• 디지털융복합연구
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• 제12권8호
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• pp.351-359
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• 2014

보안 장비에서 발생하는 로그는 그동안 ESM(Enterprise Security Management) 기반으로 통합적으로 데이터를 분석하였으나 데이터 저장 용량의 한계와 ESM자체의 데이터 처리 성능의 한계로 빅데이터 처리에 부적합하기 때문에 빅데이터 플랫폼을 이용한 보안로그 분석 기술이 필요하다. 빅데이터 플랫폼은 Hadoop Echosystem을 이용하여 대용량의 데이터 수집, 저장, 처리, 검색, 분석, 시각화 기능을 구현할 수 있다. 현재 ESM기술은 SIEM(Security Information & Event Management)방식으로 기술이 발전하고 있으며 SIEM방식의 보안기술을 구현하기 위해서는 현재 보안장비에서 발생하는 방대한 로그 데이터를 처리할 수 있는 빅데이터 플랫폼 기술이 필수적이다. 본 논문은 Hadoop Echosystem 이 가지고 있는 빅데이터 플랫폼 기술을 활용하여 보안로그를 분석하기 위한 시스템을 어떻게 구현할 수 있는지에 대한 모델을 연구하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.426.2-426.2
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• 2016

Numerous of researches are being conducted to improve the efficiency of $Cu_2ZnSnSe_4$ (CZTSe)-based photovoltaic devices, which is one of the most promising candidates for low cost and environment-friendly solar cells. In this work, we concentrate on the back contact of the devices. A proper thickness of $MoSe_2$ in back contact structure is believed to enhance adhesion and ohmic contact between Mo back contact and absorber layer. Nevertheless, too thick $MoSe_2$ layers that are grown during high-temperature selenization process can impede the current collection, thus resulting in low cell performance. By applying molybdenum nitride as a barrier in back contact structure, we were able to control the thickness of $MoSe_2$ layer, which resulted in lower series resistance and higher fill factor of CZTSe devices. The phase transformation of Mo-N binary system was systematically studied by changing $N_2$ concentration during the sputtering process. With a proper phase of Mo-N fabricated by using an adequate partial pressure of $N_2$, the efficiency of CZTSe solar cells as high as 8.31% was achieved while the average efficiency was improved by about 2% with respect to that of the referent cells where no barrier layer was employed.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1619-1619
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• 2001

Ourwork aims to assess the content of dry matter, protein, cell wall parameters and water soluble carbohydrates in forages without having to handle samples, transport them to a laboratory, dry, grind and chemically analyze them. for this purpose, the concept of fresh forage analysis under field conditions by means of compact integrated NIRS InGaAs-diode array instruments on small plot harvesters is being evaluated for plant breeding trials. This work was performed with the world first commercial experimental forage plot harvester equipped with a NIRS module for the collection, compression, and scanning of forage samples (including automatic referencing and dark current measure ments). It was used for harvesting and analyzing a number of typical forage grass and forage legume plot trials. After NIRS measurements in the field each sample was again analyzed in the laboratory by means of a conventional grating spectrometer equipped with Si-and PbS-detectors. Conventional laboratory analysis of the samples was restricted to dry matter (DM) content by means of oven drying at 105. Routine chemometric procedures were then employed to assess the comparative accuracy and precision of the DM assessments in the spectral range between 950 and 1650nm by the NIRS diode array as well as by the conventional NIRS scanning instrument. The results of this study confirmed that the type of NIRS diode array instrument employed here functioned well even in rugged field operations. further refinements proved to be necessary for optimizing the automatic filling of the sample compartment to adjust for the wide variation in forage material under conditions of extremely low or high harvest yields. The error achieved in calibrating the apparatus for forages of typical DM content proved to be satisfactory (SECV < 1.0). Possibly as a consequence of higher sampling errors, its performance in atypical forages with elevated DM contents was less satisfactory. The error level obtained on the conventional grating NIR spectrometer was similar to that of the diode array instrument for both types of forage.

• 조명전기설비학회논문지
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• 제21권3호
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• pp.35-43
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• 2007

본 논문에서는 전자 유도 법칙을 이용한 차량용 유도 전력 집전장치가 제안하였으며 전력 전송 특성을 개선하기 위한 전력 집전체의 몇 가지 설계에 관련된 개점을 제시하였다. 또한 다양한 공진 주파수로 동작되는 직렬 공진 컨버터와 연결하여 전력 전송 시스템의 해석을 나타내었다. 동작 주파수와 파라미터의 변동에 대한 시스템의 민감도가 고려되며, 유도 전력 전송 시스템에 있어서 전력은 코일이나 트랙의 형태인 1차 권선을 통하여 하나, 혹은 그 이상의 절연된 급전 코일로 전송된다. 본 논문은 유도전력전송의 집전장치의 구조를 기존변압기와 유사한 등가회로의 파라미터로 구성하고, 공극 및 권선을 고려한 1차, 2차측 파라미터를 설정하여 1차측 급전 주파수의 변화에 따른 집전특성에 대하여 기술하였다.

• Current Photovoltaic Research
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• 제5권1호
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• pp.20-24
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• 2017

Recently, three-dimensional (3D) light harvesting structures are highly attracted because of their high light harvesting capacity and charge collection efficiencies. In this study, we have fabricated $Cu_2ZnSn(S_xSe_{1-x})_4$ based 3D thin film solar cells on PR patterned Molybdenum (Mo) substrates using photolithography technique. Specifically, Mo patterns were deposited on PR patterned Mo substrates by sputtering and the thin Cu-Zn-Sn stacked layer was deposited over this Mo patterns by sputtering technique. The stacked Zn-Sn-Cu precursor thin films were sulfo-selenized to form CZTSSe pattern. Finally, CZTSSe absorbers were coated with thin CdS layer using chemical bath deposition and ZnO window layer was deposited over CZTSSe/CdS using DC sputtering technique. Fabricated 3-D solar cells were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF) analysis, Field-emission scanning electron microscopy (FE-SEM) to study their structural, compositional and morphological properties, respectively. The 3% efficiency is achieved for this kind of solar cell. Further efforts will be carried out to improve the performance of solar cell through various optimizations.

• 한국정보통신학회논문지
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• 제20권8호
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• pp.1569-1580
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• 2016

2.4 GHz 능동형 RFID가 보다 활성화되기 위해 개선되어야 할 요인 중 하나는 배터리 수명 문제다. 그러나 현재 까지 소비 전력 예측을 위한 정확한 모델이 존재하지 않는다. 본 연구에서는 태그의 전력 소비를 정확하게 예측 할 수 있는 시뮬레이션 모델을 개발하였다. 충돌 제어와 query 명령어 사용 방법에 따라 6개의 시뮬레이션 모델을 제안 하였다. 예측 정확도를 높이기 위하여 태그의 작동 모드를 몇 개로 분류하고 그에 따른 전력 소비와 작동 시간을 조사하였다. 태그 수집과 응답 확인 과정을 간소화 하는 Query command 명령 방법과 최근에 제안된 충돌 제어 알고리즘을 본 시뮬레이션 모델에 사용하였다. 소비 전력 이외에도 시스템 효율과 다중 태그의 인식 시간, 그리고 인식률과 같은 성능 지표를 구하여 기존의 ISO/IEC 18000-7 시스템과 비교하였다.

• 한국산업보건학회지
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• 제9권2호
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• pp.167-176
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• 1999

A new analytical procedure for the measurement of monomeric isocyanates and total isocyanate group in workplaces has been investigated. The method described herd involves derivatization of the isocyanate sample upon collection with the reagent 9-anthracenylmethyl 1-piperazinecarboxylate (PAC). Laboratory investigations have demonstrated that excess PAC reagent can be satisfactorily removed from PAC-derivatized monomeric isocyanates-a requirement for the success f the analytical procedure. After removal of excess PAC reagent, the PAC derivatives of butyl isocyanate, phenyl isocyanate, HDI, MDI, and TDI were reacted with sodium thiomethoxide to convert them all to 9-anthracenylmethyl methyl sulfide (AMMS). Total isocyanate group was determined by HPLC analysis and quantification of the single AMMS peak. This circumvents many of the disadvantages associated with current HPLC methods. There were no longer problems associated with quantifying late-eluting peaks and analysis times were very short. A single detector was used for quantification because a standard of the analyte existed and the retention time could be determined. Because all species were converted to a single analyte, the problem of variability of response factors among different species was averted. Finally, there were no complex chromatograms to interpret. Monomers of other individual species were measured by analysis of the sample before the individual species were converted to AMMS. The favorable performance of PAC warrants its further study as a reagent for the determination of total isocyanate group in air.

• 패션비즈니스
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• 제14권5호
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• pp.195-215
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• 2010

The emergence of the luxury market has led numerous academic researchers, as well as marketers in the luxury market, to pay attention to both identifying luxury brand features and measuring perceptions toward luxury brands. Especially, Korea is a significant emerging market for luxury goods. Young consumers and male consumers are getting into the luxury market fast and these new segments will keep increasing. There are only a few studies related to distinctive definitions of luxury brands and measurement development for the Korean market. However, there are some limitations in these previous studies in that they did not capture the nature of luxury due to their inappropriate of subjects and approach in data collection and to lack of a perspective of Korean specific features. Thus, the purpose of this research is to identify Korean consumers' perceptions toward luxury products and, ultimately, to develop a reliable and valid measurement items for the luxury products' features for the Korean market. Defining the three high constructs(functional, emotional, and symbolic aspects) as a key needs and benefits on luxury brands, we looked at four stages of development for generating and deducting items by luxury industry experts and luxury consumers, as well as for testing measures by 20th~60th consumers. As a result, this study confirmed that luxury brands consists of high quality, high price, unique design, and luxury store; the emotional aspect construct combines craftsmanship, VIP service, and high social status; and the symbolic construct includes brand heritage and being a well-known brand. Finally, 22 measurement items (Measures of Luxury Brand for Korea: LBK) were developed for the conceptual features for luxury brands from a Korean perspective. This study provided understanding of Korean consumers' perceptions toward luxury brands from an academic perspective. For the managerial implication of this study, LBK can be utilized to judge both luxury brands and mass brands, to diagnose current a brand's luxuriousness, from the customer's point-of-view, and, finally, to measure a Key Performance Index (KPI) of luxury brand companies.

• 한국입자에어로졸학회지
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• 제12권4호
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• pp.115-126
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• 2016

Numerical analysis was done to evaluate the movement of the particles and the fluid inside of the cyclone-bag hybrid dust collector. Flow discharged from the cyclone in the hybrid particle collector has swirl pattern, and it results in the biased flow to the bag filters and deteriorates the collection performance of the bag filter. The current study is to evaluate the effect of the duct lengths and the baffle arrays in the connection duct by the computational methods. Main concerns of the analysis are how to improve the uniformity of the internal flow between the cyclone and the bag filter. Numerical analysis was done to check the particle removal efficiencies of the system with respect to the flow characteristics which is expressed in RMS values of the upward flow inside of the connection duct. The flow pattern inside of the connection duct is evaluated under different the duct lengths and the baffle arrays. In case of the reference geometry the RMS value of inside flow was 56.7%, and the value was decreased to 30.1% by controlling the lengths of duct. The effects of baffle was also evaluated, the RMS value of flow could be decreased 55.2% and so on. But the pressure drop across the baffles becomes high and the system efficiency becomes lower.

• 한국철도학회논문집
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• 제15권5호
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• pp.447-453
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• 2012

본 논문은 경부 고속선과 같이 사전이도가 주어지는 기설 전차선로에서 전차선 장력만을 증가시켜 임시적인 속도 향상 도모하는 경우에 팬터그래프와 습동하는 전차선의 접촉 평면상의 기하학적 형상의 변화가 어떻게 될 것인가를 검토한 것이다. 검토를 위하여 우선 사전이도가 있는 경우에도 정확히 드로퍼 길이를 계산해 낼 수 있는 드로퍼 길이 계산 수식에 대하여 알아보았다. 다음으로 드로퍼 길이 계산 수식을 프로그램화한 전용계산 프로그램을 이용하여 경부고속선 전차선로의 49.5m 경간을 대상으로 전차선 장력을 20kN에서 23kN 및 25kN으로 증가시켰을 때 사전이도량의 변화를 계산하여보았다. 그리고 경부 2단계 구간 현장에서 실제 장력 증가 실험을 실시하여 사전이도량의 변화를 측정하였다. 측정 결과는 계산 값과 비교 검토를 수행하였으며, 결론적으로 전차선 장력을 증가시켜도 기하학적 형상의 변화는 미미하며 집전 성능에 별 영향이 없을 것임을 확인하였다.