• Title/Summary/Keyword: Knowledge Transfer Behavior

Search Result 34, Processing Time 0.04 seconds

Temperature Behavior of Superconducting Fault Current Limiters during Quenches (퀜치 시 초전도 한류기의 온도)

  • Kim H.-R.;Sim J.;Hyun O.-B.
    • Progress in Superconductivity
    • /
    • v.6 no.2
    • /
    • pp.108-112
    • /
    • 2005
  • We investigated temperature behavior of superconducting fault current limiters (SFCLs) during quenches. Knowledge on temperature behavior during quenches is important to the design of SFCLs, because the temperature of SFCLs is related to their stability. SFCLs were fabricated by patterning $Au/YBa_2Cu_3O_7$ thin films grown on sapphire substrates into meander lines by photolithography. A gold film grown on the back side of the substrate was patterned into a meander line, and used as a temperature sensor. The front meander line was subjected to simulated AC fault currents, and the back line to DC current. They were immersed in liquid nitrogen during the experiment for effective cooling. Overall, temperature at the back side of SFCLs was close to that at the front side. It was closer at the beginning of faults, and at lower applied voltages. Temperature distribution at the back side was even except at the edge, as at the front side. These results tell that the whole SFCL was heated to similar degree during quenches, and that effective cooling of SFCLs at the back side is as important to the stability of SFCLs as at the front side. The results could be explained with the concept of heat transfer within the film.

  • PDF

Analysis of Particles Motion in Vertical Rayleigh Flow (수직 Rayleigh 유동내의 입자 거동 해석)

  • Ko, Seok-Bo;Jun, Yong-Du;Lee, Kum-Bae
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.19 no.6
    • /
    • pp.447-456
    • /
    • 2007
  • Suspended particles behavior when they go through a vertical riser with heat transfer is of significant concern to system designers and operators in pneumatic transport, various processes such as in chemical, pharmaceutical and food industries. When it comes with the energy system, that knowledge is critical to the reliable design practices of related equipment as heat exchangers, especially in the phase of system scale-up. Without haying a good understanding of the related physics, many scale-up practices based on their pilot plant experience suffer from unexpected behaviors and problems of unstable fluidization typically associated with excessive pressure drop, pressure fluctuation and even unsuccessful particle circulation. In the present study, we try to explain the observed phenomena with related physics, which may help understanding of our unanswered experiences and to provide the designers with more reliable resources for their work. We selected hot exhaust gas with solid particle that goes through a heat exchanger riser as our model to be considered. The effect of temperature change on the gas velocity, thermodynamic properties, and eventually on the particles motion behavior is reviewed along with some heat transfer analyses. The present study presents an optimal riser length at full scale under given conditions, and also defines the theoretical limiting length of the riser. The field data from the numerical analysis was validated against our experimental results.

Determination of reaction kinetics during vitrification of radioactive liquid waste for different types of base glass

  • Suneel, G.;Rajasekaran, S.;Selvakumar, J.;Kaushik, Chetan P.;Gayen, J.K.;Ravi, K.V.
    • Nuclear Engineering and Technology
    • /
    • v.51 no.3
    • /
    • pp.746-754
    • /
    • 2019
  • Vitrification of radioactive liquid waste (RLW) provides a feasible solution for isolating radionuclides from the biosphere for an extended period. In vitrification, base glass and radioactive waste are added simultaneously into the melter. Determination of heat and mass transfer rates is necessary for rational design and sizing of melter. For obtaining an assured product quality, knowledge of reaction kinetics associated with the thermal decomposition of waste constituents is essential. In this study Thermogravimetry (TG) - Differential Thermogravimetry (DTG) of eight kinds of nitrates and two oxides, which are major components of RLW, is investigated in the temperature range of 298-1273 K in the presence of base glasses of five component (5C) and seven component (7C). Studies on thermal behavior of constituents in RLW were carried out at heating rates ranging from 10 to $40\;K\;min^{-1}$ using TG - DTG. Thermal behavior and related kinetic parameters of waste constituents, in the presence of 5C and 7C base glass compositions were also investigated. The activation energy, pre-exponential factor and order of the reaction for the thermal decomposition of 24% waste oxide loaded glasses were estimated using Kissinger method.

A Study on Real time Multiple Fault Diagnosis Control Methods (실시간 다중고장진단 제어기법에 관한 연구)

  • 배용환;배태용;이석희
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1995.04b
    • /
    • pp.457-462
    • /
    • 1995
  • This paper describes diagnosis strategy of the Flexible Multiple Fault Diagnosis Module for forecasting faults in system and deciding current machine state form sensor information. Most studydeal with diagnosis control stategy about single fault in a system, this studies deal with multiple fault diagnosis. This strategy is consist of diagnosis control module such as backward tracking expert system shell, various neural network, numerical model to predict machine state and communication module for information exchange and cooperate between each model. This models are used to describe structure, function and behavior of subsystem, complex component and total system. Hierarchical structure is very efficient to represent structural, functional and behavioral knowledge. FT(Fault Tree). ST(Symptom Tree), FCD(Fault Consequence Diagrapy), SGM(State Graph Model) and FFM(Functional Flow Model) are used to represent hierachical structure. In this study, IA(Intelligent Agent) concept is introduced to match FT component and event symbol in diagnosed system and to transfer message between each event process. Proposed diagnosis control module is made of IPC(Inter Process Communication) method under UNIX operating system.

  • PDF

A study on the awareness of oral health behavior and oral health education for a middle schools and high schools in Busan, Gyeongnam province (부산·경남 일부 중고등학생의 구강보건행동 및 구강보건교육경험 인지도에 관한 연구)

  • Jang, Kyeung-Ae
    • Journal of Korean society of Dental Hygiene
    • /
    • v.8 no.1
    • /
    • pp.107-118
    • /
    • 2008
  • The purpose of this study was to transfer the knowledge of oral health care and to improve the oral health after the effective education of oral health behavior. The survey is conducted for 484 middle and high school students in Busan and Gyeongnam province about the oral health behavior, the cause and the preventive of oral diseases and oral health education experience by the self-answering method. The date was analysed using the SPSS 13.0 program. The obtained result were as follows. 1. 38.8% students in middle school have been to the dentist within one year and the reason is the dental care that is to 61.7% in the case of the high school students. 2. For the daily toothbrushing frequency. above 3 times is highest to 57.9% in middle school students and 2 times 59.9% in high school students. 3. 45.9% and 45.0% students in middle and high school have the regular dental check-ups to prevent the dental caries and periodontal disease with greatest portion. 4. 35.7% respondents had experienced oral health education. 48% of them got the education from the dental clinics. 82.2% of the education method is a theory and the contents is toothbrushing method with 58.7% portion. 5. 86% respondents of middle school students answered that regular oral health education is necessary and 78.1% students are willing to participate in the oral health education. The results of this study propose that the regular dental check-ups for middle and high school students enable them have early medical treatment and protection against oral disease. Also for the effective oral health education, those program and various media should be developed systematically to enhance the students' motive for oral health.

  • PDF

Characterization of Thermal Properties of Concrte and Temperature Prediction Model (콘크리트재료의 열특성 및 수화열 해석)

  • 양성철
    • Magazine of the Korea Concrete Institute
    • /
    • v.9 no.2
    • /
    • pp.121-132
    • /
    • 1997
  • The thermal behavior of' concrete can be ch;lracterized from a knowledge of concrete ternperatu1.e at early ages, environmental conditions, and cement hydration in the mixture. 'l'o account for thost. interactions, a computer model was developed for prwlicting the temperature pr.ol'ile in hnrdcning c o n c r c t ~ st.r~icture in terms of material and tmvironmcntal factors. The cerncnt hydration cha~.acteristics such as the activating energy, total heat 1ihei.atr.d. anti th\ulcorner degree of' hydration. can represent the internal heat gc,neration. In this study. th(> activating c1ncrgy and the tlcgree of' hydration curve were determined well fmm the rnortn~. compressive strength tests while total amount of heat liberated was determined by tht> isothermal calorimctcr method. The main purpose of' this study is to correlate measured tt>mperaturr distributions in a concrete st1,ucture during thc hardening process with the ~ c s u l t s computed f'ro~n theoretical considrl.ations. Using twodimensional heat transfer model, first. the importance of several parameters will be identified by a parametric analysis. Then, the tcmpcmture distribution of thc cylindrical concrete specimen in the laboratory was mensuwti and compared with that yielded by thc theoretical considel.ations.

A Study on Drug Abuse and the Factors Affecting Drug Abuse Behaviors of Students Preparing College Entrance or Transfer Examinations (대입 재수생 및 편입준비생의 약물남용 실태와 이에 영향을 미치는 요인)

  • 조태현;남철현
    • Korean Journal of Health Education and Promotion
    • /
    • v.17 no.2
    • /
    • pp.57-73
    • /
    • 2000
  • A study on drug abuse of young people who failed in college entrance examinations and preparing the next examination and those enrolled at colleges but trying to transfer to other colleges was conducted from February 3 to May 31, 1999 in order to determine current drug abuse status of them and factors affecting their behavior related to drug abuse. A total of 1,771 people were selected from college entrance preparation institutes in Seoul, Pusan, Taegu, Taejon and Kwangju and interviewed by using questionnaires. The results are summarized as follows; 1. 49.78% of them experienced drinking, 22.8% smoking, and 6.7% drug previously. More males smoked cigarettes than females. The young in the age group of 25 to 29 years old, and the young living in small towns, and subjects who finished junior colleges and those without religions drank more than those in other categories. The subjects in the age group of 20 to 24 years old and those with one parent, and those living in small towns used more drugs than those in other categories. 2. 60.1% of those with drug using experience used the drug in their or friends' homes. 53.6% of them used drugs with their friends, junior or senior classmates. 36.6% of them purchased drugs from drug stores. 76.0% of them spent their pocket money for buying drugs. 3. The drugs (excluding alcohol and tobacco) they used were bond and butane gas (29.6%), stimulants (20.6%), marijuana 02.0%) LSD (4.8%), cocaine, heroine and opium (4.2%), and others (28.8%). 4. 21.5% of those with drug using experience had detoxification treatment previously. The ajmor sufferings they experienced were distraction (42.6%), fear 01.7%), and others. 5. 51.0% of the subjects experienced drug related health education in schools, and 14.6% had that kind of education through social program. 6. 64.3% of the subjects got information about drug abuse through mass media, 16.4% through printed materials, and 11.4% through public health professionals. 7. The knowledge level of drug abuse was 16.48:1:2.76 points out of 24 (68.6 points out of 100).

  • PDF

Model Development of an Elderly Health Promotion Center: The Effect of a Social Support Program at a Community Health Center (노인 건강증진센터 모형개발을 위한 연구: 일 지역보건소에 적용한 사회적지지 프로그램의 효과)

  • 박오장;소향숙
    • Journal of Korean Academy of Nursing
    • /
    • v.34 no.5
    • /
    • pp.781-790
    • /
    • 2004
  • Purpose: The purpose of this study was to develop a model of an elderly health promotion center after witnessing the effect of a social support program on dependent variables in older adults at a local community health center. Method: The subjects were 60 female adults over 65 years dwelling in a rural area, and they were divided into experimental and control groups each with 30 people. A social support program was implemented 6 hours a day, 3 times a week, for 4 months in the experimental group. Included was health assessment, health education, counseling, consultation, exercise, physical & occupational therapy, primary care, recreation, lunch & transfer service. Data was collected from May 1stto September 14th, 2002 by questionnaires, and analyzed by $x^2$-test, t-test, Pearson's correlation coefficient and stepwise multiple regression using SAS. Result: The social support program in the elderly was very effective on all dependent variables of physical health (t=4.68, p=.001), health knowledge (t=3.60, p=.001), life satisfaction (t=8.65, p=.001), and health promoting behaviors (t=5.23, p=.001). Conclusion: The Social Support Program at a Community Health Center was effective on health promoting behaviors in the elderly.

Introduction to Tasks in the International Cooperation Project, DECOVALEX-2023 for the Simulation of Coupled Thermohydro-mechanical-chemical Behavior in a Deep Geological Disposal of High-level Radioactive Waste (고준위방사성폐기물 처분장 내 열-수리-역학-화학적 복합거동 해석을 위한 국제공동연구 DECOVALEX-2023에서 수행 중인 연구 과제 소개)

  • Kim, Taehyun;Lee, Changsoo;Kim, Jung-Woo;Kang, Sinhang;Kwon, Saeha;Kim, Kwang-Il;Park, Jung-Wook;Park, Chan-Hee;Kim, Jin-Seop
    • Tunnel and Underground Space
    • /
    • v.31 no.3
    • /
    • pp.167-183
    • /
    • 2021
  • It is essential to understand the complex thermo-hydro-mechanical-chemical (THMC) coupled behavior in the engineered barrier system and natural barrier system to secure the high-level radioactive waste repository's long-term safety. The heat from the high-level radioactive waste induces thermal pressurization and vaporization of groundwater in the repository system. Groundwater inflow affects the saturation variation in the engineered barrier system, and the saturation change influences the heat transfer and multi-phase flow characteristics in the buffer. Due to the complexity of the coupled behavior, a numerical simulation is a valuable tool to predict and evaluate the THMC interaction effect on the disposal system and safety assessment. To enhance the knowledge of THMC coupled interaction and validate modeling techniques in geological systems. DECOVALEX, an international cooperation project, was initiated in 1992, and KAERI has participated in the projects since 2008 in Korea. In this study, we introduced the main contents of all tasks in the DECOVALEX-2023, the current DECOVALEX phase, to the rock mechanics and geotechnical researchers in Korea.

Factors Affecting International Transfer Pricing of Multinational Enterprises in Korea (외국인투자기업의 국제이전가격 결정에 영향을 미치는 환경 및 기업요인)

  • Jun, Tae-Young;Byun, Yong-Hwan
    • Korean small business review
    • /
    • v.31 no.2
    • /
    • pp.85-102
    • /
    • 2009
  • With the continued globalization of world markets, transfer pricing has become one of the dominant sources of controversy in international taxation. Transfer pricing is the process by which a multinational corporation calculates a price for goods and services that are transferred to affiliated entities. Consider a Korean electronic enterprise that buys supplies from its own subsidiary located in China. How much the Korean parent company pays its subsidiary will determine how much profit the Chinese unit reports in local taxes. If the parent company pays above normal market prices, it may appear to have a poor profit, even if the group as a whole shows a respectable profit margin. In this way, transfer prices impact the taxable income reported in each country in which the multinational enterprise operates. It's importance lies in that around 60% of international trade involves transactions between two related parts of multinationals, according to the OECD. Multinational enterprises (hereafter MEs) exert much effort into utilizing organizational advantages to make global investments. MEs wish to minimize their tax burden. So MEs spend a fortune on economists and accountants to justify transfer prices that suit their tax needs. On the contrary, local governments are not prepared to cope with MEs' powerful financial instruments. Tax authorities in each country wish to ensure that the tax base of any ME is divided fairly. Thus, both tax authorities and MEs have a vested interest in the way in which a transfer price is determined, and this is why MEs' international transfer prices are at the center of disputes concerned with taxation. Transfer pricing issues and practices are sometimes difficult to control for regulators because the tax administration does not have enough staffs with the knowledge and resources necessary to understand them. The authors examine transfer pricing practices to provide relevant resources useful in designing tax incentives and regulation schemes for policy makers. This study focuses on identifying the relevant business and environmental factors that could influence the international transfer pricing of MEs. In this perspective, we empirically investigate how the management perception of related variables influences their choice of international transfer pricing methods. We believe that this research is particularly useful in the design of tax policy. Because it can concentrate on a few selected factors in consideration of the limited budget of the tax administration with assistance of this research. Data is composed of questionnaire responses from foreign firms in Korea with investment balances exceeding one million dollars in the end of 2004. We mailed questionnaires to 861 managers in charge of the accounting departments of each company, resulting in 121 valid responses. Seventy six percent of the sample firms are classified as small and medium sized enterprises with assets below 100 billion Korean won. Reviewing transfer pricing methods, cost-based transfer pricing is most popular showing that 60 firms have adopted it. The market-based method is used by 31 firms, and 13 firms have reported the resale-pricing method. Regarding the nationalities of foreign investors, the Japanese and the Americans constitute most of the sample. Logistic regressions have been performed for statistical analysis. The dependent variable is binary in that whether the method of international transfer pricing is a market-based method or a cost-based method. This type of binary classification is founded on the belief that the market-based method is evaluated as the relatively objective way of pricing compared with the cost-based methods. Cost-based pricing is assumed to give mangers flexibility in transfer pricing decisions. Therefore, local regulatory agencies are thought to prefer market-based pricing over cost-based pricing. Independent variables are composed of eight factors such as corporate tax rate, tariffs, relations with local tax authorities, tax audit, equity ratios of local investors, volume of internal trade, sales volume, and product life cycle. The first four variables are included in the model because taxation lies in the center of transfer pricing disputes. So identifying the impact of these variables in Korean business environments is much needed. Equity ratio is included to represent the interest of local partners. Volume of internal trade was sometimes employed in previous research to check the pricing behavior of managers, so we have followed these footsteps in this paper. Product life cycle is used as a surrogate of competition in local markets. Control variables are firm size and nationality of foreign investors. Firm size is controlled using dummy variables in that whether or not the specific firm is small and medium sized. This is because some researchers report that big firms show different behaviors compared with small and medium sized firms in transfer pricing. The other control variable is also expressed in dummy variable showing if the entrepreneur is the American or not. That's because some prior studies conclude that the American management style is different in that they limit branch manger's freedom of decision. Reviewing the statistical results, we have found that managers prefer the cost-based method over the market-based method as the importance of corporate taxes and tariffs increase. This result means that managers need flexibility to lessen the tax burden when they feel taxes are important. They also prefer the cost-based method as the product life cycle matures, which means that they support subsidiaries in local market competition using cost-based transfer pricing. On the contrary, as the relationship with local tax authorities becomes more important, managers prefer the market-based method. That is because market-based pricing is a better way to maintain good relations with the tax officials. Other variables like tax audit, volume of internal transactions, sales volume, and local equity ratio have shown only insignificant influence. Additionally, we have replaced two tax variables(corporate taxes and tariffs) with the data showing top marginal tax rate and mean tariff rates of each country, and have performed another regression to find if we could get different results compared with the former one. As a consequence, we have found something different on the part of mean tariffs, that shows only an insignificant influence on the dependent variable. We guess that each company in the sample pays tariffs with a specific rate applied only for one's own company, which could be located far from mean tariff rates. Therefore we have concluded we need a more detailed data that shows the tariffs of each company if we want to check the role of this variable. Considering that the present paper has heavily relied on questionnaires, an effort to build a reliable data base is needed for enhancing the research reliability.