• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.68.1-68.1
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• 2012

The best part of graphene is - charge-carriers in it are mass less particles which move in near relativistic speeds. Comparing to other materials, electrons in graphene travel much faster - at speeds of $10^8cm/s$. A graphene sheet is pure enough to ensure that electrons can travel a fair distance before colliding. Electronic devices few nanometers long that would be able to transmit charge at breath taking speeds for a fraction of power compared to present day CMOS transistors. Many researches try to check a possibility to make it a perfect replacement for silicon based devices. Graphene has shown high potential to be used as interconnects in the field of high frequency electrical devices. With all those advantages of graphene, we demonstrate characteristics of electrical and optical properties of graphene such as the effect of graphene geometry on the microwave properties using the measurements of S-parameter in range of 500 MHz - 40 GHz at room temperature condition. We confirm that impedance and resistance decrease with increasing the number of graphene layer and w/L ratio. This result shows proper geometry of graphene to be used as high frequency interconnects. This study also presents the optical properties of graphene oxide (GO), which were deposited in different substrate, or influenced by oxygen plasma, were confirmed using different characterization techniques. 4-6 layers of the polycrystalline GO layers, which were confirmed by High resolution transmission electron microscopy (HRTEM) and electron diffraction analysis, were shown short range order of crystallization by the substrate as well as interlayer effect with an increase in interplanar spacing, which can be attributed to the presence of oxygen functional groups on its layers. X-ray photoelectron Spectroscopy (XPS) and Raman spectroscopy confirms the presence of the $sp^2$ and $sp^3$ hybridization due to the disordered crystal structures of the carbon atoms results from oxidation, and Fourier Transform Infrared spectroscopy (FTIR) and XPS analysis shows the changes in oxygen functional groups with nature of substrate. Moreover, the photoluminescent (PL) peak emission wavelength varies with substrate and the broad energy level distribution produces excitation dependent PL emission in a broad wavelength ranging from 400 to 650 nm. The structural and optical properties of oxygen plasma treated GO films for possible optoelectronic applications were also investigated using various characterization techniques. HRTEM and electron diffraction analysis confirmed that the oxygen plasma treatment results short range order crystallization in GO films with an increase in interplanar spacing, which can be attributed to the presence of oxygen functional groups. In addition, Electron energy loss spectroscopy (EELS) and Raman spectroscopy confirms the presence of the $sp^2$ and $sp^3$ hybridization due to the disordered crystal structures of the carbon atoms results from oxidation and XPS analysis shows that epoxy pairs convert to more stable C=O and O-C=O groups with oxygen plasma treatment. The broad energy level distribution resulting from the broad size distribution of the $sp^2$ clusters produces excitation dependent PL emission in a broad wavelength range from 400 to 650 nm. Our results suggest that substrate influenced, or oxygen treatment GO has higher potential for future optoelectronic devices by its various optical properties and visible PL emission.

• Journal of Ginseng Research
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• 제41권3호
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• pp.339-346
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• 2017

Background: In this study, we investigated how to convert the Panax ginseng DNA sequence code and chemical fingerprints into a two-dimensional code. In order to improve the compression efficiency, GATC2Bytes and digital merger compression algorithms are proposed. Methods: HPLC chemical fingerprint data of 10 groups of P. ginseng from Northeast China and the internal transcribed spacer 2 (ITS2) sequence code as the DNA sequence code were ready for conversion. In order to convert such data into a two-dimensional code, the following six steps were performed: First, the chemical fingerprint characteristic data sets were obtained through the inflection filtering algorithm. Second, precompression processing of such data sets is undertaken. Third, precompression processing was undertaken with the P. ginseng DNA (ITS2) sequence codes. Fourth, the precompressed chemical fingerprint data and the DNA (ITS2) sequence code were combined in accordance with the set data format. Such combined data can be compressed by Zlib, an open source data compression algorithm. Finally, the compressed data generated a two-dimensional code called a quick response code (QR code). Results: Through the abovementioned converting process, it can be found that the number of bytes needed for storing P. ginseng chemical fingerprints and its DNA (ITS2) sequence code can be greatly reduced. After GTCA2Bytes algorithm processing, the ITS2 compression rate reaches 75% and the chemical fingerprint compression rate exceeds 99.65% via filtration and digital merger compression algorithm processing. Therefore, the overall compression ratio even exceeds 99.36%. The capacity of the formed QR code is around 0.5k, which can easily and successfully be read and identified by any smartphone. Conclusion: P. ginseng chemical fingerprints and its DNA (ITS2) sequence code can form a QR code after data processing, and therefore the QR code can be a perfect carrier of the authenticity and quality of P. ginseng information. This study provides a theoretical basis for the development of a quality traceability system of traditional Chinese medicine based on a two-dimensional code.

• 대한가정학회지
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• 제12권34호
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• pp.679-697
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• 1974

I. Preface A. Establishment. There are many psycological and physiological difficulties that students have made practical application to a building site of 600 pyung and a structure of 65 pyung each sixteen students in the Home Management House, but there exists problem in students apprentice and management of professors. B. Purpose of study This research aim to seek a high degree of efficiency approach in investigating, studying and analyzing factors of the problem in Home Management which have been faced in women colleges in seoul. C. Content of study. This study is aim at finding out the problems including facilites, system, guiding principle, working bottleneck and administrative problem in making practical application of Home Management. II. A plan and method of study A. This subject of statiscal research is 616 women students in senior year from september 27 1970 to October 31 1974. The rate of collection of questionnaire is 100 percent. B. The Method of study is devised through refering documents, interview with students, questionnaire and observation. III. Result of study Of the total of 29 university in seoul, 24 Universities have its Course of Home Economic among which only 12 have Home Management for making practical application. Home Management House for making practical application is located mainly in campus but some of them exceptimally are in outside university. Students practice mainly at civilzed resident, apartment, bangalow so forth, and demention of which occupies approxiamtely 50-600 pyung (land) and 20-70 pyung (Building). A member with 4 or 20 students make practical application from 10 days to 3 months. A member consists of students and assistant teacher, and practice site classifies into living school for Professors living, and another school for Professors and assistant teachers. Answer to a questionnaire. 616 students answer to a questionnaire. 49 Perfect of 616 students like to have a member with 12 students like to have a member with 12 students, 38 percent student a member with 16 students. About the period of making practical About the period of making practical application, 76 percent students like to have two or three week period. 19 percent students think it a short period and 4 percent students think it a long period. There is none who thinks 25 day period day period to be short. About making practical application, 66 percent of 616 students feel uneasy, 40 percent students feel lack of sleep and tired. Students take a pleasure in having a conversation with their friends, inviting their mother, having dinner-party and birthday party. 77 percent students want to invite their father and 67 percent students want to invite their boy-friends. It is hard to have a good personal relation about the great the result of practice, students acknowledge themselves that they have learned about Cautiousness and they are sure of good Home Manager. There are 9 difficult problems during the period. IV. Summary discussion a. Many problems come from having a number of students. b. Students feel tired with their practice if over three weeks. No Matter how good a plan is, it useless if students can't adapt themselves to it. Suggestions 1) it is good to have a member with 5 or 6 students, and it is suitable to have two or three week period, and to have an area of 20 or 30 pyung. 2) it's proposed a profess or to live together in making practical application of Home Management 3) it is proposed a professor to have a sure T.O. and to be treated better.

• 한국균학회지
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• 제10권1호
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• pp.7-13
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• 1982

자연상태(自然狀態)에서 Didymella bryoniae에 이병(罹病)된 오이 및 호박 종자(種子)를 습지법(濕紙法)으로 처리(處理)하여 불완전(不完全) 세대(世代)와 완전세대(完全世代)의 특징(特徵)을 조사(調査)하고 Difco PDA, V-8쥬스한천(寒天) 및 water agar leaf medium에서의 특징(特徵)과 비교(比較) 하였다. 병든 종자(種子)가 발아(發芽)할 때 종피(種皮)나 배축(胚軸)에 형성(形成)된 Didymella bryoniae의 병포자(柄胞子)와 Difco PDA, V-8 juice한천(寒天) 및 WALM에 형성(形成)된 본균(本菌)의 병포자(柄胞子)는 형태적(形態的)으로 많은 차이(差異)가 나타난다. 즉 PDA에 형성(形成)되는 병포자(柄胞子)는 무색(無色) 소형단포자(小型單胞子)가 대부분이며, V-8 juice한천(寒天) 및 WALM에 형성(形成)되는 것은 대형단포자외(大型單胞子外)에 격막(隔膜)이 하나 있는 포자(胞子)를 형성하고 또 균주(菌株)에 따라서는 격막(隔膜)이 두개 있는 포자(胞子)를 형성하므로써 마치 병든 종피(種皮)나 배축(胚軸)에 형성(形成)된 것과 흡사하였다. 한편 자양각은 병든 종자(種子)의 표본(標本)에 따라 잘 형성(形成)되는 것도 있었으나 대부분(大部分)의 표본(標本)에서는 형성(形成)되지 않았다. 외부형태적(外部形態的)인 특징(特徵)은 색깔이 진한 흑색(黑色)이며 유두상각공(乳頭狀殼孔) 위에 백색(白色)의 포자괴(胞子塊)가 형성(形成)되는 특징(特徵)을 가지고 있어서 쉽게 병자각(柄子殼)과 구별(區別)할 수 있었다. 불완전(不完全) 세대(世代)인 병자각(柄子殼)이나 병포자(柄胞子)와 같이 자양각의 각방(殼房)과 포자(胞子)의 크기에는 큰 변이(變異)가 없었다.

• 문화기술의 융합
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• 제8권4호
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• pp.303-311
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• 2022

최근 COVID-19 이후 한시적 허용을 통해 증가하고 있는 비대면진료 플랫폼 기업에서 온라인 처방약 배송까지 함께 제공하는 경우가 증가하고 있어 이에 대한 기존 의약품공급자들의 우려가 커지는 가운데 적극적인 대응 움직임도 나타나고 있다. 본 연구에서는 게임이론의 시장 진입 저지 모형을 중심으로 기존 의약품공급자의 선제적 적극 대응이 성공적으로 시행될 수 있을 경우 온라인 의약품배송기업의 시장 진입을 억제할 수 있으나, COVID-19 이후 비대면진료의 한시적 허용에 따라 비대면진료 및 처방약 배송 플랫폼의 시장 진입이 효과적으로 이루어진 상황에서는 기존 의약품공급자의 수용적 대응이 보다 합리적인 선택이 될 수 있음을 보였다. 다만, 소비자 편이성 증대 방향의 소매 의약품유통시장 관련 제도 개선에 기존 의약품공급자들이 보다 전향적으로 협력할 수 있도록 온라인 처방약 배송 플랫폼 기업에 참여하는 약사들에 대해 일일 처방전 접수 건수에 상한선을 설정하는 방법, 의약품배송 약국 선택 시 기존 이용 약국 및 의료이용자의 거주지역 지역사회 약국이 우선 소개될 수 있도록 플랫폼 사용자 환경에 노출 방식 및 노출 시간 등을 조정하는 방안, 장기적으로 비대면진료 및 의약품배송 플랫폼 기업의 기업 공개 시 지역사회 약국 등이 자본 참여할 수 있는 방안 등이 고려될 필요가 있다.

• 한국음향학회지
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• 제41권5호
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• pp.492-499
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• 2022

본 연구에서는 진동 신호의 차원 감소가 선박 엔진의 고장진단에 미치는 영향을 실험적으로 분석한 결과를 제시한다. 주성분 분석을 이용하여 513차원의 진동 신호를 1 ~ 15차원의 저차원 신호로 변환하여 차원 변화에 따른 고장진단 정확도의 변화를 관찰하였다. 실제 규모의 선박용 발전기 디젤 엔진에서 측정된 진동 신호를 사용하고, integrated gradients와 feature permutation 기법의 두 가지 변수 중요도 분석 알고리즘을 사용하여 차원 축소 신호의 기여도를 정량적으로 평가하였다. 실험 데이터 분석 결과, 사용하는 차원의 수가 증가할수록 결함 진단의 정확도가 향상되는 것으로 나타났다. 차원이 10 이상에 다다르면 거의 모든 고장상태가 정확하게 분류되었으며, 이는 고장진단 정확도를 저하시키지 않으면서도 진동 신호의 차원수를 크게 줄일 수 있음을 보여준다. 변수 중요도 분석에서도 차원 축소 주성분이 기존 통계적 특성보다 더 높은 기여도를 보였으며, 차원 축소된 진동 스펙트럼이 고장진단에 효과적으로 사용될 수 있음을 확인하였다.

• 인터넷정보학회논문지
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• 제23권2호
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• pp.53-59
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• 2022

3단계 자율주행 차량 이후, 4, 5단계의 자율주행 기술은 차량의 완벽한 주행뿐만 아니라 탑승객의 상태를 최적으로 유지하기 위해 노력하고 있다. 그러나 현재 자율주행 기술은 LiDAR, 전방 카메라 등 시각적 정보에 과하게 의존하기 때문에 지정된 도로 이외의 도로에서 완벽하게 자율주행을 실행하기 힘들다. 따라서 본 논문은 차량이 시각 정보 외의 데이터를 사용하여 도로의 상태를 분류하고, 도로 상태와 주행 상태에 따라 최적의 제동 강도를 계산하는 BSCS (Braking Strength Calculation System)를 제안한다. 본 논문에서 제안하는 BSCS는 KNN 알고리즘을 기반으로 도로의 상태를 분류하는 RCDM (Road Condition Definition Module)과 RCDM의 결과와 현재 주행 상태를 통해 주행 중 최적의 제동 강도를 계산하는 BSCM (Braking Strength Calculation Module)로 구성된다. 본 논문의 실험 결과, KNN 알고리즘에 가장 적합한 K의 수를 찾을 수 있었고, 비지도 학습인 K-means 알고리즘보다 본 논문에서 제안한 RCDM이 더 정확한 것이 증명되었다. 해당 논문의 BSCS는 시각 정보뿐만 아니라 서스펜션에 가해지는 진동 데이터를 사용함으로써, 시각 정보가 제한되는 여러 환경에서 자율주행 차량의 제동을 더 원활하게 만들 수 있다.

• 한국항공우주학회지
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• 제50권12호
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• pp.889-898
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• 2022

본 논문에서는 3차원 전자기장의 병렬 해석 기법을 제안하였다. 시간 조화 벡터 파동 방정식 및 유한요소 기법에 기반한 전자기장 산란 해석이 수행되었으며, 모서리 기반 요소 및 2차 흡수 경계 조건이 도입되었다. 개발한 알고리즘은 유한요소망을 분할한 뒤 각 프로세서에 할당함으로써 요소별 수치적분 및 행렬 조립 과정의 병렬화를 달성하였다. 이때 부영역 생성을 위해 그래프 분할 라이브러리인 METIS가 도입되었다. 대형 희박행렬 방정식의 계산은 다중 프론탈 기법 기반 병렬 연산 라이브러리인 MUMPS를 통해 수행되었다. 개발된 프로그램의 정확도는 Mie 이론해 및 ANSYS HFSS 결과와의 비교를 통해 검증되었다. 또한 사용된 프로세서 수에 따른 가속 지표를 측정하여 확장성을 확인하였다. 완전 전기 도체 구, 등·이방성 유전체 구 및 유도탄 예제 형상에 대한 전자기장 산란 해석이 수행되었다. 개발된 프로그램의 알고리즘은 추후 유한요소 분할 및 합성법에 활용될 예정이며, 더욱 확장된 병렬 연산 성능을 목표하고자 한다.

• Asia Marketing Journal
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• 제16권1호
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• pp.35-69
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• 2014

The impact of competition on pricing has been studied in the context of counterfactual merger analyses where expected optimal prices in a hypothetical monopoly are compared with observed prices in an oligopolistic market. Such analyses would typically assume static decision making by consumers and firms and thus have been applied mostly to data obtained from consumer packed goods such as cereal and soft drinks. However such static modeling approach is not suitable when decision makers are forward looking. When it comes to the markets for durable products with indirect network effects, consumer purchase decisions and firm pricing decisions are inherently dynamic as they take into account future states when making purchase and pricing decisions. Researchers need to take into account the dynamic aspects of decision making both in the consumer side and in the supplier side for such markets. Firms in a two-sided market typically subsidize one side of the market to exploit the indirect network effect. Such pricing behaviors would be more prevalent in competitive markets where firms would try to win over the battle for standard. While such qualitative expectation on the relationship between pricing behaviors and competitive structures could be easily formed, little empirical studies have measured the extent to which the distinct pricing structure in two-sided markets depends on the competitive structure of the market. This paper develops an empirical model to measure the impact of competition on optimal pricing of durable products under indirect network effects. In order to measure the impact of exogenously determined competition among firms on pricing, we compare the equilibrium prices in the observed oligopoly market to those in a hypothetical monopoly market. In computing the equilibrium prices, we account for the forward looking behaviors of consumers and supplier. We first estimate a demand function that accounts for consumers' forward-looking behaviors and indirect network effects. And then, for the supply side, the pricing equation is obtained as an outcome of the Markov Perfect Nash Equilibrium in pricing. In doing so, we utilize numerical dynamic programming techniques. We apply our model to a data set obtained from the U.S. video game console market. The video game console market is considered a prototypical case of two-sided markets in which the platform typically subsidizes one side of market to expand the installed base anticipating larger revenues in the other side of market resulting from the expanded installed base. The data consist of monthly observations of price, hardware unit sales and the number of compatible software titles for Sony PlayStation and Nintendo 64 from September 1996 to August 2002. Sony PlayStation was released to the market a year before Nintendo 64 was launched. We compute the expected equilibrium price path for Nintendo 64 and Playstation for both oligopoly and for monopoly. Our analysis reveals that the price level differs significantly between two competition structures. The merged monopoly is expected to set prices higher by 14.8% for Sony PlayStation and 21.8% for Nintendo 64 on average than the independent firms in an oligopoly would do. And such removal of competition would result in a reduction in consumer value by 43.1%. Higher prices are expected for the hypothetical monopoly because the merged firm does not need to engage in the battle for industry standard. This result is attributed to the distinct property of a two-sided market that competing firms tend to set low prices particularly at the initial period to attract consumers at the introductory stage and to reinforce their own networks and eventually finally to dominate the market.

• 한국컴퓨터정보학회논문지
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• 제29권4호
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• pp.105-114
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• 2024

본 연구에서는 부적응적 완벽주의, 셀프리더십, 사회적 지지가 간호대학생의 임상실습 스트레스에 미치는 영향을 파악하고자 한다. C지역에 소재한 4개의 간호대학에 재학 중인 3, 4학년 간호대학생 150명을 대상으로, 2022년 11월 3일부터 30일까지 완벽주의 척도(APS-R), 셀프리더십 척도(SLQ-R), 사회적 지지 척도(SSS), 임상실습 스트레스 척도(CPSS-R)를 사용하여 자료수집을 하였다. 연구결과, 대상자의 임상실습 스트레스는 부적응적 완벽주의(r=.51, p<.001)와 정적인 상관관계가, 셀프리더십(r=-.11, p<.001)과 사회적 지지(r=-.44, p<.001)와 부적인 상관관계가 있었다. 간호대학생의 임상실습 스트레스에 미치는 영향 요인은 부적응적 완벽주의(β=.45, p<.001), 사회적 지지(β= -.27, p<.001), 전공만족도(β=-.21, p=.002), 타 지역 임상실습 횟수(β=-.19, p=.003) 순으로 높게 나타났고, 이들 요인의 설명력은 43%였다(F=28.63, p<.001). 이상의 연구결과는 부적응적 완벽주의가 높을수록, 사회적 지지가 낮을수록 임상실습 스트레스가 높아질 수 있음을 시사한다. 따라서 향후 간호대학생을 대상으로 임상실습 스트레스를 낮출 수 있는 프로그램 개발 시 이러한 심리적 특성 요인들에 대한 적극적 고려가 중요하다고 본다.