WIND ENERGY POTENTIAL ASSESMENT and SITING a WIND FARM in CHEJU ISLAND

김건훈,조경호,고장권,허종철,고경남 濟州大學校 工科大學 産業技術硏究所 1997 尖端技術硏究所論文集 Vol.8 No.2

본 연구는 제주도내 풍력발전기 보급 및 적지선정을 검토하는데 그 목적을 두었다. 이를 위하여 제주도내 다풍지역으로 예상되는 3개지역을 선정하여 1년간 풍력자원조사를 행하였고, 계측된 자료는 통계분석으로 풍력자원을 정량화하였으며 또한 세계적으로 경제성이 인증된 600kW 풍력발전기를 모델로하여 가상 출력을 산출함으로서 최적 풍력단지를 제시하였다. The possibility in the practical use and supply of the wind turbine in Cheju island was investigated. The wind data measured in three regions which have a plenty wind energy potential were utilized to quantify the wind power resources by statistical analysis. Power output was calculated for 600 kW wind turbine. The coastal area of Guja was superior to Daejung and Hoichun in wind power energy densities. The calculated capacity factor of 600 kW wind turbine in this site was high as much as 30%. Hoichun site, the intermediate region between the Halla mountain and the sea, was rich in wind power energy resources in winter. Hourly ideal energy density at three regions increased at sunrise, reached the maximum at 13-16 O'clock, decreased steadily, and finally remained constant at sunset.

심인성 색전 요인이 없는 뇌경색 환자에서 경식도 심초음파와 Acoustic Quantification을 이용한 대동맥 탄성의 평가

이종민,윤호중,임효영,박지원,김휘열,전희경,문건웅,정욱성,채장성,김재형,최규보,홍순조 대한순환기학회 2000 Korean Circulation Journal Vol.30 No.8

WIND ENERGY POTENTIAL ASSESMENT and SITING a WIND FARM in CHEJU ISLAND

고경남,김건훈,조경호,고장권,허종철 濟州大學校 産業技術硏究所 1997 산업기술연구소논문집 Vol.8 No.2

The possibility in the practical use and supply of the wind turbine in Cheju island was investigated. The wind data measured in three regions which have a plenty wind energy potential were utilized to quantify the wind power resources by statistical analysis. Power output was calculated for 600 kW wind turbine. The coastal area of Guja was superior to Daejung and Hoichun in wind power energy densities. The calculated capacity factor of 600 kW wind turbine in this site was high as much as 30%. Hoichun site. the intermediate region between the Halla mountain and the sea. was rich in wind power energy resources in winter. Hourly ideal energy density at three regions increased at sunrise, reached the maximum a t 13-16 O'clock, decreased steadily, and finally remained constant at sunset.

How to Combine Diffusion-Weighted and T2-Weighted Imaging for MRI Assessment of Pathologic Complete Response to Neoadjuvant Chemoradiotherapy in Patients with Rectal Cancer?

Jang Jong Keon,이철민,Park Seong Ho,Kim Jong Hoon,Kim Jihun,Lim Seok-Byung,Yu Chang Sik,Kim Jin Cheon 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.9

Objective: Adequate methods of combining T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) to assess complete response (CR) to chemoradiotherapy (CRT) for rectal cancer are obscure. We aimed to determine an algorithm for combining T2WI and DWI to optimally suggest CR on MRI using visual assessment. Materials and Methods: We included 376 patients (male:female, 256:120; mean age ± standard deviation, 59.7 ± 11.1 years) who had undergone long-course CRT for rectal cancer and both pre- and post-CRT high-resolution rectal MRI during 2017– 2018. Two experienced radiologists independently evaluated whether a tumor signal was absent, representing CR, on both post-CRT T2WI and DWI, and whether the pre-treatment DWI showed homogeneous hyperintensity throughout the lesion. Algorithms for combining T2WI and DWI were as follows: ‘AND,’ if both showed CR; ‘OR,’ if any one showed CR; and ‘conditional OR,’ if T2WI showed CR or DWI showed CR after the pre-treatment DWI showed homogeneous hyperintensity. Their efficacies for diagnosing pathologic CR (pCR) were determined in comparison with T2WI alone. Results: Sixty-nine patients (18.4%) had pCR. AND had a lower sensitivity without statistical significance (vs. 62.3% [43/69]; 59.4% [41/69], p = 0.500) and a significantly higher specificity (vs. 87.0% [267/307]; 90.2% [277/307], p = 0.002) than those of T2WI. Both OR and conditional OR combinations resulted in a large increase in sensitivity (vs. 62.3% [43/69]; 81.2% [56/69], p < 0.001; and 73.9% [51/69], p = 0.008, respectively) and a large decrease in specificity (vs. 87.0% [267/307]; 57.0% [175/307], p < 0.001; and 69.1% [212/307], p < 0.001, respectively) as compared with T2WI, ultimately creating additional false interpretations of CR more frequently than additional identification of patients with pCR. Conclusion: AND combination of T2WI and DWI is an appropriate strategy for suggesting CR using visual assessment of MRI after CRT for rectal cancer.

Accuracy of the ultrasound attenuation coefficient for the evaluation of hepatic steatosis: a systematic review and meta-analysis of prospective studies

Jang Jong Keon,최상현,Lee Ji Sung,Kim So Yeon,Lee Seung Soo,Kim Kyung Won 대한초음파의학회 2022 ULTRASONOGRAPHY Vol.41 No.1

Purpose: The accurate detection and quantification of hepatic steatosis using a noninvasive method are important for the management of nonalcoholic fatty liver disease. We performed a systematic review and meta-analysis of the accuracy of the ultrasound-measured attenuation coefficient (AC) in the evaluation of hepatic steatosis. Methods: The PubMed, Embase, and Cochrane databases were searched for prospective studies reporting the diagnostic accuracy of AC for assessing hepatic steatosis. The meta-analytic pooled sensitivity and specificity of AC for any grade of steatosis (S≥1) and advanced steatosis (S≥2) were estimated using a bivariate random-effects model. Meta-regression analysis was conducted to investigate the causes of heterogeneity among studies. Results: Thirteen studies including 1,509 patients were identified. The pooled sensitivity and specificity of AC for S≥1 were 76% (95% confidence interval [CI], 73% to 80%; I2 =43%) and 84% (95% CI, 77% to 89%; I2 =74%), respectively, while for S≥2 they were 87% (95% CI, 83% to 91%; I2 =0%) and 79% (95% CI, 75% to 83%; I2 =59%), respectively. Study heterogeneity was associated with body mass index (BMI) and the prevalence of steatosis or significant fibrosis. Conclusion: AC can be clinically useful for assessing hepatic steatosis, with good overall diagnostic performance. The data reported in the published literature differed according to BMI and the prevalence of steatosis or significant fibrosis, and careful interpretation with consideration of these factors might be needed. Purpose: The accurate detection and quantification of hepatic steatosis using a noninvasive method are important for the management of nonalcoholic fatty liver disease. We performed a systematic review and meta-analysis of the accuracy of the ultrasound-measured attenuation coefficient (AC) in the evaluation of hepatic steatosis.Methods: The PubMed, Embase, and Cochrane databases were searched for prospective studies reporting the diagnostic accuracy of AC for assessing hepatic steatosis. The meta-analytic pooled sensitivity and specificity of AC for any grade of steatosis (S≥1) and advanced steatosis (S≥2) were estimated using a bivariate random-effects model. Meta-regression analysis was conducted to investigate the causes of heterogeneity among studies.Results: Thirteen studies including 1,509 patients were identified. The pooled sensitivity and specificity of AC for S≥1 were 76% (95% confidence interval [CI], 73% to 80%; I2=43%) and 84% (95% CI, 77% to 89%; I2=74%), respectively, while for S≥2 they were 87% (95% CI, 83% to 91%; I2=0%) and 79% (95% CI, 75% to 83%; I2=59%), respectively. Study heterogeneity was associated with body mass index (BMI) and the prevalence of steatosis or significant fibrosis.Conclusion: AC can be clinically useful for assessing hepatic steatosis, with good overall diagnostic performance. The data reported in the published literature differed according to BMI and the prevalence of steatosis or significant fibrosis, and careful interpretation with consideration of these factors might be needed.

무도의 교육적 적용 가능성과 한계

장재이,최종균,허건식 선문대학교 자연과학대학 2000 자연과학논총 Vol.3 No.-

유리재료의 활용 중, 회토류 원소를 첨가한 유리의 up-conversion 현상은 여기 광원으로 고출력의 적외선 반도체 laser를 이용할 수 있기 때문에 효율을 높일 수 있다면 실용적인 단파장 laser 광원으로 사용이 유력시되고 있다. 본 연구에서는 현재 상용화된 반도체 laser중 고출력을 얻을 수 있는 800nm 대역을 이용하여 회토류 원소들을 phonon energy가 상대적으로 작은 fluoride 유리에 복합 첨가하여 청색대(480nm)의 가시광선을 얻는 up-convertor 용 기지유리를 제조하고자 하였다. Fluoride 유리의 제조 기술은 fluoride 화합물들의 특별한 화학적 성질로 인하여 제조가 어려워 일반 산화물 유리에 비하여 매우 기초적인 단계에 있다. 따라서 본 연구에서는 up-convertor 개발을 위해 fluoride 유리의 제조와 회토류 원소 첨가에 수반되는 물리 화학적 성질의 규명에 주력하고자 하였다. 5가지 회토류 원소들을 복합 첨가한 10가지 종류의 회토류 복합 첨가 fluoride 유리들을 수소(N_(2)) 분위기의 glove-box내에서 제조하여 유리화, 용융성, 유리전이온도, 결정화 온도, 밀도, chemical durability, 경도, 굴절률 등의 기본적인 유리의 물성 들을 분석을 하였다. Up-conversion of rare-earth elements added glasses is promising area for short wavelength laser source by utilizing high power semiconductor infra-red laser if the efficiency can be increased by proper method. In this study, relatively low phonon energy fluoride glasses were prepared by co-doping rare-earth elements for up-converter of fluorescences at 480nm wavelength (blue up-conversion) with commercial 800nm semiconductor laser. Preparation of fluoride glasses is very difficult because of special properties of fluoride chemicals. In this research, effort was concentrated on the preparation of fluoride glasses with the rare-earth combinations to realize a good medium for the high efficiency up-convertor. The physical, chemical, and optical properties of co-doped fluoride glasses were measured. Since the difficulties of handling and melting of fluoride glasses, it is its early stage for making fluoride glasses. 10 combinations of 5 different rare-earth fluoride elements doped samples were prepared inside the glove-box which filled with nitrogen gas and their glass transition temperatures, crystallization temperatures, chemical durabilities, densities, hardness, and refractive indices, were measured.

Designing Primers from Multiple Sequences Using Matchup Program to Improve Detection of Hepatitis B Virus by Polymerase Chain Reaction

Jang, So-Young,Kim, Mi-Suk,Park, Min-Seok,Lee, Keon-Myung,Chung, Hwan-Won,Chun, Jong-Sik,Lee, Chan-Hee 한국미생물학회 2010 The journal of microbiology Vol.48 No.1

Traditionally primers for PCR detection of viruses have been selected from genomic sequence of single or representative viral strain. However, high mutation rate of viral genomes often results in failure in detecting viruses in clinical and environmental samples. Thus, it seems necessary to consider primers designed from multiple viral sequences in order to improve detection of viral variants. Matchup is a program intended to select universal primers from multiple sequences. We designed using Matchup program primer pairs for HBV detection from 691 full genomic HBV DNA sequences available from NCBI GenBank database. Thousands of primer candidates were initially extracted and these were sequentially filtered down to 5 primer pairs. These primer pairs were tested by PCR using 5 HBV Korean HBsAg(+) patient sera, and eventually one universal primer pair was selected and named MUW (multiple-universal-worldwide). This primer pair, 3 HBV reference primer pairs reported by others and 1 commercial primer pair were compared using 86 HBV HBsAg(+) sera from Korean and Vietnamese patients. The detection rate for MUW primer pair was 72.1%, much greater than those obtained by reference and commercial primers (32.5 to 40.7%). The superiority of MUW primer pair appeared to be correlated with the conserved sequences of the forward primer binding sites and primer quality score. These results suggest that the universal primers designed by the Matchup program from multiple sequences could be useful in detecting viruses from clinical samples.

우리나라 검도의 도입기 양상

장재이,최종균,허건식 선문대학교 자연과학대학 2000 자연과학논총 Vol.3 No.-

건축허가업무의 경영혁신을 모색하고 있는 중견규모의 일본건축업체를 대상으로, 일본형 6시그마이론을 적용한 BPR활동의 실제사례를 소개하는 것이다. 현장을 중시하는 경향이 매우 강한 건축업체의 경영혁신방법론 중 가장 효율적인 방법론을 선정하기 위하여 여러 종류의 방법론을 벤치마킹하여 6시그마 방법론을 선정하였다. 현장중심의 성격이 강한 일본의 고유한 기업환경에서 일반적인 6시그마이론을 적용하기 어려운 부분과 고유한 6시그마를 도입하는 과정에서 그대로 받아들이기 힘든 부분도 있었다. 이 문제 해결을 위해 일본 기업이 6시그마를 적용하는데 보다 효율적으로 도입할 수 있는 새로운 일본형 6시그마 방법론을 적용하도록 하였다. 일본의 기업환경을 고려한 일본형 6시그마 방법론에 근거하여 6시그마 추진 process인 MAIC(측정, 분석, 개선, 정착을 위한 관리)에 따라 BPR활동을 전개하였다. 건축허가업무를 대상으로 하여 새로운 6시그마 방법론에 의거한 적용 결과, 당초 예상한 것보다 훨씬 좋은 목표를 달성할 수 있었다.

Catalytic behavior of Sn/Bi metal powder in anhydride-based epoxy curing.

Jang, Keon-Soo,Eom, Yong-Sung,Moon, Jong-Tae,Oh, Yong-Soo,Nam, Jae-Do American Scientific Publishers 2009 Journal of Nanoscience and Nanotechnology Vol.9 No.12

<P>In this paper, we report the catalytic activity of the Sn/Bi alloy beads and its acceleration of the exothermic epoxy curing reactions in various thermal conditions and bead compositions. As being used as low-melting solder balls in electronic interconnection processes with various epoxy systems, it was found that the Sn/Bi beads substantially lowered the exothermic peak temperature of the diglycidyl ether of bisphenol A (DGEBA)/anhydride systems in up to ca. 140 degrees C depending on different types of anhydride curing agents. The catalytic activation of Sn/Bi powder was initiated with a small amount of Sn/Bi powder, for example, lowering ca. 50 degrees C of the exothermic peak temperature by adding only 0.1 vol% of Sn/Bi powder. The catalytic capability of the powder was increased by using smaller sized beads corresponding to larger catalytic surface area at the same volume fraction. Exhibiting a latent catalytic effect, the catalytic activity of Sn/Bi powder was remained latent at temperatures lower than 100 degrees C in isothermal conditions.</P>

한강수계 2개 유형 고도처리 정수장의 2-MIB 처리 특성 비교 분석 및 공정 운영 최적화 연구

박종일(Jong-Il Park),이영(Young Lee),장경아(Kyoung-A Jang),김건회(Keon-Hoi Kim),이태훈(Tae-Hoon Lee),김선욱(Sun-Wook Kim) 대한환경공학회 2020 대한환경공학회지 Vol.42 No.12

목적: 본 연구에서는 동일한 취수장에서 원수를 취수하는 상이한 2개 유형 고도처리 정수장(Post Peroxone+GAC, UV/H₂O₂+GAC F/A)의 고농도 2-MIB (2-Methyl Isoborneol) 대응 결과를 통하여 각 정수장의 산화 공정별 2-MIB 제거 특성을 비교 분석하고 최적 운영 방안을 도출하였다. 방법: Post Peroxone+GAC (Granular Activated Carbon)가 도입된 G정수장과 UV/H₂O₂+GAC F/A가 도입된 I정수장의 고도산화공정(Advanced Oxidation Process, AOP) 운영 조건에 따른 2-MIB 처리율을 비교 분석하였다. 정수장별 AOP 운영 조건과 2-MIB 제거율의 상관관계를 통하여 최적 약품 주입률 산정식을 도출하고, 각 정수장별 공정 운영 특성을 분석하여 원수 2-MIB 농도 및 용수생산량에 따른 최적 운영 시의 소요 비용과 원단위를 산정하였다. 각 정수장 산화 설비의 성능 평가 결과 및 약품 주입률 산정식을 통해 최적 운영 조건을 도출하였으며, 연계운영을 통한 경제적인 대응 방안을 검토하였다. 결과 및 토의 : 정수장별 2-MIB 제거율은 G정수장 70~100%, I정수장 50~96%로 나타났다. 2-MIB 제거에 영향을 미치는 운영 조건은 Post Peroxone은 [O₃ 주입률× 접촉시간]과 H₂O₂/O₃, UV/H₂O₂는 [UV 조사량 × H₂O₂ 주입률]이었다. 각 정수장의 운영비(전력비+약품 구매비) 원단위 비교 결과, I정수장이 G정수장보다 6.6~24.3원/m³ 높았다. 이는 UV/H₂O₂의 H₂O₂ 주입률이 Post Peroxone 대비 11~43배였기 때문인 것으로 사료된다. 각 정수장 산화 설비의 성능평가 결과 및 약품 주입률 산정식을 통해 최적 운영 조건을 도출할 수 있었다. G정수장과 I정수장의 송수관로에는 연계운영을 위한 배관이 설치되어 있어 각 정수장별 용수생산량의 배분이 가능하다. 용수생산량이 동일할 경우, G정수장의 용수생산비율을 높일 때 G정수장의 원단위 상승비용보다 I정수장의 원단위 감소비용이 더 크기 때문에 원단위 절감이 가능함을 확인할 수 있었다. 결론: G정수장의 Post Peroxone+GAC, I정수장의 UV/H₂O₂+GAC F/A 모두 2-MIB 처리에 효과적임을 확인할 수 있었다. 운영비용의 경우, UV/H₂O₂가 H₂O₂의 주입량이 많아 Post Peroxone보다 원단위가 높은 것으로 분석되었다. 각 정수장의 공정별 2-MIB 처리율과 운영비를 고려하여, 정수장별 최적 운영 조건과 연계운영 방안을 도출할 수 있었다. Objectives : In this study, through the results of the high-concentration 2-MIB (2-Methyl Isoborneol) treatment by two different types of advanced treatment plants (Post Peroxone+GAC, UV/H₂O₂+GAC F/A) which intake raw water from the same water intake facility, the 2-MIB removal characteristics by oxidation process of each WTPs (Water Treatment Plants) were compared and analyzed, and optimal operation methods were derived. Methods : The 2-MIB removal rate was compared and analyzed according to each AOP (Advanced Oxidation Process) operating conditions (Post Peroxone+GAC of the G WTP and UV/H₂O₂+GAC F /A o f the I WTP ). The optimal equations of chemical injection were derived through the correlation between the operating conditions of the AOP for each WTPs and 2-MIB removal rate. By analyzing the operating characteristics of each WTPs, the cost and unit price for optimal operation were calculated according to the 2-MIB concentration of raw water and water production. Optimal operating conditions were derived through the performance of oxidation facilities and chemical injection equations of each WTPs, and economical operating plans were reviewed through linked operation of 2 WTPs. Results and Discussion : The 2-MIB removal rates for each WTPs were 70~100% for the G WTP and 50~96% for the I WTP. The operating conditions affecting the 2-MIB removal were [O₃ injection × contact time], H₂O₂/O₃ for Post Peroxone of the G WTP, and [UV dose × H₂O₂ injection] for UV/H₂O₂ of the I WTP. As a result of comparing the operating cost(electric power cost + chemical cost) of each WTPs, I WTP was 6.6~24.3 KRW/m³ higher than G WTP. It is considered to be because the H₂O₂ injection was 11~43 times for UV/H₂O₂ than Post Peroxone. Optimal operating conditions could be derived through the performance evaluation of each oxidation facilities and chemical injection equations of each WTPs. The G WTP and the I WTP are equipped with pipe line for linked operation in the water supply pipes, so the water production for each WTPs can be distributed. In the case of the same water production, it was confirmed that the unit price can be reduced when the water production ratio of the G WTP is increased. Because the decrease in cost of the I WTP is higher than the increase in cost of the G WTP . Conclusions : It was confirmed that both Post Peroxone+GAC of G WTP and UV/H₂O₂+GAC F /A of I WTP were effective in 2-MIB treatment. As for the operating cost, it was analyzed that UV/H₂O₂ had higher unit pice than Post Peroxone because of the large amount of H₂O₂ injection. Considering the 2-MIB removal rate and operating cost of each WTPs, it was possible to derive the optimal operating conditions for each WTPs and a linked operation plan.