• Title/Summary/Keyword: Obstacles control

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Effects of Hole Transport Layer Using Au-ionic Doping SWNT on Efficiency of Organic Solar Cells

  • Min, Hyung-Seob;Jeong, Myung-Sun;Choi, Won-Kook;Kim, Sang-Sig;Lee, Jeon-Kook
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.434-434
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    • 2012
  • Despite recent efforts for fabricating flexible transparent conducting films (TCFs) with low resistance and high transmittance, several obstacles to meet the requirement of flexible displays still remain. Indium tin oxide (ITO) thin films, which have been traditionally used as the TCFs, have a serious obstacle in TCFs applications. SWNTs are the most appropriate materials for conductive films for displays due to their excellent high mechanical strength and electrical conductivity. Recently, it has been demonstrated that acid treatment is an efficient method for surfactant removal. However, the treatment has been reported to destroy most SWNT. In this work, the fabrication by the spraying process of transparent SWNT films and reduction of its sheet resistance by Au-ionic doping treatment on PET substrates is researched. Arc-discharge SWNTs were dispersed in deionized water by adding sodium dodecyl sulfate (SDS) as surfactant and sonicated, followed by the centrifugation. The dispersed SWNT was spray-coated on PET substrate and dried on a hotplate. When the spray process was terminated, the TCF was immersed into deionized water to remove the surfactant and then it was dried on hotplate. The TCF film was then was doped with Au-ionic doping treatment, rinsed with deionized water and dried. The surface morphology of TCF was characterized by field emission scanning electron microscopy. The sheet resistance and optical transmission properties of the TCF were measured with a four-point probe method and a UV-visible spectrometry, respectively. This was confirmed and discussed on the XPS and UPS studies. We show that 87 ${\Omega}/{\Box}$ sheet resistances with 81% transmittance at the wavelength of 550 nm. The changes in electrical and optical conductivity of SWNT film before and after Au-ionic doping treatments were discussed. The effects of hole transport interface layer using Au-ionic doping SWNT on the performance of organic solar cells were investigated.

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Analysis of EMI Between Overlapped Railway Signalling Systems and Its Countermeasure (철도신호시스템 중첩운영으로 인한 전자파장해현상 분석 및 대책)

  • Kho, Young-Hwan;Yoon, Sun-Ho;Choi, Kyu-Hyoung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.6
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    • pp.1116-1122
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    • 2009
  • ATS(Automatic Train Stop) system makes train stop when it runs over the speed limit and ensure the safe operation of train. Seoul Metro line 2 in Korea, which started its passenger service in 1982, has adopted ATS system for its signaling system. The ATS system has only a train stop function at the time of emergency, and Seoul Metro is planning to replaced them with ATC(Automatic Train Control)/ATO(Automatic Train Operation) system which can provide the dedicated speed control for headway reduction and automatic operation of train. Until all the ATS system is replaced with the new ATC system, both systems are to operate simultaneously at the same metro line. In this situation, ATS system sometimes reveals improper operation: train stops suddenly without any obstacles in front of it. These emergency stops cause interruption of passenger service, and abnormal abrasion of wheels and rail. This paper makes it clear that these interruptions are caused by EMI phenomena between ATS on-board device and ATC wayside device : Signal current flowing in AF track circuit of ATC is turn out to be a EMI source that prevent normal operation of the ATS on-board device. Although the two systems have different frequency-ranges (ATS system has frequency range between $78{\sim}130$[kHz] and ATC system has frequency range between $9.5{\sim}16.5$[kHz]), it turned out that EMI phenomena appears between the both systems. This is investigated by measuring the output signal from ATS on-board device passing over ATC wayside device. The FFT(Fast Fourier Transform) analysis of the signal reveals that AF track circuit signal is transmitted to the ATS on-board device and induce noise causing improper operation. The countermeasures to the EMI phenomena are examined in three ways; blocking EMI transmission, enforcement of EMS (Electromagnetic Susceptibility) of ATS on-board device, and blocking the EMI source. It is suggested that the practical solution be blocking EMI source temporarily, that is breaking AF track circuit signal when the trains with ATS on-board device pass over it. To this purpose, TODS(Train Occupation Detection System) is developed, and has made a success in preventing the EMI problem of Seoul Metro line 2.

Performance Improvement of Single Chip Multiprocessor using Concurrent Branch Execution (분기 동시 수행을 이용한 단일 칩 멀티프로세서의 성능 개선)

  • Lee, Seung-Ryul;Kim, Jun-Shik;Choi, Jae-Hyeok;Choi, Sang-Bang
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.2
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    • pp.61-71
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    • 2007
  • The instruction level parallelism, which has been used to improve the performance of processors, expose its limit. The change of a control flow by a branch miss prediction is one of the obstacles that restrict the instruction level parallelism. The single chip multiprocessors have been developed to utilize the thread level parallelism. However, we could not use the maximum performance of the single chip multiprocessor in case of executing the coded programs without considering the multi-thread. In order to overcome the two performance degradation factors, in this paper, we suggest the concurrent branch execution method that applies to the multi-path execution method at a single chip multiprocessor. We executes all two flows of the conditional branch using the idle core processor. Through this, we can improve the processor's efficiency with blocking the control flow termination by the branch instruction and reducing the idle time. We analyze the effects of concurrent branch execution proposed in this paper through the simulation. As a result of that, concurrent branch execution reduces about 20% of idle time and improves the maximum 10% of the branch prediction accuracy. We show that our scheme improves the overall performance of maximum 39% compared to the normal single chip multiprocessor and maximum 27% compared to the superscalar processor.

A Awareness Survey of HACCP Implementation in the Korean Slaughterhouses (도축장에서 HACCP 시행주체의 HACCP 운용수준 및 성공적 시행에 대한 인식실태)

  • 이영순;김용상;강경선
    • Journal of Food Hygiene and Safety
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    • v.17 no.1
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    • pp.45-54
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    • 2002
  • Hazard Analysis Critical Control Point System (HACCP) is recognized worldwide as a science-based and systematic approach for food safety. This has been initiated to establish the HACCP system in Korean slaughterhouses by suggesting some of effective implementation ways. An awareness level survey using questionnaire for 124 owners and 363 employees of the slaughterhouses, and 170 government officers responsible for HACCP duties was performed. This study shows that only 34.7% of owners, 21.1% of employees, and 57.1% of government officers have good understanding of HACCP, but 93.5%, 88.9% and 93.6% respectively have the willingness of HACCP implementation. Major benefits in HACCP implementation in the slaughterhouse raised by respondents were improvement of hygiene level of the plant (54.1%), increase of meat sale (17.6%), pride of the production of safe meat for human consumption (9.6%) and increase of meat export (7.5%), while major obstacles were financial difficulties (33.2%), poor levels of the facilities and equipments in the plants (27.3%), poor level of personal hygiene (19.4%), and lack of understanding of HACCP (12.3%). The most urgent measures which respondents raised to implement HACCP system effectively in the slaughterhouses at the moment were the Improvement of levels of facilities and equipments in the plants (36.6%), the establishment of HACCP base through education and training (19%), special benefits to HACCP implementing plant (11.8%), and close relationship between government and the industry (10.3%). The present study shows some of effective ways to implement HACCP in slaughterhouses.

Needs Assessment for Health and Nutrition Information of Korean Women through PC Communication (한국여성 건강 및 영양 정보시스템 구축을 위한 PC통신에 의한 정보 서비스 요구분석)

  • Kang, Nam-Mi;Hyun, Tai-Sun;Tack, Gye-Rae
    • Women's Health Nursing
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    • v.4 no.3
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    • pp.365-374
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    • 1998
  • Although the information related to health and nutrition continues to increase at an ever-increasing rate, systematic database which is necessary for self-management of woman health over the life cycle has been rarely found. The purpose of this study was to offer valuable information on woman health and nutrition through the computer, and, therefore, to enable Korean women to manage their health by themselves according to their life cycle, Prior to constructing the information system, a survey was conducted to verify the use and usefulness of the health information currently available through the PC communication and internet, and to identify the specific topics of the health and nutrition information Korean women need. A self-administered questionnaire was distributed through PC communication. The responses of 1,117 women were analyzed. Most of the subjects(72.8%) were at the age of twenties, and 14.6% at tens, 10.7% at thirties, and only 1.9% were over forties. The educational level of the subjects was high ; 44.8% were college graduates or above, 31.4% were college students. The greatest obstacles to the use of health information appeared to be the lack of expertise of the information on the PC communication and taking too much time to get information on the internet. The extent of the interest of the specific topic was determined by a 5-point scale. Out of the 22 topics of the health and nutrition information given on the questionnaire, stress management was ranked as the top over the whole range of age. The top three topics in which women had interests except stress management varied by age group ; diet for weight control and self-evaluation of the meal at the age of less than twenty-four ; health and nutrition management for preventing cancer and diet for weight control at the age of twenty-five to twenty-nine ; health and nutrition management for infants and children, and for preventing osteoporosis at the age of thirty to thirty-four ; health and nutrition management for preventing osteoporosis, and for preventing cancer at the age of over thirty-five. On the basis of these results an information system necessary to Korean women in order to manage their health by themselves according to the life cycle will be constructed through internet.

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Role, Change, Job Satisfaction and Obstacles in Carrying out the Role of Public Health Nurses in Health Center (보건소 보건간호사의 역할변화, 역할수행의 장애요인과 만족도)

  • Ahn, Kyeong-Sook;Jung, Moon-Sook
    • Journal of agricultural medicine and community health
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    • v.20 no.1
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    • pp.1-13
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    • 1995
  • Based on the questionnaires sent to 270 nurses of public health centers in kyungnam during the period of March 19 to April 11 in 1992, this study was written for the of finding out the grade of satisfaction, obstacles in carrying out duties concerned with nursing services and the change of nurses role needed according to the change of the local public health administration. The first-ranking tasks carried by nurses of public health center are believed to have been family planning activities before the 1970's, nursing services during the 1970's, mother-child health activities during the 1980's, and nursing services during the period of 1990 to 1992. As far as the priority order of all the family planning activities is concerned, the counseling of the insertion of intrauterine contraceptive device, the use of oral pill or the distribution of condom was placed emphasis on before 1970, and publicity activities of family planning after that time. The first priority order of mother-child health activities has been put on the registration of pregnant women since 1970, with prenatal examination and vaccination ranking next to it. The priority order for activities against tuberculosis was laid on finding out and registration of new T.B. patients every year, with patients' control, and medication or injection ranking next to it. As for the priority order of nursing services, traveling medical examination and treatment ranked the first-stressed activity before 1970, with medication and injection ranking next to it. The first priority order management activity of communicable diseases was put on vaccination before 1970, with medication and injection. ranking next. And consultation and education ranked second to it during 1990 to 1992. As for the health services of the aged, traveling examination and treatment ranked the order, with the assistance of medical examination ranking next to it. As far as troubles and obstacles shown in case of family planning, the rate of residents' lack understanding was 28.8%, that of lacking budget 13.6%, and the imperfection of public health administration system 11.9%. In the case of tuberculosis control, residents' lacking understanding was 32.5%, the deficiency of public health administration system 18.2%, over-duty(shortage of hands) 15.6%, and the insufficiency skill and know-how 13.0%. In the case of nursing services, the deficiency of public health administration system was 18.2%, each over-duty(the shortage of hands) and the shortage of facilities and equipment 15.6% respective, and residents' lacking understanding 13.0%. The rate of dissatisfaction with the chance or possibility of promotion for his or her career or capability was shown to be 49.2%, and 65.9% of the health nurses expressed their complaints of the deficiency of the chance of the promotion to a professional or expert. when the public health nurses were asked in the questionably whether they were satisfied or not with current state of equipment and facilities needed for public health service, 49.6% of them answered in the negative. The grade of the satisfaction with the current individual position was shown to be low as much as the status of his or her position was now. 37.6% of those asked in the research answered to have the readiness to switch jobs for the reasons of dissatisfaction and so on with lacking promotion chance as well as bad working condition. Significant correlation between the grade of job satisfaction and the current status of the po as found to be in this research, which showed that the lower the status of position was, the lower the grade of job satisfaction was. But little correlation between the grade of job satisfaction and his or her schooling and career was found. In order to carry out primary health care successfully, it can be said that more education and publicity activities to make public health nurses and residents see it in a new light are requested. In addition to it, it is suggested that the improvement of promotion system for public health nurses and the enlargement of job province should also be taken in consideration of the high dissatisfaction with and complaints of the chance of promotion and the system of position. In order words, it is important that considerations for system improvement enough to make nursing services pleasant and satisfactory should be taken into.

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Influences of Addition of Jellyfish Powder to Bed Soil and Bacterial Community Structure of Bed Soil (해파리 분말의 상토 첨가물로서의 효과 및 상토의 미생물 군집 변화에 대한 연구)

  • Beck, Bo-Ram;Choi, Jae-Ho;Kim, Young-Rok;Cha, Ha-Eun;Do, Hyung-Ki;Hwang, Cher-Won
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.2
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    • pp.227-234
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    • 2012
  • Recently, the population of toxic and/or unusable jellyfish is increasing during summer along the east coast of Korea, causing massive economical and ecological damage to fisheries, nuclear power plant and marine environment. To solve this problem, this study was carried out using jellyfish as a potential soil additive for horticulture. The jellyfish was solidified and homogenized, then mixed with a commercial bed soil. Allium tuberosum ROTH was planted to control bed soil (BS) and jellyfish powder mixed bed soil groups (Mixed bed soil, MBS), and following parameters were measured during five weeks: water content, electrical conductivity and growth of leaves. At the end of the experiment, bacterial community structures of each pot were analyzed by DGGE. The relative water adsorption of jellyfish powder was about 2.5 times greater compared to its dry weight. The water content of MBS group was significantly higher than BS group 6.5 to 14.2%, and the electric conductivity of MBS group was measured around 2.8 dS/m where BS group was resulted average of 1.8 dS/m. However, the leaves of BS group were grown 30% longer compared to MBS group. DGGE analysis of MBS group was shown in high number of phylum Bacteroidetes and increased diversity of Sphingobacteriia compared to BS group. Jellyfish powder as a soil additive surely will be a good candidate as humectant and microbiota stimulator, although there are several obstacles such as high electrical conductivity and residual alum salt which used for solidification of jellyfish.

Home hospice palliative care service in Korea: Based on focus group interview (가정 호스피스완화의료 서비스 현황 조사: 실무자 포커스 그룹 인터뷰를 중심으로)

  • Koh, Su-Jin;Kim, Yeol;Song, Mi Ok;Choi, Youngsim;Choi, Sung Eun;Jho, Hyun Jung;Huh, Yun Jung;Park, Myung-Hee;Park, Seon Ju;Kwon, So-Hi
    • Journal of the Korean Data and Information Science Society
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    • v.25 no.1
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    • pp.37-52
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    • 2014
  • The aim of this study was to understand home hospice care status and problem in Korea, and ultimately to develop the home hospice standard. This study was conducted as a part of a study on the institutionalization of the home hospice in Korea. A focus group interview with representatives of seven home hospice agency where have provided home hospice service for years was conducted. All of the participants agreed to the essential components for home hospice service including 24 hour on call service, multidisciplinary team visiting, and periodical team meeting. Visiting frequency was 1-3 times per week mostly by nurses. And they agreed requisitely to fulfill an office for home visiting nurses, storage space, and home visiting bags. The obstacles of providing home hospice were 1) no reimbursement system, 2) difficulties to change medication at home, 3) lack of inpatient beds for symptom control. Standardization of home hospice is critical to improve service quality and to develop reimbursement system. The findings of this study could be used as a basic data to develop home hospice standards and guidelines.

A Study on the Systemic Improvement for the Enactment and Revision of the National Fire Safety Code (국가화재안전기준(NFSC)의 제·개정 시스템 개선에 관한 연구)

  • Song, Young-Joo;Kim, Tae-Woo;Jeong, Keesin
    • Fire Science and Engineering
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    • v.34 no.2
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    • pp.110-119
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    • 2020
  • The National Fire Safety Code (NFSC) sets forth the installation methods and technical standards of firefighting facilities. This information is stipulated in the attached Table 1 of the Enforcement Decree of the Act on Fire Prevention and Installation, Maintenance and Safety Control of Fire-Fighting Systems. The NFSC serves as a foundation for fire prevention and public safety. However, the current version of the NFSC has been under scrutiny due to its delayed enactment and revision process. This is because of its structural inflexibility, time-consuming procedures, and mixed usage of both performance and technical standards. Furthermore, there are difficulties with keeping its unique specialties due to the absence of a specialized, permanent independent entity that enacts, revises, and maintains its standards. Moreover, the NFSC lacks collectivity, openness, and consistency. Therefore, to overcome the aforementioned obstacles, this study investigates the operational and legal status of the NFSC and the problems regarding its enactment and revision process. Further, it presents suggestions for system improvement by analyzing and comparing the information with domestic and foreign counterparts dedicated to managing their similar technical NFSC standards. First, the study recommends that the legal performance and technical standards mixed within the current NFSC should be separated. Second, the enactment and revision of technical standards should be implemented by the private sector and not by the government. Third, technical standards should adopt a user-oriented approach for the code system.

Analysis of Motivational Factors of Korean Women with Children to become Mumpreneurs (한국 주부 창업자의 창업 동기요인 분석)

  • Lee, Jae Hong;Lee, Bong Hwan
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.13 no.2
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    • pp.79-90
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    • 2018
  • A wide range of challenges and obstacles still exist for "mumpreneurs" in creating or developing their business ventures. It is important to investigate the factors regarding why many mothers choose to become self-employed and partially abandon the benefits offered by traditional employment. This study focus on the individual, but an implied positive relationship also exits between motivational factors and mumpreneurs in Korea. Thus, four factors in this study - push, pull, environmental, and financial factor - raise the practical implications regarding the motivational factors of women entrepreneurial challenges in Korea. This study's findings also consider the nature and changes of Korean mumpreneurs' motivational factors, their challenges, and attitudes as business owners in Korean labor markets. This study's findings suggest that a combination of push and pull factors could similarly trigger new business ownership. The empirical contrast in such variables as motivations or barriers to mumpreneurship, in realities provide a superior understanding of women's tendency or willingness toward business creation, as they struggle to survive in the Korean labor market. They tend to start their own businesses to gain more responsibilities in both work and their families, and want to manage their own lives to contribute as capable members of society. Therefore, any Korean mother, regardless of any industry-specific experience, wants to use entrepreneurship as a shortcut to satisfy her need for self-fulfillment. The general motivational factors for becoming a mumpreneur exist among both external and internal situations. The circumstances beyond their control, such as job termination or unemployment, compel these mothers into the workforce due to their responsibility toward their families, but they simultaneously dream of self-achievement and development. Most mumpreneurs in Korea also want to demonstrate their potential and achieve societal recognition as well as increase in property.