• Applied Biological Chemistry
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• 제49권2호
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• pp.103-107
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• 2006

비타민 정제 중의 지용성 비타민의 저장 습도 및 저장 온도에 따른 저장 안정성을 연구한 결과 개봉을 하지 않은 상태에서는 저장 온도에 상관없이 상당히 안정한 것으로 나타났다. 흥미로운 사실은 일부 지용성 비타민들이 개봉을 한 상태에서는 습도에 매우 민감하다는 사실이었는데, 지용성 비타민 중 분말형태로 제조하기 위하여 acetate form으로 존재하는 비타민 A acetate와 비타민 E acetate는 수분에 아주 민감하다는 사실을 확인할 수 있었다. 이들 지용성 비타민은 개봉을 한 상태에서는 습도에 매우 민감하여 그 손실 속도가 매우 빨라지는 경향을 나타내었다. 또한 비타민 정제의 경우 수분이 가소제로 작용하여 비타민 정제 중의 성분들의 mobility를 증진시킴으로써 비타민의 손실 속도가 빨라지는 것으로 판단된다. 따라서 이러한 결과로 볼 때 tablet형태의 복합 비타민제에 존재하는 지용성 비타민의 경우 저장 온도보다는 저장 습도에 유의를 하여야 할 것으로 판단된다.

• Journal of Pharmaceutical Investigation
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• 제41권2호
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• pp.103-109
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• 2011

The objective of the study was to prepare self-microeulsifying drug delivery system (SMEDDS) incorporating atorvastatin calcium and evaluate its properties and oral bioavailability. Solubility of atorvastatin in various vehicles was determined. Pseudo-ternary phase diagrams were constructed to identify the good self-emulsification region. The droplet size distributions of the resultant emulsions were determined by dynamic light scattering measurement. The mean droplet size of chosen formulation (20% ethyl oleate, 40% tween-80, 40% Carbitol$^{(R)}$) was $23.4{\pm}1.3$ nm. The SMEDDS incorporating atorvastatin calcium appeared to be associated with better performance in dissolution and pharmacokinetic studies, compared with raw atorvastatin calcium. In dissolution test, the release percentage of atorvastatin from SMEDDS mixture could rapidly reach more than 95% within 3 min. Oral $AUC_{0{\rightarrow}8hr}$ values in SD rats was $1994{\pm}335\;ng{\cdot}hr/mL$, which significantly increased (P<0.05) compared with raw atorvastatin calcium. The SMEDDS formulation was relatively stable when stored at $4^{\circ}C$ during 3 months. Our studies illustrated the potential use of SMEDDS for the delivery of hydrophobic compounds, such as atorvastatin, by the oral route.

• 한국멀티미디어학회논문지
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• 제13권2호
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• pp.287-297
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• 2010

홈 네트워크 환경에서의 디바이스의 안전한 사용을 위해서는 인증이 필요하다. 이러한 인증은 크게 ID기반의 인증 방식과 인증서 기반의 인증방식이 있다, ID기반의 방식의 경우에는 멀티도메인 환경에 적용이 어렵고, 인증서 기반 방식의 경우에는 인증서를 탑재 및 저장하는 방식이 디바이스에 종속되어 있어, 소유권의 이전, 새로운 장비의 구매 등에 대한 사용자의 추가 설정이 요구된다. 그리고 두 가지 방식 모두 디바이스에 대한 개별적인 인증이 이루어져, 사용자가 요구하는 서비스 측면에서는 다수의 디바이스에 대한 잦은 인증으로 오버헤드가 존재한다. 이러한 문제를 해결하기 위하여 본 논문에서는 자바 카드에 디바이스 인증정보를 안전하게 저장 및 관리하는 기법을 제안하며 또한 서비스단위의 그룹기반의 디바이스 인증 기법을 사용하여 기존의 기법들에 비해 보다 향상된 수행속도를 보장한다.

• 대한공간정보학회지
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• 제13권3호
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• pp.79-85
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• 2005

초기에 국가기본지형도는 DXF로 표현되어 저장, 공급되어 왔으며 현재의 수치지도는 대부분 이와 같은 형식으로 정비되어 있으나, 이를 지리정보시스템에서 수치지도를 직접 사용하기 위해서는 많은 부분을 새로이 가공하여야 하며, 특히 수치지도에 포함된 기하학적 모순과 논리적 모순에 의해 많은 구조화 편집과 지리조사 등이 요구되었다. 이와 같이 DXF는 지리정보시스템에서 사용되기에는 적합하지 않은 데이터 포맷이어서 보다 효율적인 포맷으로 전환이 필요하여, 그 결과 수치지도 Ver. 2.0이라는 새로운 지도포맷이 개발되었다. 본 연구에서는 새로운 형식의 수치지도 Ver. 2.0 형식으로 제작된 수치지도를 모바일 장비에서 바로 도시할 수 있는 수치지도 Ver. 2.0 Mobile Viewer 프로그램 개발을 수행하였다.

• 정보통신설비학회논문지
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• 제11권2호
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• pp.29-33
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• 2012

ECG widely used in cardiac function test is a graph that is recorded by measuring the electrical impulses occurred in the heart. Normal ECG has the form of similar sections that are repeated, and each section has the information occurred in a heart beat. Thus, In order to make the correct diagnosis, correct grasp of the sections and formed analysis must be done. In this research, a system that detects the sections of ECG is proposed. The system is based on ECG stored in the form of files. The ECG can easily have a noise caused by an outside factor. The noise of ECG is easily caused by external factors. Through a band-pass filter, it can be removed. and then, to get this ECG without a noise, interval detection algorithm using R-peak is applied. The clean, intuitive interface will help the above functions to be used without any difficulties.

• ETRI Journal
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• 제32권6호
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• pp.950-960
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• 2010

In response to increased security concerns, biometrics is becoming more focused on overcoming or complementing conventional knowledge and possession-based authentication. However, biometric authentication requires special care since the loss of biometric data is irrecoverable. In this paper, we present a biometric authentication framework, where several novel techniques are applied to provide security and privacy. First, a biometric template is saved in a transformed form. This makes it possible for a template to be canceled upon its loss while the original biometric information is not revealed. Second, when a user is registered with a server, a biometric template is stored in a special form, named a 'soft vault'. This technique prevents impersonation attacks even if data in a server is disclosed to an attacker. Finally, a one-time template technique is applied in order to prevent replay attacks against templates transmitted over networks. In addition, the whole scheme keeps decision equivalence with conventional face authentication, and thus it does not decrease biometric recognition performance. As a result, the proposed techniques construct a secure face authentication framework in open networks.

• 지식경영연구
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• 제19권2호
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• pp.47-68
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• 2018

Business environment is shifting from industrial economy to knowledge based economy. Enterprises go through numerous trials for successful management in changing environment. Along with trial tests, research area has been growing simultaneously. Unlike initial research which focused on basic concepts such as: form of business model and success points. Current research emphasizes on actualization of business that enterprises plan, which brought academic research with perplex form of knowledge structure. On the other hand, there is limitation in understanding business model systematically due to preceding research primarily centered on analyzing definition and case study. In order to analyze knowledge structure, this study utilized social network analysis based on "relationship". For the analysis, 13,412 keywords were extracted from 36years worth of article or research related to business model stored in SCOPUS database. From the analysis, it was shown core research subject was INNOVATION and the number of co-authors has increased due to the academic diversity. Business model research is divided into five sub-categories (E-commerce, SMEs, sustainability, open-source, and e-book). Through cognitive map analysis on each of research characteristics of sub-category, it has shown that E-commerce, SMEs, sustainability, and open-source are core categories.

• 한국대기환경학회지
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• 제15권2호
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• pp.151-158
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• 1999

Offsite consequences resulting form worst-case scenarios involving release of toxic substances in the Yochon area were estimated using the ALOHA(Areal Locations of Hazardous Atmospheres) model. Eight toxic substances, including NH3, were considered; five were toxic gases and three were toxic liquids at ambient temperature. For toxic gases, the entire quantity was assumed to be released at a constant rate during a 10-minute period. For toxic liquids, the entire quantity stored in the tank was assumed to be spilled and spread and spread instantaneously to form a pool with a depth of 1cm, and then evaporated over some period of time. Except for phosgene and toluene 2,4-diisocyanate, for which concentration levels corresponding to human health effects are very low, average distances of the area at risk of adverse health effects for a 1- tom release were predicted to be $2.3{\pm}1.1 km$ for the worst-case meteorological conditions and $0.93{\pm}0.69km$ under typical meteorological conditions of the Yochon are. Because a large number of people were predicted to be affected in the current analysis, refined analyses considering both realistic accident scenarios and topographic effects were warranted.

• 한국멀티미디어학회논문지
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• 제18권6호
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• pp.742-752
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• 2015

The communications through the power lines are called as the PLC and this is a common name for the communication modes for the information delivery. This technology transmits the data through the power lines on which the information is stored with the form of high frequency signal. The characteristic of the frequency signal is that the signal can be separated from the power line through exclusive power line modem and transmitted to the terminal devices. In this paper, 'In-home Headcount' checking algorithm using Wi-Fi and taking above mentioned advantages is proposed, and the basic Technology for such Solitary Senior Citizen's Lonely Death monitoring system has been designed and implemented. The comparative analysis has been conducted in this paper with the test-operated and test bed-completed 'Hyosimi 119 Safety-Welfare System' which is still being tested since 2008. With the 'In-home Headcount Checking Algorithm', Wi-Fi connection/disconnection status and SSIDs of relevant Wi-Fis will be checked. We expect that our proposed method will become as the basic Technology which can prevent lonely deaths of elderly people living alone. Since the PLC technology can be normally implement all the functions used on internet anticipate that the technology could be applied to many areas to construct a new form of communication network.

• 한국수소및신에너지학회논문집
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• 제15권2호
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• pp.152-158
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• 2004

Hydrogen has been considered as an important and essential future energy source. But the storage of the hydrogen is a difficult problem and many studies were focused on this matter. However, the MTH-system (methylcyclohexane, toluene, hydrogen) was proposed for storage of hydrogen by Taube et al. and that is the reaction of hydrogen with toluene to give methylcyclohexane. One toluene molecule can store six hydrogen atoms to form methylcyclohexane. In this form the hydrogen can be easily stored in liquid organic hydrides and transported at ambient pressure in tanks. Hence, this study is focused on the catalytic dehydrogenation of methylcyclohexane. Since supported platinum and nickel were employed as catalysts in literature, in this study, porous Pt and Ni were prepared and tested for the dehydrogenation reaction. When the porous Pt catalyst was applied to the dehydrogenation it showed higher activity in the reaction and higher selectivity to toluene. Specially at higher pressure, it showed almost 100 % conversion and 100 % selectivity and hence porous platinum could be considered as best for the given reaction.