• 제목/요약/키워드: Long Life Test

검색결과 611건 처리시간 0.028초

A Study of the PV System for Optimum Design Methods With Loss Parameter Compensation

  • Lee, Kang-Yeon;Choi, Moon-Han;Choi, Youn-Ok;Joeng, Byeong-Ho;Cho, Geum-Bae
    • 조명전기설비학회논문지
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    • 제21권9호
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    • pp.64-75
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    • 2007
  • Photovoltaic systems utilize the infinite clean energy of the sun, without creating any air pollution or noise and mechanical vibration. A PV system operates without the need of fuel, rotation surfaces, high temperatures or high pressures. It is therefore to do maintain and simple to install as well as having a long life cycle. The global market for PV systems continues to grow rapidly by 30[%] per year. This paper suggests a new design method for the PV system installation that will allow to the improvement of system efficiency. This method is in accordance with the loss parameter compensation method designed for the PV systems and investigated through simulation and practical experimentation. It was applied to an interconnected 10[kW] grid PV system and was demonstrated in the field. Features such as solar array, PCS, system efficiency, performance and stability were considered. Through the proposed optimal parameter design method, the features of the system were studied, and the 10[kW] PV system was demonstrated and analyzed.

Inheritence, linkage and Possible Use of Fractured Starch Mutant in Barley (Hordeum Vulga L.)

  • Chung, Tae-Young
    • Journal of Plant Biotechnology
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    • 제3권3호
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    • pp.151-157
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    • 2001
  • In order to breed barley lines with reduced viscosity of wort, a fractured starch mutant of naked barley cultivar, Nubet, was obtained from the M2 seeds mutated by the diethyl sulfate treatment. Seeds of this fractured starch mutant were opaque and the endosperm consists of angular, irregular and fractured starch. The mutant was caused by single recessive mutation and assigned by the symbol fra. The gene was located on chromosome 4, distal in long arm by linkage recombinations using translocation homozygote lethal test set. The linkage value between the fractured starch mutant and 72-4a, 72-4d were 26.0$\pm$4.9, 34.2$\pm$3.1 percent respectively. In addition to the reduced seed size, fewer kernels per spike and higher tillering ability, lower $\beta$-glucan viscosity and higher lysine content of the grain were associated with this mutant. $\beta$-glucan viscosity of the Nubet grains increased from 3 weeks after anthesis to matury and most of the viscose substances appeared to be stored in the middle of the endosperm tissue. Since the mutant grains showed better milling property as compared to Nubet, it can be used as breeding resources to develope new barley cultivars for maltins and milling purpose.

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Turn signal lamp jacket to prevent accident of bicycles

  • Saxena, Tarika
    • 한국인공지능학회지
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    • 제4권1호
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    • pp.4-7
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    • 2016
  • These days, citizens have made change of food life to take Western style food and to suffer from diabetes because of excessive nutrition taking, less exercise, stress and other environmental factors. They may suffer from diabetes because of genetic defect, surgery of pancreas, disinfection and medicine and others. One of ten Koreans may have symptom of diabetes to be popular. The diabetes that is a kind of metabolic disease has high blood sugar at disorder of hyper insulinism and/or defect of insulin action. Long time high blood sugar may produce chronic disease of kidney, eyes, nerve, heart and blood vessel and others. The purpose of health care of diabetes patient was to reach target blood sugar by diet, physical exercise and medicine and to prevent and delay complication. Diabetes patient shall control blood sugar to keep healthy. The blood sugar control requires time and effort, and all of the patients are difficult to make effort and to spend time. You can control blood sugar by the application. The application allows patients to control blood sugar and to save time and efforts and to make small sized input and automation of remaining area. The service was limited to blood sugar graph, and user carries smart phone to conduct test and to have difficulty. Further study needs to solve the problems and to investigate blood sugar testing not carrying smart phone and to make application of easy control of blood sugar.

A Study on the Determinants of Social Welfare: Evidence from Macroeconomics

  • He, Yugang;Feng, Wang
    • 산경연구논집
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    • 제9권9호
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    • pp.7-14
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    • 2018
  • Purpose - Social welfare is a social insurance system that provides funds and services for all citizens to maximize their life quality. Its ultimate goal is to alleviate social contradictions. Therefore, this paper explores the determinants of social welfare in terms of macroeconomics. Research design, data, and methodology - Based on the vector error correction model, the annual time series from 1990 to 2017 will be used to conduct an empirical analysis. The real GDP, the real income, the inflation and the degree of openness will be treated as independent variables. The input of social welfare will be treated as a dependent variable. These variables will be used to perform the cointegration test and the vector error correction model to explore how the macroeconomic variables affect social welfare both in long run and short run. Result - Via the empirical analysis, it can be summarized that the real GDP, the real income and the degree of openness are the driving determinants to enlarge the social welfare. Conversely, the inflation is the obstructive determinant to reduce the social welfare. Conclusion - The positive and negative determinants of social welfare exist simultaneously, China's government should take macroeconomic regulation and control to balance them to enlarge social welfare.

Morphological Characteristics of Bambusa vulgaris and the Distribution and Shape of Vascular Bundles therein

  • Darwis, Atmawi;Iswanto, Apri Heri
    • Journal of the Korean Wood Science and Technology
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    • 제46권4호
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    • pp.315-322
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    • 2018
  • Bamboo culm comprises internodes and nodes and is tapered from the bottom to the top. Anatomically, bamboo culm comprises vascular bundles and parenchymal base tissue. The gross anatomical structure of a transverse section of any culm internode is determined by the shape, size, arrangement, and number of vascular bundles. The purpose of this research was to examine the morphology of culm and the distribution and shape of vascular bundles in Ampel bamboo (Bambusa vulgaris). Bamboo culms were harvested from the base. Test samples were obtained from a central 2-cm long segment of each internode across the entire length of the culm. Results showed an uneven spread of vascular bundles in the internode cross-section. Transitioning from the outer to the inner layer of the internode, the number of vascular bundles per unit area decreased and their shape was variable. The size of vascular bundles in the middle layer of the internode was greater than that of those in the outer and inner layers. The shape of vascular bundles was circular in the outer layer, which gradually transformed into vertical oval toward the middle layer and horizontal oval toward the inner layer. Vascular bundles were of type III and IV in the bottom of the culm and type III in the middle to the top of the culm.

Evaluation of a Community Health Practitioner Self-care Program for Rural Korean Patients with Osteoarthritis

  • Lee, Chung Yul;Cho, Yoon Hee
    • 대한간호학회지
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    • 제42권7호
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    • pp.965-973
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    • 2012
  • Purpose: The purpose of this study was to evaluate a self-care program for elders with osteoarthritis managed by primary health care workers, Community Health Practitioners (CHPs), in rural Korea. Methods: The self-care program, consisting of 7 areas, was evaluated with a randomized experimental study for patients over age 60 with osteoarthritis in which 150 participants in the experimental group and 140 in the control group were compared. The self-care program was implemented for six weeks, 2 hours per week, at community health posts by CHPs. Data were collected using an interview questionnaire given by the CHPs and laboratory tests before and after the intervention for both groups. Propensity score matching analysis was done to test effectiveness after controlling for confounding variables. Results: The intervention group showed a significant decrease in the number of painful joints (p<.001) and a significant increase in self-care ability (p<.05) compared to the control group. Conclusion: Study results indicate that training and utilizing primary health care workers in rural areas is valuable in increasing the generalization and continuity of intervention programs. As arthritis should be managed life-long, CHP directed self-care programs are useful interventions for rural elders with arthritis to learn self-care management.

SL 무기질 바닥재의 경제성 분석에 관한 연구 (A study on the economic analysis of the SL(Self Leveling) Inorganic Floor covering)

  • 박호근;홍성욱;양재영;김상원;신찬호;최민권
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2011년도 춘계 학술논문 발표대회 2부
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    • pp.105-109
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    • 2011
  • This study is concerned with the development of the SL inorganic floor covering. First, volatile organic compounds, inorganic test profile on the SL through the flooring is environment-friendly inorganic noncombustible floor finishes the event of fire toxic gases (such as volatile organic compounds) emissions have been identified as not at all. Second, SL-breathable material, the concrete floor to prevent aging, long life, which are three levels of noise, shock-absorbing function was decreased. Third, SL economic analysis of mineral flooring terrazzo tile floors compared with the normal material. On a terrazzo tile cost 13,500 won ~ 24,500 won, but It have found that, in terms of labor SL 36,899 won ~ 38,899 won flooring mineral balance. Occurs in the total amount when compared with terrazzo tile floors and 25,399 won 3T, 5T and economical analysis concludes that the original 12,399 won.

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국내 LED 조명등에서 플리커 현상에 관한 연구 (A Study on the Condition of LED Lights Flicker)

  • 허민;고재준;김충혁
    • 한국전기전자재료학회논문지
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    • 제29권11호
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    • pp.729-735
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    • 2016
  • It is highly important issue to use an energy efficiently for sustainable prosperity of mankind. From this point of view, using LED lighting can be a good alternative because it has a lot of advantages such as high efficiency, long life time and eco-friendly manufacturing process. That is the reason why using LED lighting has been encouraged worldwide. However, in situations that LED lighting is replacing traditional lighting quickly, the problem of the flicker of LED lighting has emerged as an important issue. Therefore, in foreign countries like US or Japan in order to ensure the reliability of LED lighting, study for flickering effects of the human body and test methods are have been actively conducted. But related research in domestic situation is an insufficient condition. In this study, a flicker characteristic was measured conventional lamps such as incandescent lamps or fluorescent lamp and 81 items of LED lightings which are distributed in domestic markets.

Physical and Mechanical Properties of Cementitious Specimens Exposed to an Electrochemically Derived Accelerated Leaching of Calcium

  • Babaahmadi, Arezou;Tang, Luping;Abbas, Zareen;Martensson, Per
    • International Journal of Concrete Structures and Materials
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    • 제9권3호
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    • pp.295-306
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    • 2015
  • Simulating natural leaching process for cementitious materials is essential to perform long-term safety assessments of repositories for nuclear waste. However, the current test methods in literature are time consuming, limited to crushed material and often produce small size samples which are not suitable for further testing. This paper presents the results from the study of the physical (gas permeability as well as chloride diffusion coefficient) and mechanical properties (tensile and compressive strength and elastic modulus) of solid cementitious specimens which have been depleted in calcium by the use of a newly developed method for accelerated calcium leaching of solid specimens of flexible size. The results show that up to 4 times increase in capillary water absorption, 10 times higher gas permeability and at least 3 times higher chloride diffusion rate, is expected due to complete leaching of the Portlandite. This coincides with a 70 % decrease in mechanical strength and more than 40 % decrease in elastic modulus.

플라스틱 배관의 접합 조건에 관한 연구 (A Study of Welding Conditions for Plastic Piping)

  • 이철구;이우람;박철양
    • 한국생산제조학회지
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    • 제20권5호
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    • pp.564-569
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    • 2011
  • The current establishment of city gas piping polyethylene (PE) tube used as bonding state or part of the health or safety of fusion is very important. A part of these fusion methods to determine the soundness of the short-term trials and long-term tests can be largely classified. Typical tests include short-term strength, tensile strength, impact strength, compressive strength, resiliency and compression. Polyethylene (PE) pipes installed in the domestic terms of overall penetration rate of 45% has been used. However, polyethylene (PE) pipes have reliability problems, and these occurs mostly in part by defective welding. Therefore, the test is necessary for safety. Non-destructive methods (ultrasonic testing) are difficult to be used. Therefore, Polypropylene copolymer (PP-C), polypropylene homopolymer (PP-H), and polyethylene (PE) pipe are used. Fusion of these materials is necessary in these field however, its technical, and basic research has not been studied well. In this research, short-term strength of welding parts, its tensile strength, hardness, fatigue, and microstructure have been analyzed to find the optimum process conditions to improve mechanical properties.