롤포밍 공정에서의 성형방법에 따른 직진성 예측

정상화,이상희,김재상,박진완,임성빈 朝鮮大學校 機械技術硏究所 2007 機械技術硏究 Vol.10 No.2

Roll forming process is one of the most widely used processes in the world for forming metals. It can manufacture goods of the uniform cross section throughout the continuous processing. However, analysis of process is very difficult because of the inherent complexity of the process. For this reason, the computer analysis methods such as the FEM(Finite Element Method) and the FDM(Finite Difference Method) are frequently used in roll forming design. In this paper, the under rail composed of upper member, center member and lower member is modeled. Also the flower pattern of the upper member is designed and the roll forming process is simulated. The upper member is designed using constant arc length forming method and constant radius forming method for excellent design. The cold rolled carbon steel sheet(SCP-l) is used in this simulation, and a flow stress equation is set up through the tensile test. Each types are simulated and compared with the longitudinal strain using SHAPE-RF software. In addition. the numerical magnitude of camber and bow is predicted from the results of the simulation.

동아시아 FTA Hub 전략의 경제적 효과와 타당성 검토

정재화,정인교 韓國東北亞經濟學會 2009 동북아경제연구 Vol.21 No.1

East Asian countries have continued to pursue an active FTA policy since the 1997 Asian financial crisis. In the region, ASEAN+1 type of FTAs are already in effect or have been concluded between the ASEAN and the three Northeast Asian countries (Korea, Japan, China) along with the deeper integration of the AFTA which combines the ten ASEAN member countries. At the same time, active discussions have been conducted on a possible FTA that covers the entire East Asian region, an East Asia FTA (EAFTA). If this EAFTA is concluded, it is expected to surpass the size of NAFTA and to have even greater ripple effects. According to the CGE analysis on the economic effects of an East Asia FTA (EAFTA), the FTA is expected to be beneficial to the countries in the region. A regional FTA among countries in Northeast Asia or East Asia will have greater rewards than bilateral FTAs between two countries. In particular, Korea is deemed to be the greatest beneficiary of an EAFTA. And if China and Japan do not conclude an FTA and Korea concludes FTAs with ASEAN China and Japan and becomes an East Asian FTA hub, the economic effects are expected to be even greater. Notwithstanding the economic benefits that come from being an FTA hub, the merits of an East Asia FTA covering the entire region will be even greater. First of all, it will be possible to lower the rising transaction costs that ensue from the intertwined regional FTA network Also, higher economic efficiency is expected in the mid-term and long-term from the harmonization of the different systems. Therefore, the straightforward strategy for Korea would be to pursue an East Asia FTA and strategically promote FTAs with Japan and China to get a strategic advantage in the future East Asia FTA negotiation process. In fact, under the current situation in which an FTA among the three major countries in Northeast Asia, Korea, China and Japan, is deterred by various obstacles, an East Asia FTA could be the favored alternative. This is because an FTA combining the entire region could alleviate the conflicting interests of individual industry sectors that may arise from a bilateral FTA. In addition, it would be possible to establish a more flexible level of trade liberalization in goods under an East Asia FTA.

산후의 우울 증상과 연관된 심리사회적 및 산과적 변인

김재원,김정화,김병조 大韓神經精神醫學會 2005 신경정신의학 Vol.44 No.2

Objectives : The purpose of this study is to examine the psychosocial and obstetric factors associated with postpartum de-pressive symptoms in Korea. Methods : At the 1-week and 4-week postpartum visit, 61 postpartum women completed Edinburgh Postnatal Depression Scale (EPDS), Beck Depression Inventory (BDI), Stait-Trait Anxiety Inventory (STAI), and Symptom Check List-90-Revised (SCL-90-R). Data related to psychiatric and obstetric characteristics, pregnancy and delivery related events were collected from standard medical records. 42 women without a history of pregnancy or delivery within 6 months were recmited as a control group. The postpartum group were divided into depressive and non-depressive groups according to the EPDS and BDI results of 4-week postpartum. Results : Compared to the normal control group, the mean scores of EPDS and BDI at 1-week postpartum were significantly higher (p<.05 and p<.01, respectively) in the postpartum group. The postpartum group also scored significantly higher in the somatization, Psychoticism, and global severity index profiles according to the SCL-90-R results (p<.05). The mean score of BDI at 4-week postpartum was significantly higher (p<.01) in the postpartum group. There were significant correlations (p<.01) between the EPDS and BDI reports at 1- and 4-week postpartum. The rates of having experienced severe emotionalstress during pregnancy and of smokers and drinkers before pregnancy were significantly higher (p<.05) in the postpartum depressive group (EPDS ≥10 and BDI ≥ 10) compared to the postpartum non-depressive group. The rate of having experi-enced depressive symptoms at 1-week postpartum was also significantly higher in the postpartum group. The depressive sym-ptomatology at 1-week postpartum was identified as a significant risk factor for the depressive symptoms of 4-week postpartum when multiple logistic regression analysis was performed after controlling for age and education level. Conclusion : These findings suggest that postpartum women in Korea have many psychiatric problems such as depressive mood and somatization which necessitate proper care and assessment during the early postpartum period. Stress management during pregnancy may be helpful as a measure of preventing postpartum depression.

도서지역 특기적성교육 운영실태와 개선방안에 관한 연구

이재화,정회욱 木浦大學校敎育硏究所 2005 교육연구 Vol.18 No.-

본 연구는 정규 학교수업이 끝난 후에 비어 있는 학교의 시설과 공간을 활용하여 학생들의 소질과 적성을 계발하고 잠재력을 발연시키는 다양하고 흥미 있는 특기·적성교육의 운영 실태 파악과 개선 방안을 제시하는데 의의가 있다. 이러한 연구목적을 달성하기 위하여 구체적으로 특기·적성교육목적 및 필요성의 실현정도, 특기·적성교육의 내용과 방법, 특기·적성교육의 지도교사 운영, 특기·적성교육의 효과 및 평가 영역에 관한 내용을 전남 서남부 도서지역을 대상으로 146명의 중학교 교사로 부터 설문조사를 실시하였다. 자료 분석 결과를 요약하면 다음과 같다. 첫째, 특기적성교육의 필요성과 목적으로 대부분의 교사들이 필요하며 특기지도라고 응답했다. 둘째. 특기·적성교육의 내용 선정은 학생과 학부모의 요구가 높게 반영되고 교육방안에 대해서는 실험실 습식 교육이 적당하며 교과관련 영역이 포함되어있다고 응답했다. 셋째, 지도교사가 느끼는 가장 큰 애로사항에 대해서는 전문성 부족이 높게 나타났는데 성별에서는 남교사가, 교육경력별에서는 11년 이상 된 교사들이 더 전문성 부족을 이유로 들었다. 넷째, 특기·적성교육의 전반적인 효과가 있고 특기신장 목표영역이 높게 나타났다. 이러한 연구 결과에 비추어 볼 때, 특기·적성교육의 본래의 목적과 취지에는 충분히 공감하면서도 현실적으로 역부족인 부분을 활성화시키기 위해서는 교과관련과 비교과 관련 특기·적성 교육활동에 필요한 교육시설 등의 교육여건을 구비해야 하며, 학부모의 평가 및 참여를 유도해야 한다. 또한 교사의 업무 부담 경감과 학생의 특기·적성 교육활동에 적극적·자발적 참여를 유도하고, 다양한 방과 후 교육프로그램을 개설하고 자질 있는 강사를 확보하기 위해서도 특기·적성 교육활동에 필요한 운영비는 지원을 확대해야 한다. This study is worth analyzing practices of special Ability and Aptitude Education in the islands area and suggesting their improvements in order that they are firmly established in this area. For the purpose of this study, the author was investigated for teachers in the 25 middle schools located in the southwest islands of Cheonnam province(Shinan, Chindo, Wando) Measuring tool is a questionnaire, which is composed of accomplishment degree of its necessity and the purpose of special ability and Aptitude Education, its contents and method, management of the teachers in the charge of it, its effect and evaluation. The results are as following. First, special ability and aptitude promoting in each school be managed for students' capability development as its original purposes, and in order to manage the carious programs students and their parents demand, and th reduce private tuition fee, each school must manage higher level education. Above all for maintaining this, parents' trust in the special Ability and aptitude must go ahead. Second, each school need teach individually through level management or supplementary·advanced class and draw up curricular for developing students' creativity and variety. We are suffering from the lack of carious programs and teachers in charge that parents demand, but we will be able to expect more educational rising efficiency of we use human·material resources of the community much better. Third, school authorities should select able inner teachers and outer part-time teachers in change of special ability and Aptitude. Especially in the islands area school must prepare for the management method reflecting in the lack of human resources and some reaching problems according to long distance, the lack of teachers results in less fee than the other areas. Fourth, school authorities should try to regain the confidence in the public education through the special ability and Aptitude Education. For this, each school should offer teachers chances to train for them selves and evaluate in many ways like opening their classes and presenting their cases and connect with the festivals of teenagers. And each school need th evaluate it frequently and give a feedback so as to reflect the results of all the evaluations in the next term management of special ability and Aptitude Education.

STZ 유발 당뇨쥐에서 시간에 따른 생리적 항산화계의 변화

이순재,양정아,김성옥,최정화,신주영,채영미,차복경 대구효성가톨릭대학교 응용과학연구소 1997 응용과학연구논문집 Vol.5 No.-

The purpose of this study was to investigate change of physiological antioxidative system according to the time in streptozotocin-induced diabetic rats. Sprague-Dawley male rats weighing 150±10gm were randomly assigned to one normal and five STZ-induced diabetic groups. Diabetic groups were classified to experimental period. Diabetes was experimentally induced by intravenous injection of 55 mg/kg of body weight of STZ in citrate buffer(PH 4.3) after 6 weeks feeding of three experimental diets. Animals were sacrificed at 0, 3, 6, 12, 18th days of diabetic states. 1. Activity of superoxide dismutase(SOD) in liver was increased in that of diabetic mellitus(DM) groups at 3th day but that of DM groups was not significant from 6th day according to period. Glutathion peroxidase(GPX) was significantly decreased in DM groups from 6th day 2. Reduced glutathione(GSH) contents in liver significantly decreased in diabetic groups from 3rd day compared with those of DM groups according to the period. Oxidized glutathione(GSSG) was higher from 6th day. GSH/GSSG ratio was significantly lower than that of normal group from 3rd day to all experimental period 3. Contents of vitamin E in liver of DM groups were significantly decreased compared with that of normal group from 6th day. 4. Lipid peroxide(LPO) contents in liver of DM groups were significantly increased compared with that of normal group from 3rd day. The present results indicate that STZ-induced diabetic rats were reduced by antioxidative defense system and taken by peroxidate damage in tissue compared with normal group from 3rd day or 6rd day after injection STZ. It lended to acceleration all diabetic groups but no significance according to the experimental time.

결핵균 30 kDa 항원과 Triton X-100 Solubilized Protein 항원에 의한 대장암 주변 림프절 단핵구의 활성화

박정규,김광호,조은경,임재현,민들레,송영자,김화중,백태현 忠南大學校 癌共同硏究所 1998 癌共同硏究所 硏究誌 Vol.2 No.1

Tumor-draining lymph node mononuclear (TDLMN) cells are specifically sensitized to the growing tumor but such cells are deficient for mediating an antitumor response. In this study, we examined the feasibility of using mycobacterial 30 kDa or Triton X-100 solubilized protein (TSP) antigen to stimulate mononuclear cells of colon cancer-draining lymph node for the generation of cell mediated immune effector cells. The proliferative response of TDLMN cells stimulated with mycobacterial 30 kDa or TSP antigen was determined by ^(3)H-thymidine incorporation assay. The proliferation of TDLMN cells to mycobacterial 30 kDa or TSP antigen was significantly increased in PPD (+) patients, but a poor response to the 30 kDa or TSP antigen was observed in PPD (-). The expression on γδ T cells to mycobacterial 30 kDa or TSP antigen was assessed by flow cytometry. The γδ T cells from PPD ( + ) patient responded only to 30 kDa antigen but to TSP antigen. An investigation of cytokine mRNA expression was undertaken using reverse transcription-polymerase chain reaction (RT-PCR) to follow TDLMN cells stimulated with the 30 kDa or TSP antigens for 5 days. The IFN-γ and TNF-α mRNA expression was only induced in TDLMN cells of PPD ( + ) patient in response to the 30 kDa or TSP antigen. The IL-2 mRNA expression was induced in both PPD (+) and PPD (-) in response to the 30 kDa or TSP antigen. But the IL-4 mRNA expression was not induced in response to the 30 kDa or TSP antigen. These results suggest that the 30 kDa and TSP antigens may serve as biologic response modifier for the generation of cell mediated immune effector cells.

결핵항원에 의한 결핵환자 말초혈액 단핵구의 IL-2,IL-10 및 TNF-α mRNA 발현비교

박정규,임영재,김화중,조은경,민들레,임재현,최덕례,박성규 충남대학교 의과대학 지역사회의학연구소 1999 충남의대잡지 Vol.26 No.1

The various clinical features of tuberculosis are mediated by diverse cytokines produced by various immune cells which are initially triggered by M. tuberculosis antigens. CD4+ T cells can be classified into two subsets according to the patterns of cytokines they produce; Thl cells give rise to cell-mediated immunity and are characterized by the production of IL-2 and IFN-y, whereas Th2 cells are more efficient in mediating antibody production and secrete II-4, IL-5, IL-6 and II-10, Thl cells can control Th2 cell and vice versa. Peripheral blood mononuclear cells of healthy, cured and chronic refractory tuberculosis patients were stimulated with PPD, TSP and PHA antigen, and lymphoproliferative response and expression of II-2, IL- 10, TNF-α mRNAs were measured. Lymphoproliferative responses to PPD, TSP and PHA antigen were depressed in chronic refractory case compared with others expression of IL-2 mRNA was depressed in chronic refractory case stimulated with all antigens. Expression of IL-10 and TNF-α were depressed in cured and chronic refractory cases stimulated with PPD and TSP antigens.

Streptozotocin 유도 당뇨쥐에서의 Phospholipase A₂, Cyclooxygenase 활성과 Thromboxane 및 Prostacyclin합성

양정아,김성옥,최정화,곽오계,이순재,장현욱 영남대학교 약품개발연구소 1998 영남대학교 약품개발연구소 연구업적집 Vol.8 No.-

당뇨병에서의 혈전생성 기전에 관련된 주된 요인을 관찰코져 흰쥐를 4주간 사육한 후 streptozotocin(STZ)으로 당뇨를 유발한 후 6일째에 희생하여 당뇨쥐에 있어서의 phospholipase A₂ 활성변화에 따른 조직의 과산화적 손상과 혈소판 응집능 등의 변화를 관찰한 결과는 다음과 같다. 체중증가는 STZ를 투여한 후에는 STZ 투여군에서 현저하게 감소하였다. 식이섭취에 있어 STZ injection 후, DM군은 16% 증가하였다. 식이효율은 STZ injection 후 DM군은 정상군에 비해 유의적으로 감소하였다. 혈청 중의 총 지질과산화물가는 정상군에 비해 DM군은 2.5배 높았다. HDL 중의 TBARS는 정상군에 비해 DM군은 약 1.6배 정도 높았고 LDL 중의 TBARS는 정상군에 비해 DM군에서 4.8배의 높은 증가를 보였다. 혈소판 phospholipase A₂ 활성은 DM군은 정상군에 비해 42% 증가하였다. 혈소판 cyclooxygenase 활성은 정상군에 비해 DM군이 2배 정도 높은 수준이었다. 혈소판 중의 TXA₂ 농도는 정상군과 비교하여 DM군에서 169%로 현저하게 높았고 대동백 PGI₂의 농도는 정상군에 비해 DM군은 낮은 수준을 보였으며 대동맥 PGI₂와 혈소판 TXA₂의 비는 DM군에서 정상군에 비해 55% 낮았다. 결론적으로 STZ 유발 당뇨쥐에 있어서는 혈청 지질과산화물 수준의 증가와 더불어 phospholipase A₂ 활성이 증가되었으며 따라서 cyclooxygenase가 유도하는 AA cascade 활성화에 의해 TXA₂ 생성증가 및 PGI₂/TXA₂ ratio의 감소가 관찰되었다. 이러한 결과는 당뇨병 질환에서 나타나는 동맥경화증, 심혈관계 질환 등의 여러 혈관계의 병리적 현상들이 당뇨 상태에서의 지질대사 이상으로 인한 지질과산화물의 증가와 그의 독성으로 인한 여러 혈소판 관련 인자들의 활성화와 밀접하게 연관되어 나타나는 것을 시사하는 것이라 하겠다. The relation between lipid peroxidation and thrombotic reaction were investigated in streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley male rats weighing 100±10gm were randomly assigned to normal and STZ-induced diabetic group(DM). Diabetes was experimentally induced by intravenous injection of 55mg/kg of body weight of STZ in citrate buffer(pH 4.3) after 4 weeks feeding of basal diet. Animals were sacrificed at the 6th day of diabetic states. Body weight gains were lower in diabetic group after STZ injection. Serum levels of thiobarbituric acid reacting substances(TBARS) that were markedly increased in DM group compared with of normal group. TBARS levles of HDL and LDL were similar patterns to total TBARS of serum. Activities of platelet phospholipase A₂(PLA₂) were higher in diabetic group than those of normal group. Activities of platelet cyclooxygenase were 106% in DM group than normal group. Platelet thromboxane A₂(TXA₂) formation was increased in DM group than normal group. Production of aortic prostacyclin(PGI₂) was lower in diabetic group than that of normal group. PGI₂/TXA₂ ratios were decreased by 55% in DM groups than those of normal group. The present results indicate that STZ-induced diabetic rats are more sensitive to oxidative stess which leads to acceleration of lipid peroxidation and platelet aggregability. In conclusion, accelerating effect of lipid peroxidation and thrombogenesis in diabetic state is regarded to be resulted from enhancement of PLA₂ activity and arachidonic acid metabolism, inhibition of antiaggregating agent and aortic PGI₂ formation.

광양만 광역도시계획 권역 교통수요예측에 관한 연구

오재화,정영덕 朝鮮大學校 建設技術硏究所 2006 建設技術硏究 Vol.26 No.1

Although there have been systemic efforts of the government to solve the metropolitan transportation problems, demand and supply for transportation facilities are not matched, yet. Scenario analysis by integrating land use and transportation has been popular in developed countries as a tool of metropolitan transportation policy making, and it can be adaptable in the metropolitan areas. Purpose of the study is to develope a model to help policy decision making for metropolitan transportation by setting policy scenarios of land use and transportation integration.

결핵군 55 kDa 항원의 면역학적 분석

김화중,김홍성,임재현,조은경,송창화,박정규 충남대학교 의과대학 지역사회의학연구소 1999 충남의대잡지 Vol.26 No.1

Identification and characterization of mycobacterial antigens are critical for evaluation of their role in diagnosis, vaccination, and pathogenesis of mycobacterial diseases. An attempt has been made to immunologic characterize the 55 kDa protein antigen of Mycobacterium tuberculosis H37Rv which attracted our interest because it is present in high concentration in 50-80% ammonium sulfate fraction of the culture filtrate. Two monoclonal antibodies (MAbs) directed to 55 kDa antigen were produced. MAbs MT55-1 and MT55-2 reacted with a single 55 kDa protein band. On examination of degree for cross-reactivity with other mycobacterial species by enzymelinked immunosorbent assay (ELISA) and immunoblotting, these antibodies reacted strongly with M. tuberculosis and M. bovis BCG, and reacted weakly with M. marinum and M. smegmatis. To investigated the subcellular distribution of MAbs defined epitopes in the 55 kDa antigen within the mycobacterium, we isolated three major subcellular factions of M. tuberculosis, namely, cell wall, cytoplasmic membrane, and cytosol, by a simple fractionation procedure. MAb MT55-1 reactive cpitope was found in the cytosol when tested by immunoblotting. A sandwich ELISA was initially developed for detecting 55 kDa antigen using MT55-1 MAb in mycobacterial culture filtrate before detecting it in clincal specimens. The minimal detectable concentration was 1.0 ㎍/m1 for M. tuberculosis culture filtrate and 100 ㎍/ml for sonic extracts of M. bovis BCG and M. marinum, respectively. But the 55 kDa antigen was not detected in sonic extracts of other mycobacterial species examined. Although further evaluations are required, this study suggests that the 55 kDa antigen may be of interest as potential diagnostic reagent.