• Composites Research
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• 제29권4호
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• pp.179-185
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• 2016

A self-charging supercapacitor is constructed through simple integration of the energy storage and photo exited materials at the photo electrode. The large band gap of $NiO/Fe_3O_4$ heterostructure generates photo electron at the photo electrode and store the charges through redox mechanism at the counter electrode. Sulfanilic acid azocromotrop/reduced graphene oxide layer at the photo electrode trapped the photo generated hole and store the charge by forming double layer. The solar supercapacitor device is charged within 400 s up to 0.5 V and exhibited a high specific capacitance of ~908 F/g against 1.5 A/g load. The solar illuminated supercapacitor shows a high energy and power density of 33.4 Wh/kg and 385 W/kg along with a very low relaxation time of ~15 ms ensuring the utility of the self charging device in the various field of energy storage and optoelectronic application.

• The Korean Journal of Physiology and Pharmacology
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• 제6권2호
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• pp.93-99
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• 2002

Effects of oxidized low-density lipoprotein (ox-LDL), $1-{\alpha}-stearoyl-lysophosphatidylcholine$ (LPC), on intracellular $Ca^{2+}$ concentration were examined in mouse endothelial cells by measuring intracellular $Ca^{2+}$ concentration $([Ca^{2+}]_i)$ with fura 2-AM and reverse transcription-polymerase chain reaction (RT-PCR). LPC increased $[Ca^{2+}]_i$ under the condition of 1.5 mM $[Ca^{2+}]_o$ but did not show any effect under the nominally $Ca^{2+}-free$ condition. Even after the store depletion with $30{\mu}M$ 2,5-di-tert- butylhydroquinone (BHQ) or $30{\mu}M$ ATP, LPC could still increase the $[Ca^{2+}]_i$ under the condition of 1.5 mM $[Ca^{2+}]_o.$ The time required to increase [$Ca{2+}$]i (about 1 minute) was longer than that for ATP-induced $[Ca^{2+}]_i$ increase $(10{\sim}30\;seconds).$ LPC-induced $[Ca^{2+}]_i$ increase was completely blocked by $1{\mu}M\;La^{3+}.$ Transient receptor potential channel(trpc) 4 mRNA was detected with RT-PCR. From these results, we suggest that LPC increased $[Ca^{2+}]_i$ via the increase of $Ca^{2+}$ influx through the $Ca^{2+}$ routes which exist in the plasma membrane.

• Spatial Information Research
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• 제11권2호
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• pp.171-184
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• 2003

최근 마케팅이나 기업전략 수립분야에서 비지니스 GIS를 적용하기 위한 다양한 응용시스템이 개발되고 있다. 이 중 대부분이 의사결정지원을 위한 정보로서 지리공간상에서의 상권이라고 하는 특정 범위에 대한 통계정보의 산출을 요구한다. 기존에 상권범위의 정의는 대부분 개별점포에 대해 경험치를 적용하여 이루어져 왔으며, 특정업종이나 소비자 상권과 같은 일반적인 의미의 상권을 정의하는 객관적인 방법이 제시되지 않았다. 본 연구에서는 비지니스 GIS 분야에 축적된 점사상 정보에 공간 데이터마이닝 기법을 적용하여 상권의 범위를 추출할 때, 기법 간의 장단점을 비교분석하고, 상권추출의 타당성을 검증하고자 하였다. 본 연구의 결과 점사상으로 사용된 카드사 가맹점 데이터와 소매체인 회원의 정보를 이용하여 상권의 추출이 가능하며, DENCLUE(DENsity-based CLUstEring) 기법이 적합한 공간 데이터마이닝 기법임을 알 수 있었다.

• Nutrition Research and Practice
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• 제15권3호
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• pp.396-410
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• 2021

BACKGROUND/OBJECTIVES: High-quality meal intake, including snacks, is necessary for optimal development during adolescence. The purpose of this study was to evaluate the nutritional intake of adolescents and the quality of their diet according to snack type, eating location, and sleep hours. SUBJECTS/METHODS: A survey of middle school students living in Seoul and Gyeonggi province was conducted using questionnaires and the 24-h recall method to collect data on the 1-day dietary intake of the students from March to May, 2018. The data were analyzed using SPSS 23.0 and the CAN program. RESULTS: The average nutritional intake status among the respondents showed that the energy intake was lower than the recommended, showing 1,914.8 kcal for middle school boys and 1,752.7 kcal for girls. In terms of the nutritional intake status by gender, only the consumption of protein and niacin were significantly higher in boys than girls (P < 0.05). According to the sleep amounts, vitamin C intake was significantly higher in the sleep-deprived group than in the sleep-moderate or sleep-recommended group (P < 0.05), but the intake did not meet the recommendation in any group. The lower density nutrients found in the index of nutritional quality according to eating places were vitamin C, calcium, iron, and folic acid. School meals showed a higher nutritional density in protein, vitamin B₁, and niacin compared to convenience store meals (P < 0.05). CONCLUSIONS: This study suggested that sleep amount, and eating place affected the dietary quality of adolescents.

• 토지주택연구
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• 제15권1호
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• pp.57-75
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• 2024

활기 넘치는 거리를 만들기 위해서는 다양한 종류의 상업시설의 입지가 필요하다. 상업시설은 지역 유동인구 증가에 영향을 미치는 가장 중요한 요소이다. 따라서 상업시설의 다양성이 높을수록 소비 활성화에 기여할 것이라는 추론이 가능하다. 이와 관련하여 본 연구는 상업시설의 혼합이 소비중심지수에 미치는 영향을 알아보았다. 본 연구는 2021년을 시간적 범위로 설정하였으며, 공간적 범위는 서울시로 하였다. 커널밀도분석을 통하여 산출한 소비중심지수를 종속변수로 하고, 상업 특성을 반영한 요인과 도시 특성 등을 반영한 요인을 독립변수로 설정하여 분석을 진행하였다. 분석 방법은 공간회귀분석을 활용하였고 분석단위는 행정동으로 설정하였다. 분석을 통하여 이종업종의 집적보다 동종업종의 집적이 소비 활성화에 긍정적인 영향을 미치는 것을 확인하였다. 또한 소비 활성화에 긍정적인 영향을 미치는 업종들의 집적이 필요하다는 시사점을 확인하였다. 본 연구의 분석 결과는 소비시장에서 상업시설 입지 정책의 효율적인 관리에 시사점을 제공할 수 있을 것으로 기대된다.

• 항공우주시스템공학회지
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• 제18권3호
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• pp.8-16
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• 2024

수소는 매우 낮은 밀도를 갖기 때문에 화석연료와 동일한 수준의 에너지량을 저장하기 위해서는 기존과 다른 저장방식이 요구된다. 수소의 밀도를 높이는 방법으로는 수소를 액화하여 저장하는 방법이 있다. 하지만, 수소의 액화온도는 -252 ℃의 극저온이기 때문에 외부 열 유입에 의해 쉽게 기화된다. 액체수소가 기화되면 탱크 내부의 압력이 증가되는 자가증압 현상을 발생하므로, 탱크 설계 시 이 상승하는 압력을 잘 예측해야 한다. 따라서, 본 논문에서는 극저온 액체수소 연료탱크의 액체수소 충전 비율에 따른 내부 압력을 예측하였다. 탱크 내부의 압력 상승을 예측하기 위하여 1차원 열역학적 모델을 적용하였다. 열전달 모델은 열 유입, 액체수소의 기화, 연료 배출에 현상이 고려되었다. 최종적으로 연료탱크 내의 액체수소의 충전 비율에 따라 압력 상승 거동과 최대 상승 압력에 큰 차이가 있음을 확인하였다.

• 한국응급구조학회지
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• 제10권1호
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• pp.23-39
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• 2006

In Korea, There are many disasters, like the collapse of Sampung department store, the strike of severe typhoon 'Rusa' and the subway tragedy in Taegu, because of global warming, urbanization, high-density and high-rise of buildings. So, the government made 'The Framework Act' on the safe and management of disaster and 'The National Emergency Management Agency' was established. But emergency medical service systems in Korea is not growing so much. The purpose of this research is to give basic data for the development of emergency medical service systems in Disaster by comparing of disaster management systems and emergency medical systems among the nations of the world, analysing emergency medical systems in disaster in Korea and suggesting some improvement methods. The improvment methods are like this ; First, establishing the National Disaster Medical System in Korea, making the good triage by EMT, expansion of EMT's working area, developing protocols and framing of medical director increasing the working force of EMT, broad inner cavity of ambulance for treatment of patientent, supplement of professional equipments, active using of helicopters are needed in prehospital are. Second, equal establishment of emergency medical center and increase of working force of emergency medical team are needed in hospital area. Finally, enforcement of the dispatcher's qualification, smooth communication among EMSS systems and actualization of medical direction through screen are needed in the Telecommunication system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권8호
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• pp.2923-2943
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• 2021

The double helix structure of DNA makes it diverse, stable and can store information with high density, and these characteristics are consistent with the requirements of molecular communication for transport carriers. In this paper, a specific structure of molecular communication system based on DNA length coding is proposed. Transmitter (Tx) adopts the multi-layer golden foil design to control the release of DNA molecules of different lengths accurately, and receiver (Rx) adopts an effective and sensitive design of nanopore, and the biological information can be converted to the electric signal at Rx. The effect of some key factors, e.g., the length of time slot, transmission distance, the number of releasing molecules, the priori probability, on channel capacity is demonstrated exhaustively. Moreover, we also compare the transmission capacity of DNA-based molecular communication (DNA-MC) system and concentration-based molecular communication (MC) system under the same parameter setting, and the peak value of capacity of DNA-MC system can achieve 0.08 bps, while the capacity of MC system remains 0.025 bps. The simulation results show that DNA-MC system has obvious advantages over MC system in saving molecular resources and improving transmission stability.

• 전기학회논문지
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• 제62권1호
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• pp.63-69
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• 2013

In recent years, technology for storing a preliminary power or a surplus of photovoltaic energy is required. This technique, as well as store a preliminary energy and improve the reliability of the gird safety. This system can plan a efficient power generation through the flexibility of the power supply from the perspective of not only provider but also user. Accordingly, the realization of the smart grid can be expected. This paper proposes a hybrid PCS using a photovoltaic and a lithium-polymer battery with the characteristics of high density energy. The main energy source of a hybrid PCS is a photovoltaic, grid and the auxiliary energy source is a lithium-polymer battery. The operation of a proposed system in this paper is verified with simulation and experimental results.

• Bulletin of the Korean Chemical Society
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• 제33권3호
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• pp.855-861
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• 2012

A pioneering version of an on-line management system for high-energy molecules (MS-HEMs) was developed by the ADD and BMDRC in Korea. The current system can manage the physicochemical and explosive properties of virtual and existing HEMs. The on-line MS-HEMs consist of three main routines: management, calculation, and search. The management routine contains a user-friendly interface to store and manage molecular structures and other properties of the new HEMs. The calculation routine automatically calculates a number of compositional and topological molecular descriptors when a new HEM is stored in the MS-HEMs. Physical properties, such as the heat of formation and density, can also be calculated using group additivity methods. In addition, the calculation routine for the impact sensitivity can be used to obtain the safety nature of new HEMs. The impact sensitivity was estimated in a knowledge-based manner using in-house neural network code. The search routine enables general users to find an exact HEM and its properties by sketching a 2D chemical structure, or to retrieve HEMs and their properties by giving a range of properties. These on-line MS-HEMs are expected be powerful tool for deriving novel promising HEMs.