a significant difference in muscle power of extension muscle(p<.05). 3. The Y-Balance Test as a static balance Test showed a higher score in the NIG than in the IG, but no significant difference was found statistically. In the center of gravity control ability, which is a dynamic balance ability Test, there was a significant difference between left and anterior left(p<.05). These results showed that the difference in strength and dynamic balance ability of the knee extensor muscles with and without anterior cruciate ligament injuries was confirmed. It can be used as a basic data for the development of the injury prevention exercise program considering the coordination of the main muscle and the antagonist muscle of the knee joint of the Alpine skier and the characteristics of the event.

Fe계 자성분말-에폭시 복합재의 전자파 흡수특성

홍성민 忠南大學校 大學院 2009 국내박사

Recently, the use of wireless telecommunication systems and high-frequency circuit devices has increased dramatically. Electronic devices such as cellular phones and personal computers emit electromagnetic wave that cause serious electromagnetic interference phenomena and result in wave pollution problems. As the best method for preventing such phenomena, electromagnetic wave absorbers are generally used. The electromagnetic wave absorbers are defined as materials that can effectively attenuate the intensity of electromagnetic wave by magnetic or dielectric loss. Spinel ferrite-polymer composites are representative narrow-band absorbers for the several hundreds megahertz to several gigahertz frequency range and have been most widely used due to their adequate absorption efficiency (>20 dB) and easiness in theoretical design for practical applications. The major limitation to expanding the application of these ferrite-polymer composites lies in their thick thickness for obtaining high absorption efficiency caused by their low real parts of complex permeability and permittivity values. In order to overcome this problems, the development of new absorbers using magnetic amorphous alloy-polymer composites has been attempted. Although amorphous alloy-polymer composites have very high potentiality for thinner absorber, it is demanded to understand the relationship between materials constants and absorption properties for the development of thinner absorber. However, very few systematical reports have been made on the electromagnetic properties and electromagnetic wave absorption properties of the absorber using amorphous alloy composites. The purpose of this dissertation is to understand the relationship between the structure of amorphous alloy-polymer composites and their electromagnetic wave absorption properties, and to propose a new thinner electromagnetic wave absorber for several gigahertz frequency range. In order to achieve these objectives, various amorphous alloy-epoxy composites with different fabrication conditions such as amorphous alloy particle fraction, size have been fabricated using Fe73.5Si13.5B9Nb3Cu1 amorphous alloy nano particles. The electromagnetic properties of these composites including materials constants in high frequency and electromagnetic wave absorption properties have been invested.

우리나라 양파 가격 안정화 방안에 관한 연구 : 산지가격의 인과성 분석과 딥러닝을 활용한 가격예측을 중심으로

홍성민 강원대학교 대학원 2022 국내석사

농산물은 복잡한 유통구조와 날씨의 영향을 많이 받는 특성상 공급 불안정성이 내재하여 있으며 수요의 가격탄력성이 낮아 작은 공급변화에도 가격 변동성이 크게 나타난다. 이러한 원인 때문에 농산물은 2∼3년을 주기로 가격의 폭락과 폭등이 자주 발생하고 있다. 정부에서는 이러한 불안정한 농산물 가격 문제를 해결하고자 다양한 정책의 시행과 가격 예측을 하는 등의 노력을 하고 있다. 하지만 이러한 노력에도 불구하고 국내 농산물 가격 변동성은 미국, 일본 등의 국가와 비교할 때 매우 높은 편으로 정책의 효과성이 미흡한 편이다(김동환·류상모, 2016). 또한, 여전히 농산물 유통의 비효율성과 수급 불안으로 인해 가격의 급등락이 여러 번 발생하여 농가의 소득안정과 소비자의 가계 운영에 많은 어려움이 따르고 있다(감사원, 2017). 그중에서도 한국의 대표 조미채소 중 하나인 양파는 산지에서의 가격 형성기능이 미약하고, 수확기 출하 물량이 도매시장에 일시에 집중되면서 가격 등락 폭이 더욱 심화되고 있다(농림축산식품부, 2019). 따라서 양파를 비롯한 국내 농산물 가격안정화문제 해결을 위해 다양한 정책과 이와 관련된 연구가 필요한 시점이다. 본 연구의 목적은 국내 대표 조미채소 중 하나인 양파를 대상으로 가격안정화방안을 마련하는 것에 있다. 이를 위해 양파의 산지 가격을 권역별로 나누어 인과관계를 규명하여 가격선도를 이끄는 지역이 어디인지를 파악하고, 양파가격을 예측하여 농산물 가격 안정화 정책에 기반이 되는 연구를 하고자 한다. 먼저 양파가격이 산지 간의 어떤 인과성을 갖고 있으며, 가격선도가 일어나는 곳을 알아보기 위해 VAR 분석을 진행하였다. 분석 결과, 우리나라 최대 양파 주산지인 전라권(전남, 전북, 광주)이 산지 가격을 주도하는 것이 아닌 경상권(경남, 경북, 대구)에서 산지 가격을 주도하는 것으로 나타났다. 이런 원인으로는 다양한 원인이 있을 것이지만 양파의 유통구조 상의 특징에서 찾을 수 있다. 산지에서 출하된 양파는 대부분 가락시장이나 대구 공판장을 통해 가격이 형성되기 때문에 대구 공판장과 비교적 거리가 가까운 경상권의 가격이 타 권역에 영향을 미치는 것으로 추정되었다. 또한, 양파는 다른 농산물과 비교하여 저장성이 강해 생산량 대비 저장 비율이 높은 품목이다. 김성우 외(2016)에 의하면 국내 양파 저장업체의 현황은 경상권 445개 전라권 304개로 경상권의 저장업체 수가 더 많았다. 양파 저장업체 수가 해당 산지권역에 많이 분포되었다는 것은 산지가격에 반응하기 위한 충분한 시간적 여유가 있다는 것을 의미한다. 또 정현우 외(2017)에 의하면 전라도 지역의 농업생산기반시설이 경상도 지역보다 전반적으로 취약한 것으로 나타났다. 농업생산기반시설이 취약하다는 것은 양파품질 및 감모율에 영향을 미치기 때문이다. 다음으로 양파가격의 예측력을 향상하기 위해 구조모형과 머신러닝을 이용하여 양파의 도매시장 가격 예측력을 향상할 수 있는 모델을 구축하였다. 예측력 향상을 위한 예측모형 개발을 위해 양파 중기선행 관측모형을 구축하고 이를 월별로 재생산하여 단기 예측모형을 결합함으로써 일반 단기모형과 중기선행관측모형을 결합한 모형의 예측성을 분석했다. 머신러닝 분석에 양파 중기모형의 값을 반영하는 것은 머신러닝이 양파가격 예측을 위한 학습을 할 때 사전적 정보를 가지고 분석을 하는 것에 있어 중요한 의미가 있다. 분석결과 양파의 중기선행관측모형의 추정치 정보를 반영한 모형의 예측력이 더 높게 나타났다. 또한 머신러닝의 분석 성능에 대한 평가 지표로서 MAE, RMSE, MAPE를 활용하였다. 평가 결과 양파의 중기모형 정보를 반영한 LSTM모형과 반영하지 않은 LSTM모형의 가격 예측의 오차율은 각각 17.5%, 20.2%로 중기모형을 반영한 LSTM모형은 비교적 정확한 예측을 하는 것으로 나타났다. 반면, 중기모형을 반영하지 않은 LSTM모형은 비교적 합리적 예측을 하는 것으로 나타났다. 두 연구를 종합해 볼 때 향후 양파의 가격에 영향을 미치는 재고량에 관한 연구가 필요하다. 양파는 저장성이 강해 중·만생종은 수확기 저온저장 하여 9월 하순부터 출하되며, 매년 전체 생산량의 약 50∼60%가 저장되어 출하되고 있다. 본 연구에서는 양파의 재고량을 추정하여 예측 변수에 반영하였지만, 선행연구를 볼 때 재고량을 중심으로 한 연구는 많지 않다. 또 재고량의 경우 민간업체가 대부분 관리하여 정확한 물량 파악이 어려운 실정이다. 양파 가격안정화를 위해 다양한 노력이 필요하지만, 양파의 수급과 가격안정 체계를 효과적으로 이루기 위해서는 민간 저장업체의 적극적인 참여가 필요하다. 그리고 도매시장을 포함한 다양한 출하 장려금의 지원과 낙후된 저장창고 시설을 현대화하는 등의 서비스 제공을 검토할 필요가 있다. 정부와 지자체의 역할과 본 연구 결과를 기초로 양파 가격안정화 사업과 정책계획 수립에 있어 기초자료로 이용될 수 있을 것으로 기대한다. Unstable supply is inherent in Agricultural products due to complex distribution structure and its characteristics of being greatly affected by weather, and price fluctuation occurs often even with small changes in supply due to low price elasticity of demand. With these reasons, price slump and jump of agricultural products occur very often every two to three years. To solve the problem of this unstable price of agricultural products, the government is making effort such as implementing various policies and predicting prices. Despite these efforts, however, price fluctuation of domestic agricultural products is very high compared to that of USA and Japan and the effectiveness of policies are not sufficient (Kim Donghwan, Ryu Sangmo, 2016). In addition, the price slump and jump occured several times due to inefficiency in the distribution of agricultural products and unstable supply and demand, making many difficulties to stabilize rural household incomes and operate household finances of consumers (Gam Sawon, 2017). Onions, one of representative condiment vegetables in Korea, have weak function of price formation in the production area and the range of price fluctuation is getting deepen as the amount of shipment during the harvest time is concentrated in wholesale market at a time (Ministry of Agriculture, Food and Rural Affairs, 2019). Therefore, it is time when various policies and related studies are required to solve the issue of price stabilization of domestic agricultural products including onions. The purpose of this study is to prepare plans of price stabilization for onions, one of representative condiment vegetables in Korea. To do this, the study divided the price of onion production by region and identified the causal relationship to figure out the region that leads the price, and it predicted the price of onions to conduct study that can be the basis of price stabilization policy of agricultural products. First, VAR analysis was conducted to find out what kind of casual relationship onion price have between production areas and where price leadership occurs. The results of analysis found that Gyeongsangnam-do regions (Gyeongnam, Gyeongbuk, Daegu) is leading the price of production areas, not Jeollanam-do regions (Jeonnam, Jeonbuk, Gwangju), the largest onion producing areas in Korea. There may be various causes for this, but it can be found in the characteristics of distribution structure of onions. Since most of onions shipped from the production areas form their prices through Garak Market or Daegu joint market, it was estimated that the price in Gyeongsang regions where is relatively close to Daegu joint market affects other regions. In addition, onions has high stocking ratio compared to output with high storability unlike other agricultural products. According to Korea Rural Economic Institute (2016), the numbers of domestic storing enterprises in Gyeongsang regions were 445 which is more than Jeolla regions with 304. The fact that onion storing enterprises are distributed in these production areas mean that there is enough time to respond to the price of production area. In addition, Jeong Hyeonwoo et al., (2017) found that agricultural production infrastructure in Jeollado regions is vulnerable than that of Gyeongsangdo regions. This is because vulnerable agricultural production infrastructure affects the quality of onions and loss rate. Then, the model that can improve predictive power of the price in wholesales market of onions was built by using structural model and machine learning to improve the predictive power of onion price. To develop predictive model to improve predictive power, mid-term preceding observation model of onions was built and reproduced it monthly. And then it was combined with short-term predictive model to analyze the predictive power of model which was combined with general short-term and mid-term preceding observation model. Reflecting the value of mid-term model of onion in the machine learning has an important meaning in analyzing with prior information when machine learning learns to predict the price of onions. The results of analysis found that model reflecting estimated information of mid-term preceding observation model of onions had higher predictive power. In addition, MAE, RMSE and MAPE were used as an evaluation indicator for analysis performance of machine learning. As a result of evaluation, error rates of LSTM model that reflected mid-term model information of onions and LSTM model that didn't reflect it were 17.5% and 20.2% respectively, and this indicates that LSTM that reflected mid-term model showed relatively accurate predictions. On the other hand, LSTM model that didn't reflect mid-term model was found to have relatively reasonable prediction. When the both studies were combined, we can know that study on inventories affecting the price of onions is required in the future. Since onions have strong storability, medium and late maturing varieties are stored at low temperature during harvest time and shipped from the end of September. About 50 to 60% of total production is stored and shipped every year. This study estimated inventories of onions and reflected it to predictor variables, but there are not many preceding studies that focused on inventories. In addition, private enterprises usually manage the inventories, so it is hard to identify the accurate inventory. Various efforts are required to stabilize the price of onions, but active participation of private storing enterprises are also required to effectively achieve the supply and demand of onions and stable system of price. And it is necessary to review the provision of services such as supporting grants for various shipment including wholesale market and modernizing old storehouse facilities. Based on roles of government and local governments and the results of this study, it is expected that this can be used as a basic data for establishing stabilization project of onion price and policy planning.

십자가의 성 요한의 ‘무(無)’와 그리스도교적 ‘비움’의 영성 연구

홍성민 대전가톨릭대학교 대학원 2011 국내석사

모든 인간은 근본적으로 행복을 갈망한다. 태어나서부터 죽기까지 인간은 모두 완전하고, 영원한 행복을 얻기 위해 자신의 모든 것을 투신한다. 인간은 자신 안에 깊이 자리하고 있는 이 행복에 대한 갈망을 충족시키기 위해 한평생을 살아가는 것이다. 그런데 과연 이러한 행복은 어디서 찾을 수 있는 것일까? 모든 이들이 행복을 찾기 위해 일생을 바치지만 실제로 이것을 발견하고, 누리는 이들은 많지 않다. 이에 대해 그리스도교는, “진정한 행복이 부나, 안락에 있지 않고, 인간적인 영예나 권력에도 있지 않으며, 제아무리 유용해도 과학이나 기술, 예술 등 인간 업적에도 있지 않으며, 어떤 피조물 안에도 있지 않고 오로지 모든 선과 사랑의 근원이신 하느님께만 있다”고 선포하고 있다. 참된 행복은 오직 하느님 안에만 존재한다. 하느님께서는 “인간의 마음을 당신께 이끌기 위해 그 마음 안에 이 갈망을 심어주셨으며, 하느님께서는 이러한 갈망을 채워 주실 수 있는 유일한 분”이시다. 하느님 자신이 그 자체로 참된 행복이신 것이다. 그러므로 인간은 이러한 삼위일체 하느님과 친교 안에 참여 했을 때, 비로소 완전한 행복을 누리게 된다. 그렇다면 인간은 과연 어떻게 하느님과의 친교 안에 참여할 수 있는 것인가? 그리스도교 영성은 이에 대해 분명한 길을 제시하고 있다. 하지만 오늘날 이러한 가르침은 종종 균형을 잃은 채 그리스도인들에게 전해지는 경우가 있다. 현대의 그리스도인들은 하느님 안에서 참된 행복을 찾으려 하지만, 그들 중 많은 이들이 정작 자신들의 삶에는 큰 변화를 주지 않으려 한다. 그들은 마음의 평화와 기쁨, 즐거움을 누리려는 것에는 열정적이지만, 그것을 위해 반드시 요구되는 인간의 실제적인 응답과 협력은 소홀히 여기는 경향이 있다. 물론 모든 것은 언제나 하느님의 사랑과 은총에서부터 시작한다. 하느님께서 먼저 인간을 사랑하시고 참된 행복으로 이끌어 주시기에 인간이 응답할 수 있다는 것은 매우 당연한 일이다. 하느님의 이러한 사랑을 체험하고, 은총으로 충만할 때 인간은 비로소 참으로 변화될 수 있게 된다. 하지만 여기에서 또한 분명한 것은 그러한 사랑과 은총에 대한 인간의 응답 역시 반드시 필요하다는 것이다. 이것 없이 하느님께서는 인간 안에서 절대로 온전히 활동 하실 수 없다. 하지만 오늘 날 이러한 응답의 차원에 대해서는 조금 소홀하게 다루어지는 경향이 있으며, 또한 어떻게 인간이 응답을 해 나가야하는지 올바르고 분명히 제시되지 못하는 경우가 많다. 이러한 상황에 있어, 그리스도교 영성의 큰 스승인 “십자가의 성 요한”이 제시한 “무(無)”사상과 그리스도교의 “비움” 영성은 하느님과의 깊은 친교로 나아가는 길을 가장 분명하게 제시해 줄 것이라 생각된다. 본 논문의 목적은 다음과 같다. 첫째, 십자가의 성 요한의 “무(無)”사상과 그리스도교 “비움”영성이 가지고 있는 의미를 알아보고 그 관계를 고찰해 볼 것이다. 이 작업을 통해 그리스도교 영성이 가지고 있는 참된 의미와 가치를 제시하려 한다. 둘째, “무(無)”와 “비움”의 영성을 통해 오늘날 그리스도교 신자들에게 반드시 필요한 신앙인의 자세가 무엇인지 제시하고자 한다. 그리고 이 두 가지의 길을 통해서 삼위일체이신 하느님과의 친교에 참여할 수 있다는 사실을 보여주고자 한다. How can I live a true happy life? What should I do for it? Everyone in the world asks this question in his(or her) life time. Indeed, happiness is a sole purpose of human being. All the people want to be happy and do everything as much as they can do to grasp it. Then, where can we find that true happiness? Church has taught that there is a true happiness in herself. That was revealed in Jesus Christ, "the way, the truth, and the life." Every christian is invited to eternal happiness through Jesus. Only Jesus can lead us to true happiness. What is important, however, in this process is answer from us, human being. God does not lead us against our will. He always respect our free will and invite us to a way of true happiness, love and communion. It is, therefore, always important matter "how do we answer the His call." 'Nada' of St. John of the Cross and 'kenosis' of Christianity show us good way that we can answer God's call. Actually it is not a brand-new teaching. Both 'nada' of St. John of the Cross and 'kenosis' of Christianity have a single goal which is following the way of Jesus Christ thoroughly. Look into Jesus Christ only, imitate him and finally unite with him is a spirit of 'nada' and 'kenosis'. There are, however, to be many difficulties and great agony, and it needs thorough renunciation and abandonment of self because it is a way of imitating God as a human. Still, the faithful who walk that way would experience true happiness is growing up in theirselves. Many people get thirsty about spirituality. They want to experience God or Absolute One, and enjoy peace and joy in Him. Whoever seeks the peace and joy only, would not get true happiness which God wants in us. Because true happiness is in communion of Triune God only, and there needs great change from us to participate the communion. Jesus, therefore, clearly said to his disciples and crowds that "Whosoever will come after me, let him deny himself, and take up his cross, and follow me." Jesus Christ is "the way, the truth and the life." To get true happiness, human being should follow this way. And the "nada" of St. John of the Cross and "kenosis" of Christianity will be a good guide to follow this way rightly.