• 대한전자공학회논문지SD
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• 제48권7호
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• pp.1-9
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• 2011

멤리스터(Memristor)는 메모리 레지스터의 합성어로 흐른 전하량에 따라 저항이 스스로 변하고 전원이 끊긴 상태에서도 저항 상태가 기억되는 특수한 메모리 소자이다. 본 논문에서는 차세대 메모리소자로 주목받고 있는 멤리스터를 모델링하고 SPICE 시뮬레이션을 위한 behavior모델을 제시한다. 그리고 제안된 모델을 바탕으로 멤리스터 기반의 M_CAM(Memristor MOS content addressable memory)을 설계하였다. 제안된 M_CAM은 기존의 CAM에 비해서 단위 셀 면적과 평균 전력소모가 각각 40%, 96% 감소하였다. 칩은 0.13${\mu}m$ CMOS 공정에서 공급전압이 1.2V를 갖도록 설계되었다.

• 한국주거학회논문집
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• 제20권4호
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• pp.69-78
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• 2009

The purpose of this study is to identify which is the better indicator to forcast housing tenureship between permanent income and current income, and study the effects of non-human capital asset on housing tenureship. To forcast permanent income, a statistic regression equation is used with current income as the dependent variable. Multi-nomial logistic model is used to forcast the housing tenureship Using current income as the dependent variable delivered a more accurate result than using permanent income. Current income is used as a dependent variable and sex, age, education and occupation are used as independent variables to forcast permanent income. Non-human capital asset is also used as an independent variable. Also, excluding non-human capital asset variable when forcasting bothe permanent income and housing tenureship proved to be more accurate. Because permanent income, the sum of future income and current asset, is a good indicator of current consumption including housing, the result with permanent income should be more accurate than the forcast using current income. This implies an underdevelopment of a housing mortgage system that enables people to consume now on the basis of their future income. The Korea's unique Chonsei housing rental system has also made it difficult to forcast housing tenureship based on people's permanent income and asset. While, the Key-money of Chonsei housing and the housing asset of homeowners with debt are very similar in their amount, the result is completely different. One is a renter and the other is a homeowner.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권1호
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• pp.27-31
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• 2000

Characteristics of ethanol production by a xylose-fermenting yeast, Pichia stipitis Y-7124, were studied. The sugar consumption rate and specific growth rate were higher in the glucose-containing medium than in the xylose-containing medium. Specific activities of xylose reductase and xylitol dehydrogenase were higher in the medium with xylose than glucose, suggesting their induction by xylose. Maximum specific growth rate and ethanol yield were achieved at 30 g xylose/L concentration without formation of by-products such as xylitol and acetic acid whereas a maximum ethanol concentration was obtained at 130 g/L xylose. Adding a respiratory inhibitor, rotenone, increased a maximum ethanol concentration by $10\%$ compared with the control experiment. In order to evaluate the pattern of ethanol inhibition on specific growth rate, a kinetic model based on Luong's equations was applied. The relationship between ethanol concentration and specific growth rate was hyperbolic for glucose and parabolic for xylose. A maximum ethanol concentration at which cells did not grow was 33.6 g/L for glucose and 44.7 g/L for xylose.

• Asian Pacific Journal of Cancer Prevention
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• 제17권4호
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• pp.2007-2017
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• 2016

Background: Modifying lifestyle factors such as diet and exercise can reduce the risk of cancer. Psychological stress (PS) might be indirectly associated with cancer because it alters lifestyle factors. However, the relationship among these variables has not been fully investigated. Thus, we examined interactions between self-reported PS (SRPS) and habitual exercise on diet. Materials and Methods: In all, 5,587 men and 2,718 women were divided into "exerciser" and :non-exerciser" groips, based on whether they exercised reguarly, and classified into three SRPS levels: low, moderate and high. Diet was estimated using a validated food frequency questionnaire. Using a general linear model, food and nutrient consumption was estimated for each SRPS level in the 2 exercise groups, and the interactions between SRPS levels and exercise were calculated. Results: In women, the intake of pork and beef, low fat milk and yogurt, natto (fermented soybean), carrots and squash, other root vegetables, mushrooms, seaweeds, and wine along with the nutrients vegetable protein, soluble, insoluble and total dietary fiber, daidzein, genistein, carotene, retinol equivalents, vitamin B2, pantothenic acid, potassium, calcium, magnesium, phosphorus and iron demonstrated significant interaction with SRPS and habitual exercise (p for interaction <0.05). In men, raw and green leafy vegetable and fruit and vegetable juice significantly interacted with SRPS and habitual exercise (p for interaction <0.05). Conclusions: We suggest that certain foods and nutrients, which are thought to have a protective effect against cancer, interact with SRPS and habitual exercise, especially in women. This information is valuable for understanding and improving interventions for cancer prevention.

• 한국수산과학회지
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• 제25권6호
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• pp.511-519
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• 1992

식품의 가열살균공정에 있어서 자동화는 에너지 소비의 성력화와 품질과의 관계 최적화를 위한 필수조건 중의 하나이다. 이를 위하여 마이크로컴퓨터를 이음한 자동화 시스템을 개발하였다. 시스템의 성능 및 정확도는 고형식품으로 사용한 명태 고기풀의 가열살균과정에서의 열침투곡선과 열확산도의 정확도로써 검토하였다. 자동화 시스템을 이용하여 측정한 명태 고기풀의 열침투곡선은 전형적인 고형식품의 열침투곡선을 나타내었다. 열침투곡선으로 부터 계산된 열확산도의 경우, 일정 살균온도에서는 다른 조건의 변화에 관계없이 일정한 값을 나타내었다. 가열살균온도를 변화시켜 구한 열확산도를 문헌상에 보고된 열확산도 추정식으로 구한 값과 비교하였을 때, 큰 차이를 보이지 않았으며 그 차이는 $\pm10.0\%$이내였다.

• Nutrition Research and Practice
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• 제14권1호
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• pp.62-69
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• 2020

BACKGROUND/OBJECTIVES: A number of studies examined secular trends in blood lipid profiles using time series data of national surveys whereas few studies investigated individual-level factors contributing to such trends. The present study aimed to examine secular trends in dietary and modifiable factors and hyper-LDL-cholesterolemia (HC) prevalence and evaluate their associations using time series data of nationwide surveys. SUBJECTS/METHODS: The study included 41,073 Korean adults aged ≥ 30 years from the 2005, 2007-2009, 2010-2012, 2013-2015, and 2016 Korea National Health and Nutrition Examination Surveys. Stepwise logistic regression analysis was performed to select significant factors associated with HC, which was defined as serum LDL cholesterol levels ≥130 mg/dL. RESULTS: The following factors showed a positive association with HC (P < 0.05): for men having higher body mass index (BMI), being married, having an office job, and consuming higher dairy and vegetable oil products; for women having higher age or BMI, having no job or a non-office job, not in a low-income household, and consuming higher dairy products. In the given model, the 2016 survey data showed that a 2 kg/㎡ reduction in BMI of obese persons resulted in a decreased HC prevalence from 30.8% to 29.3% among men and from 33.6% to 32.5% among women. CONCLUSIONS: Based on these findings, it is suggested that primary prevention programs should advocate having proper BMI for Korean adults with a high-risk of HC. However, whether discouraging consumption of dairy and vegetable oil products can reduce HC prevalence warrants further studies with a prospective longitudinal design.

• 한국정보시스템학회지:정보시스템연구
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• 제26권3호
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• pp.295-312
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• 2017

Purpose Consumption behaviors of consumers have changed with the widespread use of the Internet and smart phones, and accordingly online marketing activities are becoming ever more prevalent. Yet, the domestic food-service industry has yet to offer an Omni-Channel order system that encompasses a online, offline, and mobile interface. Also, a multilingual menu ordering service for foreign tourists is not yet available. Therefore, if an order service system accessible online and offline which could provide multi-language services were implemented, the satisfaction of the service provider and domestic and foreign customers would be maximized. Design/methodology/approach By designing an electronic menu based on open an OS and providing electronic menus in offline stores, we have completed the design of a linked order system which would be available everywhere (online, offline, and mobile). The CMS was developed to integrate these three mediums and the entire operator was designed to receive basic information and statistical information about the merchants, or store operators. Also, a multilingual term dictionary containing menu information for foreign tourists was made into a database so that foreign tourists who are having difficulty in communication can use it more easily. Findings We have made it possible for customers to use the order service without distinction between online, offline, and mobile platforms, and have proved that it is a more efficient and convenient service for customers as well as operators. Nevertheless, as an initial model, the implemented system has limitations on the execution of the payment support method in the electronic menu board and in the management division of the CMS. In case of commercialization, it is necessary to make an alliance of efforts to attract initial franchises. Through further supplementation, we expect the online and offline connection-types martservice system will maximize the satisfaction of both operators and customers alike.

• 대한기계학회논문집B
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• 제30권6호
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• pp.553-559
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• 2006

Most diesel injector, which is currently used in high-pressure common rail fuel injection system of diesel engine, is driven by the solenoid coil energy for its needle movement. The main disadvantage of this solenoid-driven injector is a high power consumption, high power loss through solenoid coil and relatively fixed needle response's problem. In this study, a prototype piezo-driven injector, as a new injector mechanism driven by piezoelectric energy based on the concept of inverse piezo-electric effect, has been designed and fabricated to know the effect of piezo-driven injection processes on the diesel spray structure and internal nozzle flow. Firstly we investigated the spray characteristics in a constant volume chamber pressurized by nitrogen gas using the back diffusion light illumination method for high-speed temporal photography and also analyzed the inside nozzle flow by a fully transient simulation with cavitation model using VOF(volume of fraction) method. The numerical calculation has been performed to simulate the cavitating flow of 3-dimensional real size single hole nozzle along the injection duration. Results were compared between a conventional solenoid-driven injector and piezo-driven injector, both equipped with the same micro-sac multi-hole injection nozzle. The experimental results show that the piezo-driven injector has short injection delay and a faster spray development and produces higher injection velocity than the solenoid-driven injector. And the predicted simulation results with the degree of cavitation's generation inside nozzle for faster needle response In a piezo-driven injector were reflected to spray development in agreement with the experimental spray images.

• 노동경제논집
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• 제25권2호
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• pp.33-78
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• 2002

본 논문은 법정근로시간 단축에 대한 이론적 및 실증적 효과를 분석한다. 법정근로시간 단축은 이론적으로 임금소득을 상승시키며 소비를 촉진하는 효과가 있는 반면 실근로시간은 약간 줄어들거나 정체하며 비용 상승이 클 경우 고용이 감소하는 효과를 일으킨다. 거시모형을 통한 실증분석은 법정근로시간 단축으로 실질임금이 상승하고 소비가 증대하는 반면 실근로시간의 단축은 법정근로시간 단축 크기의 절반 정도에 그치고 비용 인상 인플레이션이 일어나 GDP와 투자가 감소하는 결과를 낳는 것으로 나타났다. 그리고 법정근로시간 단축이 단계적으로 시행될수록, 그리고 월차휴가, 생리휴가 폐지와 같은 보완장치가 더불어 시행될수록 이 같은 부정적인 효과는 줄어드는 것으로 나타났다.

• Journal of Astronomy and Space Sciences
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• 제13권2호
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• pp.105-116
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• 1996

이 연구는 1992년 8월 11일과 1993년 9월 26일 발사된 우리별 1호 및 우리별 2호의 열제어 모델 및 그 동안의 운용 결과에 대한 해석을 바탕으로 한 것이다. 우리별 1, 2호는 아리안 발사체의 초소형 위성 탑재를 위한 특수 구조물에 장착되어 발사되었기 때문에 크기, 전력, 무게 등의 제한으로 인해 외부로부터의 열 흡수와 방출의 제어 및 내부의 연결 모듈간의 열 흐름을 제어하여 위성체 전반의 열적 환경을 조절하는 수동적인 방식의 열제어를 채택하게 되었다. 우리별 위성의 주 임무는 위성 기술의 개발과 더불어 위성체 바닥면에 탑재된 CCD 카메라를 이용하여 지구 표면을 촬영하는 것이었기 때문에 위성의 바닥면은 항상 지구의 중심을 향하고 있게 된다. 이 연구는 위성의 임무 궤도에 대한 분석으로부터 열 모델링, 시뮬레이션 결과 및 우리별 2호의 실제 운용헤서 얻어진 원격검침 정보를 바탕으로 한 열 모델의 평가를 포함한다. 이 분석 결과를 바탕으로 수동 제어에 의한 우리별 위성의 열 모델 및 해석이 실제 측정된 온도 데이터와 평균 오차 $$10^{\circ}C$ 이내에서 일치되었음을 보여 준다.