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Effects of Substrate Temperature on the Microstructure and Photoluminescence Properties of ZnO Thin Films by Atomic Layer Deposition (ZnO 성장을 위한 Atomic Layer Deposition법에서 공정온도가 박막의 구조적 및 광학적 특성에 미치는 영향)

  • Lim, Jong-Min;Lee, Chong-Mu
    • Korean Journal of Materials Research
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    • v.15 no.11
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    • pp.741-744
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    • 2005
  • Atomic layer deposition (ALD) is a very promising deposition technique for ZnO thin films. However, there have been very few reports on ZnO grown by ALD. Effects of substrate temperature in both ALD and post annealing on the microstructure and PL properties of ZnO thin films were investigated using X-ray diffraction, photoluminescence, and scanning electron microscopy. The temperature window of ALD is found to be between $130-180^{\circ}C$. The growth rate of ZnO thin film increases as the substrate temperature increases in the temperature range except the temperature window. The crystal quality depends most strongly on the substrate temperature among all the growth parameters of ALD. The crystallinity of the film is improved by increasing the growth thine per ALD cycle or doing post-annealing treatment. The grain size of the film tends to increase and the grain shape tends to change from a worm-like longish shape to a round one as the annealing temperature increases from $600^{\circ}C\;to\;1,000^{\circ}C$.

The Analysis of Changma Structure using Radiosonde Observational Data from KEOP-2007: Part I. the Assessment of the Radiosonde Data (KEOP-2007 라디오존데 관측자료를 이용한 장마 특성 분석: Part I. 라디오존데 관측 자료 평가 분석)

  • Kim, Ki-Hoon;Kim, Yeon-Hee;Chang, Dong-Eon
    • Atmosphere
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    • v.19 no.2
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    • pp.213-226
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    • 2009
  • In order to investigate the characteristics of Changma over the Korean peninsula, KEOP-2007 IOP (Intensive Observing Period) was conducted from 15 June 2007 to 15 July 2007. KEOP-2007 IOP is high spatial and temporal radiosonde observations (RAOB) which consisted of three special stations (Munsan, Haenam, and Ieodo) from National Institute of Meteorological Research, five operational stations (Sokcho, Baengnyeongdo, Pohang, Heuksando, and Gosan) from Korea Meteorological Administration (KMA), and two operational stations (Osan and Gwangju) from Korean Air Force (KAF) using four different types of radiosonde sensors. The error statistics of the sensor of radiosonde were investigated using quality control check. The minimum and maximum error frequency appears at the sensor of RS92-SGP and RS1524L respectively. The error frequency of DFM-06 tends to increase below 200 hPa but RS80-15L and RS1524L show vice versa. Especially, the error frequency of RS1524L tends to increase rapidly over 200 hPa. Systematic biases of radiosonde show warm biases in case of temperature and dry biases in case of relative humidity compared with ECMWF (European Center for Medium-Range Weather Forecast) analysis data and precipitable water vapor from GPS. The maximum and minimum values of systematic bias appear at the sensor of DFM-06 and RS92-SGP in case of temperature and RS80-15L and DFM-06 in case of relative humidity. The systematic warm and dry biases at all sensors tend to increase during daytime than nighttime because air temperature around sensor increases from the solar heating during daytime. Systematic biases of radiosonde are affected by the sensor type and the height of the sun but random errors are more correlated with the moisture conditions at each observation station.

Analysis of Cognition Pattern of a College Student's Occupational View on Social Welfare Position (사회복지사직에 대한 사회복지학과 학생의 인식유형)

  • Oh, Yun-Sou;Jung, Hyun-Tae;Lee, Seong-Dae
    • The Journal of the Korea Contents Association
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    • v.14 no.9
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    • pp.285-297
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    • 2014
  • This research is involved in looking into the cognition pattern of social worker position of a fourth-year student majoring in Social Welfare. The purpose of this research is to offer a basic data needed for education of the students who are preparing to get a job of a social worker. For this, applying Q methodology, this research made an objective analysis of their subjective response to social worker position targeting the 30 students in the department of social welfare at the four-year-course college located in Gyeongsangbuk-do and Gyeongsangnam-do. The research results showed that the cognition pattern of the college students' occupational view on social welfare position could be categorized into the three; The first pattern is a "job-skeptic & reality-evasive" type, who tends to perceive the position of a social worker as the one having a lot of job exhaustion and much workload, showing a pessimistic view on the meaning or a sense of mission of a social worker position. The second pattern is a "practice-centered & specialized-job-seeking type" who tends to think much of practical aspects of a social worker job and to seek after the position of a social worker as a specialized job, and at the same time to rely on the policy or system for a social worker position. The third pattern is a "value-oriented & self-achievement type", who tends to think much of the necessity of value or ethics in putting social welfare into practice and also to make much of self-achievement through the channel of a social welfare worker position. Taken together, it might be possibile to turn out professional human resources, but this research thinks it is more necessary to place the education of values of a social welfare worker.

A Study of the Equilibrium Result Index of Franchise Head Office (프랜차이즈본부(本部)의 균형성과지표개발(均衡成果指標開發)에 관한 연구(硏究))

  • Lee, Sang-yoon
    • Journal of Distribution Science
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    • v.3 no.1
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    • pp.69-90
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    • 2005
  • In research of a paper, the comparative study of the various precedence management result evaluation indices tends to be made, and it is going to show the improvement bill of the new franchise headquarters management result evaluation index by the equilibrium result table which compensated the problem stated from the contents of precedence research about the existing franchise management result evaluation index, and was corrected.

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Reliability Issue in LOC Packages

  • Lee, Seong-Min
    • Proceedings of the Materials Research Society of Korea Conference
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    • 1995.11a
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    • pp.3-3
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    • 1995
  • Plastic IC encapsulation utilizing lead on chip(LOC) die attach technique allows higher device density per unit package area, and faster current speed and easter leadframe design. Nevertheless, since the top surface of the chip is directly attached to the area of the leadframe with a double-sided adhesive tape in the LOC package, it tends to be easily damaged by the leadframe, leading to limitation in its utilization. In this work, it is detailed how the damage of the chip surface occurs, and it is influenced and improved by the LOC construct.

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A Multi-Resource Leveling Algorithm for Project Networks

  • Lee, Chung-Ung
    • Journal of the military operations research society of Korea
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    • v.3 no.1
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    • pp.123-136
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    • 1977
  • This thesis presents a modification and extension to the Burgess and Killebrew heuristic resource leveling procedure for project networks. In contrast to previous algorithms appearing in the literature, the objective function of this algorithm. is the minimization of the sum of the squared errors in each time period (deviations around the mean usage) of all resources over the duration of the project. This objective function continues the search for an improved schedule beyond that of previous algorithms with their associated objective functions. One important feature is that the algorithm tends to reduce the number of periods that a resource is idle during its duration on the project.

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A Model Design on the Korean AGT System (한국형 경량 전철 모델 연구)

  • 최출헌;한석윤;신학수
    • Proceedings of the KSR Conference
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    • 2001.05a
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    • pp.114-122
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    • 2001
  • As of these, the exterior design of the public transportation systems, especially electric multiple, tends to mimic advanced country's design rather than design of car shape reflecting cultural and spiritual background. However, in the new transportation system, the design which satisfies the transportation demand must be changed into the design which creates transportation demand. In this respect, this research focuses on the factor's embodiment which is perceived by Korean passenger sympathetic to cultural and spiritual needs. The results of this research are Korean AGT design on rubber tire AGT, steel wheel AGT, LM AGT system and environmental design related to AGT systems.

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A Conceptual Study on Outsourcing Strategy in Betel Industry (관광호텔 아웃소싱 전략에 관한 개념적 고찰)

  • 정연홍;하용규
    • Culinary science and hospitality research
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    • v.8 no.3
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    • pp.123-146
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    • 2002
  • Outsourcing is procuring of outside resources, other than core resources for core competence, by a contract, from which a corporate can focus its core resources on core business. The outsourcing strategies of Korea tourist hotel business are in a rudimentary stage, which has been limited in simple work areas such as housekeeping services, room maid services, parking control services, security services, janitor services, laundry services, facility management, shuttle bus services, and sterilization services and their purposes are mainly to retrench a burden of employment or firm-fixed expenses. Therefore, the outsourcing strategies of Korea tourist hotel business have the following problems. First, their outsourcing has introduced only for the purpose of retrenching expenses. Second, it tends to deteriorate service quality, due to lack of pre-training. Third, it tends to concentrate their attentions only on simple repetition works. Fourth, their outsourcing is slow adjusted to the needs of business cultures. Outsourcing services in Korea tourist hotel business have never contributed to their basic concepts such as 1) maintenance or enhancement of core competences, 2) promotion of business efficiency through service quality improvement and expense retrenchment, and 3) achievement or enhancement of competitive advantage through enlarging their specialties, cultivating their market, learning new knowledge, and developing their asset. Therefore, this study is to insist on fife necessity of overcoming simple repetitive service outsourcing in tourist hotel business. In order to build a core competence and/or achieve a competitive advantage, the scopes of outsourcing services should be enlarged in Korea tourist hotel business.

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100 MWe Oxyfuel Power Plant Boiler System Process Design and Operation Parameters Sensitivity Analysis (100 MWe급 순산소연소 발전소 보일러계통 공정설계 및 운전변수 민감도 예측)

  • Baek, Sehyun;Ko, SungHo
    • Journal of the Korean Society of Combustion
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    • v.18 no.4
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    • pp.1-11
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    • 2013
  • The oxy-fuel combustion is $CO_2$ capture technology that uses mixture of pure $O_2$ and recirculated exhaust as oxidizer. Currently some Oxy-fuel power plants demonstration project is underway in worldwide. Meanwhile research project for converting 125 MWe Young-Dong power plant to 100 MWe oxy-fuel power plants is progress. In this paper, 1 D process analytical approach was applied for conducting process design and operating parameters sensitivity analysis for oxy-fuel combustion of Young-Dong power plant. As a result, appropriate gas recirculation rates was 74.3% that in order to maintain normal rating superheater, reheater steam temperature and boiler heat transfer patterns. And boiler efficiency 85.0%, CPU inlet $CO_2$ mole concentration 71.34% was predicted for retrofitted boiler. The oxygen concentration in the secondary recycle gas is predicted as 27.1%. Meanwhile the oxygen concentration 22.4% and moisture concentration 5.3% predicted for primary recycle gas. As the primary and secondary gas recirculation increases, then heat absorption of the reheater is tends to increases whereas superheater side is decreased, and also the efficiency is tends to decrease, according to results of sensitivity analysis for operating parameters. In addition, the ambient air ingression have a tendency to lead to decline of efficiency for boiler as well as decline of $CO_2$ purity of CPU inlet.

Modeling Coordinated Contracts for a Supply Chain Consisting of Normal and Markdown Sale Markets

  • Lee Chang Hwan
    • Management Science and Financial Engineering
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    • v.11 no.1
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    • pp.1-24
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    • 2005
  • The results of a study of the coordination effect in stocking and promotional markdown policies for a supply chain consisting of a retailer and a discount outlet (DCO) are reported here. We assume that the product is sold in two consecutive periods: the Normal Sales Period (NSP) and the subsequent Promotional Markdown Sales Period (PSP). We first study an integrated supply chain in which managers in the two periods design a common system so as to jointly decide the stocking quantities, markdown time schedule, and markdown price to maximize mutual profit. Next, we consider a decentralized supply chain. An uncoordinated contract is designed in which decisions are decentralized to optimize the individual party's objective function. Here, three sources of system inefficiencies cause the decentralized system to earn a lower expected system profit than that in the integrated supply chain. The three sources are as follows: in the decentralized system the retailer tends to (1) stock less, and (2) keep a longer sales period, and the DCO tends to (3) stock fewer leftovers inventories and charge a higher markdown price. Finally, a numerical experiment is provided to compare the coordinated model with the uncoordinated model to explore factors that make coordination an effective approach.