• Title/Summary/Keyword: STEP-Manufacturing

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Heat Treatment of Cu0.9In0.7Ga0.3Se2 Powder Layer with a Mixture of Selenium and Ceramic Powder (셀레늄과 세라믹 혼합분말을 사용한 Cu0.9In0.7Ga0.3Se2 분말층의 소결거동 연구)

  • Song, Bong-Geun;Hwang, Yoonjung;Park, Bo-In;Lee, Seung Yong;Lee, Jae-Seung;Park, Jong-Ku;Lee, Doh-Kwon;Cho, So-Hye
    • Current Photovoltaic Research
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    • v.2 no.3
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    • pp.115-119
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    • 2014
  • $Cu(In,Ga)Se_2$ (CIGS) thin films have been used as a light absorbing layer in high-efficiency solar cells. In order to improve the quality of the CIGS thin film, often selenization step is applied. Especially when the thin film was formed by non-vacuum powder process, selenization can help to induce grain growth of powder and densification of the thin film. However, selenization is not trivial. It requires either the use of toxic gas, $H_2Se$, or expensive equipment which raises the overall manufacturing cost. Herein, we would like to deliver a new, simple method for selenization. In this method, instead of using a costly two-zone furnace, use of a regular tube furnace is required and selenium is supplied by a mixture of selenium and ceramic powder such as alumina. By adjusting the ratio of selenium vs. alumina powder, selenium vaporization can be carefully controlled. Under the optimized condition, steady supply of selenium vapor was possible which was evidently shown by large grain growth of CIGS within a thin powder layer.

Impact of Entrepreneurial Morality on Financial Performance and Social Performance through Entrepreneurship and Social Responsibility (기업가의 도덕성이 기업가정신 및 사회적 책임을 통한 재무적 성과와 사회적 성과에 미치는 영향)

  • Kim, Yeon Jong;Park, Sang Hyeok;Oh, Seung Hee
    • The Journal of Information Systems
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    • v.29 no.1
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    • pp.137-158
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    • 2020
  • Purpose This study aims to analyze how entrepreneurs' morality affects entrepreneurship and social responsibility. The purpose of this study is to analyze the differences of entrepreneurship and social responsibility on corporate financial performance and social performance by measuring entrepreneurial morality index. Design/methodology/approach The research model is based on the existing literature related to morality, entrepreneurship, social responsibility, and corporate performance. In order to verify the research model, empirical analysis was conducted. The collected data were analyzed by Smart-pls 2.0 based on the structural equation model based measurement model verification and the structural model verification two - step approach. Using the bootstrapping method of PLS, 500 samples were constructed and hypothesis verification was performed. Findings The results of this study are as follows. In the case of general manufacturing companies, business people are more focused on improving corporate performance than morality, and have a somewhat consistent effect with entrepreneurial spirit that does not have a space of morality. When entrepreneurship is strengthened, financial performance and social performance. Business entrepreneurs in social enterprises are more aware of social responsibility than entrepreneurship, so they achieve both financial performance and social performance at the same time. As a result of this study, it was found that there is a difference in perception depending on the morality of the business people, entrepreneurship, social bookkeeping, and management performance according to the type of company.

Development of an Ergonomic Checklist for the Investigation of Work-related Lower Limb Disorders in Farming - ALLA: Agricultural Lower-Limb Assessment (농작업에서 발생하는 하지자세의 근골격계 질환 위험도 평가를 위한 인간공학적 평가도구 개발)

  • Kong, Yong-Ku;Han, Jun-Goo;Kim, Dae-Min
    • Journal of the Ergonomics Society of Korea
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    • v.29 no.6
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    • pp.933-942
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    • 2010
  • Objective: To develop an ergonomic evaluation tool which can be apply to assess the lower-limb postures associated with farming tasks. Background: In general, most of existing ergonomic assessment tools was developed to investigate the work-related musculoskeletal disorders of the upper-limb postures in manufacturing industry. Methods: As the first step of development of the evaluation tool, 13 lower-limb postures that were commonly observed in farming task were investigated by the subjective discomfort ratings, heart rates, and muscle activities. And then, an ergonomic evaluation tool for the lower-limb postures was developed based on results of the first experiment. Lastly, the ergonomic checklist which was developed in the current study was compared with other existing ergonomic assessment tools. Results: Based on the results of comparisons between a newly developed assessment tool and other existing assessment tools, it was found that a newly developed tool can perceive more sensitively for the various lower-limb postures than other assessment tools. Conclusions: Lower-limb posture assessment tool which can evaluate and assess risks of lower-limb WMSDs which were prevalent in farming tasks more easily and accurately was developed in this study. The lower-limb assessment tool can also be utilized to prevent WMSDs related with lower-limbs as well as improve working environments.

A Study of Pace Strategy & Correlation of Product Liability Management Activity, Enterprise Value (제조물책임(製造物責任) 관리활동(管理活動)과 기업(企業) 가치(價値)간의 상관관계 및 대응전략(對應戰略) 연구)

  • Min, Dong-Seong;Chang, Seog-Ju;Park, Roh-Gook
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.3 no.3
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    • pp.17-65
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    • 2008
  • The manager of manufacturing industry just not to have known to do related to the law of Product Liability that was put into operation in July 2002. The law of PL is a public law about defective product, which was established in order to compensate consumer's damages of property and body caused by product, to make sound society by the safety products and to take international competitiveness. The economic effects by the law of Product Liability are the increase of consumers relief production cost by the lawsuits. Product liability as a process has developed significantly in the United Kingdom and the United States of America. The rapid introduction of product liability has recently been a prevalent phenomenon, as global changes arising from rapid development in science and the economy have resulted in a highly interconnected world economy. This thesis was established, based on current literature and business consulting cases in the position of companies, and is one of the operating subjects in a system for legal responsibility in manufactured products. However, there are limitations in the fact that research theories are only able to present a theoretical model and directions. In this context, managers and personnel of multiple companies cannot adequately respond to the recently enforced Product Liability Act. The major findings are summarized as Product Liability Management Activity are positively Correlation of Enterprise Value.

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A Study on the Safety Regulation Revision for Urban Transit Vehicles (도시철도차량의 안전기준 강화에 관한 연구)

  • Lee Woo-Dong;Shin Jeong-Ryol;Kim Gil-Dong;Han Suk-Youn;Park Kee-Jun;Hong Jai-Sung;Ahn Tai-Ki;Lee Ho-Yong;Kim Jong-Wook
    • Proceedings of the KSR Conference
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    • 2003.10c
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    • pp.322-326
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    • 2003
  • Dae-gu subway accident raise whole points in connection with safety facilities and operating of national urban transit system like rolling stocks, facilities, management of human. Rolling stock is made every effort for improvement of performance, guarantee of comfortableness, insurance of economical efficiency. But Security like safety of fire is not thoroughgoing enough. Especially, interior material has used although it is not prove its degree of safety. it is a main cause of Dae-gu subway accident. Safety regulation of urban transit vehicle that legislate for security in March 2000 does not applied manufacturing vehicles before in 2000. It has be prescribed in the regulations that incombustibles must be used. But detailed test standard related with incombustibles is not prescribe. Thus that regulation be required reinforcement of detailed test standard. Main cause of Dae-Gu subway accident is a fire in vehicle. However, many defects are found in infrastructure and operating vehicle of urban transit, such as inexperienced disposal of driver and CCC in early stage of the fire accident, unskilled opening and closing doors, insufficient escape facilities and safety facilities of a station house and tunnel, and incomplete communication system between vehicle and CTC, extraordinary step. Thus the aims of this study are prevention of urban transit accident, improvement plan of safety driving, and proposal of quick action plan through analysis of total faculty of vehicle.

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Conformity Assessment of Vertical Static Stiffness Test Method for Rail Pad (레일패드 정적 수직강성 시험방법의 적합성 평가)

  • Bae, Young-Hoon;Kim, Man-Cheol
    • Journal of the Korean Society for Railway
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    • v.18 no.1
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    • pp.33-42
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    • 2015
  • The vertical static stiffness of rail pads or baseplate pads, which are important components in rail fastening systems for track safety, is a key factor to determine the total track stiffness and a guideline of quality control in the manufacturing process. The vertical static stiffness can be checked by laboratory testing: test methods are EN 13146-9 and KRS TR 0014, which are widely used in the railway field. In this paper, to correct some problems, namely the preloading step, the unloading level, and the holding time in the loading program in the vertical static stiffness test of EN 13146-9 and KRS TR 0014, domestic and foreign test standards of pads were analyzed and then certain schemes for a vertical static stiffness test were proposed. To assess the reliability of the proposed schemes, the vertical static stiffness tests were performed with 4 pads and the validity of the test results was estimated.

A Review of Withering in the Processing of Black Tea

  • Deb, Saptashish;Jolvis Pou, K.R.
    • Journal of Biosystems Engineering
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    • v.41 no.4
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    • pp.365-372
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    • 2016
  • Purpose: Tea is the most frequently consumed drink worldwide, next to water. About 75% of the total world tea production includes black tea, and withering is one of the major processing steps critical for the quality of black tea. There are two types of tea withering methods: physical and chemical withering. Withering can be achieved by using tat, tunnel, drum, and trough withering systems. Of these, the trough withering system is the most commonly used. This study focuses on the different types of withering, their effect on the various quality attributes of tea, and other aspects of withering methods that affect superior quality tea. Results: During physical withering, tea shoots loose moisture content that drops from approximately 70-80% to 60-70% (wet basis). This leads to increased sap concentration in tea leaf cells, and turgid leaves become flaccid. It also prevents tea shoots from damage during maceration or rolling. During chemical withering, complex chemical compounds break down into simpler ones volatile flavor compounds, amino acids, and simple sugars are formed. Withering increases enzymatic activities as well as the concentration of caffeine. Research indicates that about 15% of chlorophyll degradation occurs during withering. It is also reported that during withering lipids break down into simpler compounds and catechin levels decrease. Improper withering can cause adverse effects on subsequent manufacturing operations, such as maceration, rolling, fermentation, drying, and tea storage. Conclusion: Freshly harvested leaves are conditioned physically and chemically for subsequent processing. There is no specified withering duration, but 14-18 h is generally considered the optimum period. Proper and even withering of tea shoots greatly depends on the standards of plucking, handling, transportation, environmental conditions, time, and temperature. Thus, to ensure consumption of high quality tea, the withering step must be monitored carefully.

Analysis of mixing ratio of lacquer and glue for lacquer drying in low relative humidity environment (상온저습 환경에서의 옻의 건조를 위한 옻과 교의 배합 분석 연구)

  • Kim, Eun-Kyung;Jeong, Se-Ri;Yu, Jae-Eun
    • 보존과학연구
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    • s.32
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    • pp.37-52
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    • 2011
  • This study investigates the hardening characteristics of the mixture lacquer and glue at room temperature. Diverse samples were made from manufacturing of glue to the adding ratio in sap of the lacquer tree. After the examination of moisture content of samples, it has been seen that there is no relation with glue's kinds or adding ratio, but only with contain level of moisture. The samples made with film shape in order to examine the drying time. Samples with isinglass needed for over three days and had smooth surface. However, samples mixed with animal glue dried within a day and had ripples on the surface because of fast drying rate. In addition, the samples with isinglass had slow change of colour in early step of drying and no colour difference after completely drying although it had significant changes to black oxide as soon as contact with air. In structural analysis with FT-IR showed that the carbonyl bond increased in the samples of mixed with glue, compared to raw lacquer and treated lacquer.

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Virtual Metrology for predicting $SiO_2$ Etch Rate Using Optical Emission Spectroscopy Data

  • Kim, Boom-Soo;Kang, Tae-Yoon;Chun, Sang-Hyun;Son, Seung-Nam;Hong, Sang-Jeen
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.464-464
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    • 2010
  • A few years ago, for maintaining high stability and production yield of production equipment in a semiconductor fab, on-line monitoring of wafers is required, so that semiconductor manufacturers are investigating a software based process controlling scheme known as virtual metrology (VM). As semiconductor technology develops, the cost of fabrication tool/facility has reached its budget limit, and reducing metrology cost can obviously help to keep semiconductor manufacturing cost. By virtue of prediction, VM enables wafer-level control (or even down to site level), reduces within-lot variability, and increases process capability, $C_{pk}$. In this research, we have practiced VM on $SiO_2$ etch rate with optical emission spectroscopy(OES) data acquired in-situ while the process parameters are simultaneously correlated. To build process model of $SiO_2$ via, we first performed a series of etch runs according to the statistically designed experiment, called design of experiments (DOE). OES data are automatically logged with etch rate, and some OES spectra that correlated with $SiO_2$ etch rate is selected. Once the feature of OES data is selected, the preprocessed OES spectra is then used for in-situ sensor based VM modeling. ICP-RIE using 葰.56MHz, manufactured by Plasmart, Ltd. is employed in this experiment, and single fiber-optic attached for in-situ OES data acquisition. Before applying statistical feature selection, empirical feature selection of OES data is initially performed in order not to fall in a statistical misleading, which causes from random noise or large variation of insignificantly correlated responses with process itself. The accuracy of the proposed VM is still need to be developed in order to successfully replace the existing metrology, but it is no doubt that VM can support engineering decision of "go or not go" in the consecutive processing step.

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Measuring of the Performance of a Construction Management Project from Viewpoints of Project Participants -Focusing on Owner, Construction Manager, Designer and Constructor- (건설사업 참여주체(발주자, CMr, 설계자, 시공자) 관점에서 건설사업관리 성과측정에 관한 연구)

  • Ahn, Eun-Jin;Yoo, Byeong-Gi;Lee, Yoon-Sun;Kim, Jae-Jun
    • Korean Journal of Construction Engineering and Management
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    • v.9 no.3
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    • pp.194-205
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    • 2008
  • The production process of construction industry is different from thing of the general manufacturing, likewise various participants make temporary teamwork for success of the project through sharing of information. But, the each role of participants is Individually changed to step in construction process stage and moreover it has complicated, entangled interests. The CM(so it called Construction Management as an abbreviation word) system was inducted for the effective management and operation of construction project. The key of the CM success depends on the cooperative relationship relation to major participants. There are lots of studies and efforts for the performance measures of the CM, however existing performance index is only measured as the viewpoint of project owner. Therefore it needs to make up for balanced view through combination of the four-way view of participants. In this study, we should search for cooperative relationship of project participants, and then we should suggest to define the difference of project in their viewpoints.