• 한국의류산업학회지
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• 제14권6호
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• pp.983-991
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• 2012

The purpose of this study was to provide basic reference data for the development of slim-fit dress shirts patterns for a variety of body somatotypes. For this study, a survey was conducted on the actual product conditions of slim-fit dress shirts of domestic brands(Actual wearing and purchasing conditions, fit, design preferences). The survey was conducted on 135 men in their 20s~30s. PASW Statistics 18 was used for data analysis. The result of this study are as follows : Analysis of the actual wearing conditions of dress shirts indicates that consumers own an average of 1~2 classic-fit shirts and 1~4 slim-fit shirts. These are normally worn once or twice a week, and purchased mainly at department stores, agencies, direct sales markets or outlets. With respect to the purchasing factors, price and style were the main priorities. Surveyed consumers had the greatest preference for designs with a non-darted front and a darted back, a semi-wide collar and the color white. By classifying the surveyed by somatotype, Type B preferred designs darted on both front and back, Type A preferred designs with a non-darted front and a darted back, while Type Y preferred designs non-darted on both front and back. All somatotypes displayed a preference for semi-wide collars and the color white.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 춘계학술대회 논문집
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• pp.17-17
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• 2009

We report the invention of a direct growth method termed On-Film Formation of Nanowire (OFF-ON) for making high-quality single-crystal nanowires, i.e. Bi and $Bi_2Te_3$, without the use of conventional templates, catalysts, or starting materials. We have used the OFF-ON technique to grow single crystal semi-metallic Bi and compound semiconductor $Bi_2Te_3$ nanowires from sputtered Bi and BiTe films after thermal annealing, respectively. The mechanism for nanowire growth is stress-induced mass flow along grain boundaries in the polycrystalline films. OFF-ON is a simple but powerful method for growing perfect single-crystal semi-metallic and compound semiconductor nanowires of high aspect ratio with high crystallinity that distinguishes it from other competitive growth approaches that have been developed to date. Our results suggest that Bi and $Bi_2Te_3$ nanowires grown by OFF-ON can be an ideal material system for exploring their unique thermoelectric properties due to their high-quality single crystalline and high conductivity, which have consequence and relevance for high-efficiency thermoelectric devices.

• 반도체디스플레이기술학회지
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• 제14권4호
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• pp.25-29
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• 2015

In this study, RF magnetron sputtering was used to investigate the relationship between oxygen vacancy and carrier concentration in a GZO film on an amorphous structure. RF power was fixed at 50W and Ar flow was changed on a glass plate to create a thin film at room temperature. The transmittance of Al-adopted amorphous GZO was measured at 85% or higher; therefore, the transmittance was shown to be outstanding in all films. The hall mobility was also shown to be higher at the film showing the high transmittance at a short-wavelength, whereas the optical energy gap was shown to be higher at the film with high oxygen vacancy. The oxygen vacancy at the amorphous oxide semi-conductor increased the optical energy gap while it was not directly involved in increasing the mobility. The oxygen vacancy increases the carrier concentration while lowering the quality of amorphous structure; such factor, therefore affected the mobility. The increase of amorphous property is a direct way to increase the mobility of amorphous oxide semi-conductor.

• 한국환경과학회지
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• 제28권11호
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• pp.927-933
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• 2019

A lipid-enriched strain of Botryococcus braunii (UTEX 572) was cultivated in a semi-batch aeration tank to enhance biomass as well as to develop intracellular lipids and fatty acids. A 30 day period of incubation produced 1.39 g/L of biomass and 0.31 g/L of total lipids in the biomass. The grown biomass was pre-treated using several methods to extract the total lipid content efficiently: ultrasonication was found to yield the highest percentage of lipids-namely 19.8% per biomass. Direct heating of biomass in an autoclave also showed better performance than when using only conventional solvent extraction. To enhance the biomass harvest and lipid extraction efficiency, coagulation and flocculation steps were added to the extraction process. It is noteworthy that not only the solvent type but also the solvent/biomass ratio greatly affected efficiency. In addition, the moisture content of the harvested(wet) biomass affected the efficiency significantly. This study elucidated the need for future research on optimizing this extraction process.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2019년도 춘계학술대회
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• pp.288-289
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• 2019

This paper studies the secrecy capacity for a wireless cooperative network with perfect channel state information at the relays, and receiver. A similar assumption is also made for the instance where there exist a direct link between the transmitter and receiver. Physical Layer security techniques are employed in wireless networks to mitigate against the activity of eavesdroppers. It offers a viable alternative to computationally intensive encryption. In this paper the design of a protocol utilizing jamming (via jamming nodes) for better security and relaying (via relay nodes) for the amplify-and-forward (AF) operation, is investigated. A a signal-to-noise variant of secrecy known as secrecy gap is explored because of its use of lesser computational power - preferable for practical systems. Thus we maximize this signal-to-noise approach instead of the conventional secrecy capacity maximization method. With this, an iterative algorithm using geometric programming (GP) and semi-definite programming (SDP) is presented with appreciable benefits. The results show here highlight the benefits of using fractional components of the powers of the relays to offer better secrecy capacity.

• 대한산업공학회지
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• 제37권1호
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• pp.64-73
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• 2011

Oil price prediction is an important issue for the regulators of the government and the related industries. When employing the time series techniques for prediction, however, it becomes difficult and challenging since the behavior of the series of oil prices is dominated by quantitatively unexplained irregular external factors, e.g., supply- or demand-side shocks, political conflicts specific to events in the Middle East, and direct or indirect influences from other global economical indices, etc. Identifying and quantifying the relationship between oil price and those external factors may provide more relevant prediction than attempting to unclose the underlying structure of the series itself. Technically, this implies the prediction is to be based on the vectoral data on the degrees of the relationship rather than the series data. This paper proposes a novel method for time series prediction of using Semi-Supervised Learning that was originally designed only for the vector types of data. First, several time series of oil prices and other economical indices are transformed into the multiple dimensional vectors by the various types of technical indicators and the diverse combination of the indicator-specific hyper-parameters. Then, to avoid the curse of dimensionality and redundancy among the dimensions, the wellknown feature extraction techniques, PCA and NLPCA, are employed. With the extracted features, a timepointspecific similarity matrix of oil prices and other economical indices is built and finally, Semi-Supervised Learning generates one-timepoint-ahead prediction. The series of crude oil prices of West Texas Intermediate (WTI) was used to verify the proposed method, and the experiments showed promising results : 0.86 of the average AUC.

• 한국수산과학회지
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• 제30권2호
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• pp.264-270
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• 1997

연어육으로써 조미반건조 제품을 가공하기 위한 기초 자료를 조사하기 위하여 가공조건에 따른 texture의 변화를 측정한 결과는 다음과 같다. 건조시간과 열풍온도가 증가할수록 연어육의 수분함량은 감소하였고, 수분감소량에 비례하여 hardness, shear stress 및 adhesiveness는 증가하였다. 연어육 건조 중에 hardness, shear stress 및 cohesiveness의 상관관계는 hardness와 shear stress는 비례하였고 hardness와 cohesiveness는 반비례관계를 나타내었다. 당장 및 염장 후, 건조시간이 증가할수록 hardness와 shear stress는 증가하였다. 관능검사 결과, 3시간 이상 건조한 당장시료의 texture가 "약간 좋다" 이상을 보였다. 가열 중의 texture 변화에 있어서는 10시간 건조한 시료가 4시간 건조시료 보다 hardness 및 shear stress 값이 높았으며, 가열시간이 증가함에 따라 10시간 건조한 시료의 hardness는 큰 변화가 없었으나 4시간 건조한 시료에서 감소하였다. Cohesiveness의 경우 가열시간이 경과함에 따라 4시간 건조시료와 대조구는 감소하였으나 10시간 건조한 시료에는 거의 변화가 없었고 adhesiveness에 있어서는 가열시간에 따른 일정한 경향을 나타내지는 않았다.

• 한국대기환경학회지
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• 제28권1호
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• pp.39-51
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• 2012

Aerosol slurry samples were collected in 60-min interval using Korean Semi-continuous Elements in Aerosol Sampler (KSEAS) between May 19 and June 6, 2010 at an urban site of Gwangju. The $PM_{2.5}$ samples were collected with a flow rate of 16.7 L/min and particles are grown by condensation of water vapor in a condenser maintained at ${\sim}5^{\circ}C$ after saturation by direct injection of steam. The resulting droplets are collected in a liquid slurry with a airdroplet separator. Concentrations of 16 elements (Al, Fe, Mn, Ca, K, Cu, Zn, Pb, Cd, Cr, Ti, V, Ni, Co, As, Se) in the collected slurry samples were determined off-line by ICP-MS. KSEAS sample analysis encompassed the sampling periods for which 24-hr average elemental species concentrations were calculated for comparison with those derived from 24-hr integrated filter samples. Relationship between elemental species measured by two methods indicated high correlation coefficients (r), mostly greater than r of 0.80. However, we note that concentrations of Al, K, Ca, Mn, and Fe, which are often associated with crustal elemental particles, in the KSEAS samples, were substantially lower (1.4~11 times) than those found in the typical filter-based samples. This discrepancy is probably due to difficulties in transferring insoluble dust particles to the collection vials in the KSEAS. Temporal profiles of elemental concentrations indicate that some transient events in their concentrations are observed over the sampling periods. For the elemental species studied, atmospheric concentrations during the transient events increased by factors of 4 in Mn~80 in Zn, compared to their background levels. Principle component analyses were applied to the hourly KSEAS data sets to identify sources affecting the concentrations of the metal constituents observed. In this study, we conclude that hourly measurements for particle-bound elemental constituents were extremely useful for revealing the short-term variability in their concentrations and developing insights into their sources.

• 한국토양비료학회지
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• 제42권1호
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• pp.37-45
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• 2009

비점오염제어에 있어서 상대적으로 지하수오염의 가능성이 높은 지역을 선별하고 주된 오염원을 파악하는 것은 그 기여도가 대단히 크다. 이 연구는 제주도를 연구지역으로 하였으며, 현재 가장 중요한 오염물질 중의 하나인 질산태 질소를 대상오염물질로 하였다. 기존 및 실제 조사에 의한 토양정보를 토대로 pedotransfer function과 수분이동 모델을 이용하여 토양통별로 산출된 질산태질소오염 민감도 지수를 통해 민감도분포도를 작성하였으며(semi process-based 법), 이를 실제 모니터링된 2,020개의 수질자료와 비교하였고 제안된 semi process-based 법은 기존의 전문가의 의견과 판단에 의존하거나 방대한 파라메터를 요구하는 기존방법들의 단점을 극복하고 충분한 지형적 해상력을 제공하였을 뿐만 아니라, 알려진 질산태 질소 모니터링 자료와도 대부분 잘 부합하였다. 본 연구를 통해 얻어진 결과들은 오염민감성이 높은 지역을 우선 선정하여 주의와 관리대책을 세우는 동시에 주요한 오염원을 파악함으로써 지하수자원을 합리적이고 효율적으로 보호하는데 있어서 유용한 수단이 될 것으로 판단되었다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.510-511
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• 2017

본 논문에서는 현재 단수명 및 잔고장의 빈도가 높은 LED 조명기의 수명 및 고장 발생을 최소화 하고자 연구를 진행하였으며, 현재 LED 칩의 경우 수명이 반영구적이라고 할 수 있지만, LED 칩의 수명에 비해 LED 조명기의 구동드라이버는 수명이 길지 않다. 최근에는 중국산등의 저가 LED 조명기가 시장에 진입함으로써 많은 소비자로부터 LED 조명기의 인식이 나빠지고 있다. 이러한 문제점을 해결하고자 본 논문에서는 고장의 원인이 되는 LED 구동드라이버 부분에 있는 전해 콘덴서 부분을 제거하여 기존의 구동드라이버 보다 수명이 긴 AC Direct IC를 이용하여 25W급의 LED 조명기를 설계하였다.