50세 이상 남성의 식품 및 영양소 섭취실태와 골밀도와의 관계

김지명(Kim Ji-Myung),진미란(Jin Mi Ran),김혜원(Kim Hye Won),장남수(Chang Namsoo) 韓國營養學會 2011 Journal of Nutrition and Health Vol.44 No.5

Osteoporosis is a rising problem as the older age population is increasing due to prolongation of life. Genetic and environmental factors play key roles in bone metabolism and diet is also an important factor. We investigated the relationship among factors affecting bone mineral density (BMD) including daily food intake and nutrient intake in men aged >50 years. Seventy-eight men who visited the health promotion center at one of the university medical centers were divided into normal and osteopenia groups according to their BMD. The body weight of the normal group was significantly higher than that of the osteopenia group. The osteopenia group showed significantly higher carbohydrate intake and lower calcium and vegetable calcium intake compared to those in the normal group. Lumbar spine BMD was negatively correlated with energy fat vitamin B1 and sodium intake in the normal group. Additionally femoral neck BMD was negatively correlated with total animal protein energy protein fat phosphorous iron animal iron potassium vitamin B1 B2 B6 and niacin intake. Lumbar spine BMD was positively correlated with fruit calcium vegetable calcium animal calcium and vitamin C intake in the osteopenia group. Femoral neck BMD was negatively correlated with meat dairy product total animal protein plant protein animal protein vitamin A and cholesterol intake. A stepwise multiple regression analysis revealed that several dietary factors affected BMD including energy fat vitamin B1 B2 B6 niacin sodium protein iron animal iron phosphorous potassium and animal protein in the normal group and zinc calcium vegetable calcium animal calcium vitamin C fruit protein animal protein meat dairy product carbohydrates cholesterol vegetables mushrooms and seasonings in the osteopenia group. These results indicate that adequate nutrient intake plays an important role maintaining optimum bone health in middle aged men.

5kV급 MV-LVDC 독립형 마이크로그리드의 사고해석 모델링에 관한 연구

김지명(Ji-Myung Kim),한병길(Byeong-Gill Han),이후동(Hu-Dong Lee),김순식(Soon-Sik Kim),손만석(Man-Seok Son),노대석(Dae-Seok Rho) 대한전기학회 2021 대한전기학회 학술대회 논문집 Vol.2021 No.4

제5기 국민건강영양조사 자료를 이용한 중산층 성인의 영양소 섭취실태 연구

김지명(Kim, Ji-Myung),김혜숙(Kim, Hye Sook),김기남(Kim, Ki Nam) 한국영양학회 2015 Journal of Nutrition and Health Vol.48 No.4

본 연구는 중산층 성인 남녀의 영양상태를 저소득층 및 고소득층과 비교하기 위하여 실시되었으며, 다음과 같은 결과를 얻었다. 1. 대부분의 영양소 섭취량은 소득 수준에 따라 유의적인 차이가 있었으며, 특히, 에너지, 단백질, 지방, 칼슘, 인, 칼륨, 티아민, 나이아신, 비타민 C섭취 수준은 남녀 모두에서 소득 수준이 높을수록 섭취 수준이 높은 것으로 나타났다. 2. 철분과 리보플라빈 섭취량은 성별에 따라 다른 양상을 보였는데, 중산층 남성의 경우 철분과 리보플라빈 섭취 수준이 저소득층 보다 높고 고소득층과 유의적인 차이를 나타내지 않은 반면, 중산층 여성의 철분 섭취량은 고소득층 보다 낮고 저소득층과 유의적인 차이를 보이지 않았다. 3. 1,000 kcal 당 영양소 섭취 수준을 비교한 결과, 중산층 남성의 경우 탄수화물, 단백질, 지방의 섭취량은 고소득층과 유사하게 나타난 반면, 중산층 여성의 경우 이들 영양소 섭취량이 저소득층 보다 높고 고소득층 보다 유의적인으로 낮았다. 이상의 결과는 저소득층 뿐만 아니라 중산층, 특히 중산층 여성에 대한 영양문제에 관심을 가질 필요가 있다는 것을 보여준 것으로, 향후 소득 계층별 영양정책 수립에 있어, 성별에 대한 차이를 고려한 맞춤 복지에 대한 기초 자료로 활용될 수 있을 것으로 사료된다. Purpose: This study was conducted to evaluate nutritional status in middle-class adults compared with low income or high income adults according to gender difference. Methods: Data from the 2012 Korea National Health and Nutrition Examination Survey was used. A total of 7,082 adults aged from 30 to 64 were included and classified according to household income level into three groups. Dietary data was collected using 24-hr recall methods. Results: Most nutrients including energy, protein, vitamins, and minerals such as iron and calcium differed according to income levels. Iron intake of middle-class men was higher than that of the lowest income group, whereas that of middle-class women was similar to that of the lowest income group. In addition, no significant difference in carbohydrate, protein, fat, thiamin, and niacin intakes per 1,000 kcal and iron intake was found between the middle and high income group only in male subjects. In summary, our results showed that the relationship between nutritional status and income level as a socioeconomic parameter could vary according to gender difference. Conclusion: According to our results, it could be suggested that not only the lowest income people but also middle class women should be concerned in development of nutritional policies. Gender difference should be considered. It is a very meaningful implication for application to policy for obesity prevention or intervention.

PSCAD/EMTDC를 이용한 ESS의 누설전류 모델링에 관한 연구

김지명(Ji-Myung Kim),태동현(Dong-Hyun Tae),이일무(Il-Moo Lee),임건표(Geon-Pyo Lim),노대석(Dae-Seok Rho) 한국산학기술학회 2021 한국산학기술학회논문지 Vol.22 No.2

ESS의 누설전류는 PCS(Power Control System)측 누설전류와 계통불평형 전류로 인한 누설전류로 구분되는데, PCS측의 누설전류는 정상 상태 운전 시, IGBT(Insulated Gate Bipolar Transistor) 스위칭의 전압 변화량과 IGBT와 방열판 사이에 존재하는 기생 커패시턴스에 의해 발생한다. 또한, 계통불평형 전류에 의한 누설전류는 불평형 부하로 인해 발생한 불평형 전류가 Yg-Δ 결선방식의 3각 철심이 적용된 태양광전원 연계형 변압기의 중성선을 통해 ESS로 유입된다. 따라서, 본 논문에서는 방열판 유도공식을 통해 산정한 기생 커패시턴스에 의하여 PCS측의 누설전류 발생메커니즘을 제시하고 또한, 계통불평형에 의한 ESS측의 누설전류 발생 메커니즘을 제안한다. 이를 바탕으로, 배전계통 상용해석 프로그램인 PSCAD/EMTDC를 이용하여 배터리부, PCS부, AC전원부로 이루어진 PCS측의 누설전류 발생 메커니즘과 배전 계통부, 불평형 부하부, ESS부로 이루어진 계통불평형에 의한 ESS측의 누설전류 발생 메커니즘을 모델링하고, 누설전류의 특성을 평가한다. 상기의 모델링을 바탕으로 시뮬레이션을 수행한 결과, 외함의 저항과 접지저항의 크기에 따라 PCS측의 누설전류는 7[mA]에서 34[mA]로, 계통불평형에 의한 배터리 외함으로 흐르는 누설전류는 3.96[mA]에서 10.76[mA]로 증가하여 배터리측에 큰 영향을 미침을 알 수 있었다. A leakage current of ESS is classified mainly by the occurrence from a PCS(Power Conditioning System) section and an unbalanced grid current. The reason for the leakage current from the PCS section is a voltage change by IGBT (Insulated Gate Bipolar Transistor) switching and stray capacitance between the IGBT and heatsink. The leakage current caused by the grid unbalanced current flows to the ESS through the neutral line of grid-connected transformer for the ESS with a three limb iron type of Yg-wire connection. This paper proposes a mechanism for the occurrence of leakage current caused by stray capacitance, which is calculated using the heatsink formula, from the aspect of the PCS section and grid unbalance current. Based on the proposed mechanisms, this study presents the modeling of the leakage current occurrence using PSCAD/EMTDC S/W and evaluates the characteristics of leakage currents from the PCS section and grid unbalanced current. From the simulation result, the leakage current has a large influence on the battery side by confirming that the leakage current from the PCS is increased from 7[mA] to 34[mA], and the leakage current from an unbalanced load to battery housing is increased from 3.96[mA] to 10.76[mA] according to the resistance of the housings and the magnitude of the ground resistance.

결혼이주여성의 식생활 적응 및 영양소 섭취실태

김지명(Kim Ji-Myung),이희승(Lee Hee Seung),김민화(Kim Min Hwa) 韓國營養學會 2012 Journal of Nutrition and Health Vol.45 No.2

The purpose of this study was to investigate Korean food adaption, eating behavior and dietary intakes of married female immigrants by age, number of residence years in Korea and level of income. The survey included 67 female marriage immigrants attending the Korean language class at the multicultural family support center within the northern part of Kyonggi province from October 2010 to July 2011. General characteristics, Korean dietary life adaptation, and eating behavior were collected and dietary intakes were assessed using 24-hour recall. The home countries with regards to all subjects were Vietnam (40.3%), China (23.9%), Japan (11.9%), Philippines (7.0%), and Mongolia (3.0%). Total energy intake was 1432.5kcal and there were significant differences in nutritional intake concerning vitamin B1 and vitamin B2 by age (p < 0.05). More than 50% of subjects did not meet estimated average requirements for calcium (56.7%), zinc (52.2%), vitamin C (55.2%), and folic acid (76.1%). Food adaptation scores were significantly correlated with general characteristics (age, residence year, drinking alcohol and acquisition of nationality), total scores of eating behavior, and nutritional intake (energy, protein, fat, fiber, calcium, phosphorus, sodium, potassium, niacin, vitamin E, and zinc). These results might suggest that the better their Korean food adaptation, the more desirable their eating behavior and nutritional status. (Korean J Nutr 2012; 45(2): 159 ~ 169)

ESS 연계용변압기의 결상사고 검출 알고리즘에 관한 연구

김지명(Ji-Myung Kim),김경화(Kyung-Hwa Kim),남양현,김기영,노대석(Dae-Seok Rho),Min-Gyu Lim,Jae-Beom Jung 대한전기학회 2022 대한전기학회 학술대회 논문집 Vol.2022 No.7

5㎸급 MV-LVDC 독립형 마이크로그리드의 사고 해석 모델링에 관한 연구

김지명(Ji-Myung Kim),이후동(Hu-Dong Lee),태동현(Dong-Hyun Tae),노대석(Dae-Seok Rho) 한국산학기술학회 2021 한국산학기술학회논문지 Vol.22 No.9

최근, 전 세계적으로 신재생에너지전원의 도입, DC 부하의 증가 그리고 소비자의 고품질·고신뢰성 전력 요구로 인하여, MVDC 배전계통에 대한 필요성이 급증하고 있지만, MVDC용 기기들의 상용화는 아직 초기단계에 머물러 있는 실정이다. 이에 따라, 기존에 사용되고 있는 AC용 기기 및 선로를 이용하여 MVDC 배전망에 적용하기 위한 실증 연구가 진행되고 있지만, 기존의 AC용 기기들을 사용할 경우, 컨버터 및 선로와 같은 고가의 설비들은 사고 발생 시 안정적으로 보호하지 못할 가능성이 있으므로, MVDC 배전망의 안정적인 운용을 위한 사고특성의 해석이 요구되고 있다. 따라서, 본 논문에서는 5kV급 MV-LVDC 마이크로그리드의 사고지점별 전류의 특성을 해석하기 위해, 배전계통 상용해석 프로그램인 PSCAD/EMTDC를 이용하여, 태양광전원, ESS, MVDC 선로, DC/DC 컨버터, DC/AC 인버터, 등으로 구성된 MV-LVDC 마이크로그리드의 전체 시스템의 모델링을 수행한다. 이를 바탕으로 다양한 사고지점별 시뮬레이션을 수행한 결과, MVDC 선로, LVDC 선로, AC 선로에서의 사고전류 특성은 사고의 위치, 사고 전류를 공급하는 전원의 종류, 각종 전력변환기기, 등에 영향을 받아 각 특성에 맞는 보호협조의 설계가 필요함을 알 수 있었다. The MVDC distribution system has recently been in demand due to the interconnection of renewable energy sources, increase in DC load, and customer’s demands for a high quality and reliable power system, while the commercialization of devices for MVDC is in the early stages. Accordingly, demonstration projects on applying existing AC devices and cables to MVDC distribution systems are being carried out. On the other hand, the protection of high-cost facilities, such as converters and cables, using existing AC devices and cables, may not be reliable in the event of a fault, and an analysis of the fault characteristics is required for the stable operation of an MV-LVDC microgrid (MG) system. This paper proposes the modeling of 5kV MV-LVDC MG system, which is composed of a PV system, ESS, MVDC cable, DC/DC converter, and DC/AC inverter using PSCAD/EMTDC S/W, to analyze the characteristics of the fault current at each fault location in the MV-LVDC MG system. The simulation results based on proposed modeling showed that a consideration of the fault current at each fault location is necessary to design protection coordination in an MV-LVDC MG system because the characteristics of the fault current in the MVDC cable, LVDC cable, and AC cable may vary depending on the fault location, types of power source, and power conversion types.

5kV급 MV-LVDC 독립형 마이크로그리드의 보호협조 운용방안에 관한 연구

김지명(Ji-Myung Kim),이후동(Hu-Dong Lee),한병길(Byeong-Gill Han),노대석(Dae-Seok Rho) 대한전기학회 2022 전기학회논문지 Vol.71 No.1

Recently, demands on MVDC distribution system is being significantly increased due to interconnection of renewable energy sources, expansion of DC load and high quality and reliability of the power supply system etc., while commercialization of facilities for MVDC is yet in early stage. Accordingly, demonstration projects on applying existing AC devices and cables to MVDC distribution system are being carried out. However, the protection on high-cost facilities such as converters and cables may not be reliable in the event of fault, and then operation method of protection coordination for MV-LVDC micro grid(MG) system is being required. For the purpose of stable operation of the 5kV MV-LVDC micro-grid, this paper proposes operation methods of protection devices depending on scenarios, such as faults on the MVDC line, LVDC line, or customer load. And also, a modeling of 5kV MV-LVDC MG system, which is composed of PV system, ESS, MVDC cable, DC/DC converter, DC/AC inverter, protection devices etc., is performed using PSCAD/EMTDC S/W. From the simulation results based on the proposed modeling and operation method of protection devices, it is confirmed that this paper is useful tool to perform the proper protection coordination.

RPN 방식에 따른 운용환경을 고려한 ESS의 안전성 평가에 관한 연구

김지명(Ji-Myung Kim),한병길(Byeong-Gill Han),이민행(Min-Haeng Lee),이근형(Keun Hyung Lee),노대석(Dae-Seok Rho) 대한전기학회 2023 대한전기학회 학술대회 논문집 Vol.2023 No.7

기생 커패시턴스 및 접지저항을 고려한 ESS의 누설전류 특성에 관한 연구

김지명(Ji-Myung Kim),김윤호(Yun-Ho-Kim),조성덕(Sung-Duck Cho),한병길(Byeong-Gill Han),노대석(Dae-Seok Rho) 대한전기학회 2022 대한전기학회 학술대회 논문집 Vol.2022 No.10