• Title/Summary/Keyword: IMPACT2002+

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FRACTURE TOUGHNESS CHARACTERISTICS IN HIGH ENERGY DENSITY BEAM WELDED JOINT OF HIGH TENSILE STEELS

  • Ro, Chan-Seung;Yamada, Tomoaki;Mochizuki, Masahito;Ishikawa, Nobuyuki;Bang, Han-Sur;Toyoda, Masao
    • Proceedings of the KWS Conference
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    • 2002.10a
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    • pp.583-588
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    • 2002
  • The purpose of the study is to evaluate fracture toughness on the Laser and the electron beam welded joints of high tensile steels (HT500, HT550, HT650) by using 3-point bend CTOD and Charpy impact test. WM (weld metal) CTOD tests have been carried out using two kinds of CTOD specimen, the Laser beam welding (108mm length, and 24mm width, and 12mm thickness) and the electron beam welding (l71mm length, and 38mm width, and 19mm thickness). WM Charpy impact specimen is a standard V-notch type, and the temperature of the experiment is changed from -45 to 20 degree of centigrade. FE-analysis is also performed in order to investigate the effect of stress-strain fields on fracture characteristics. Results of the standard V-notch Charpy test are influenced by strength mis-match effect and the absorbed energy vE depends on crack path, and The transition temperature of Laser beam welded joints is more higher than that of electron beam welded joints. Results of the 3-point bend test give low critical CTOD and the crack path is in the weld metal of al specimens. These results indicate fracture toughness characteristics of the welded joints and transition temperature of HT500 are similar both a Laser beam welded joint and an electron beam welded joint. But the fracture toughness and the transition temperature of the electron beam welded joints of HT550 and HT650 are higher than those o the Laser beam welded joints.

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Risk Perception and Need to Regulate towards Environmental Problems in Korea (우리나라 환경문제의 인지 위해도와 정부규제의 필요성에 관한 연구)

  • Lim, Young-Wook;Shin, Dong-Chun;Hwang, Man-Sik;Park, Chong-Yon;Kim, Hwang-Ryong
    • Journal of Environmental Impact Assessment
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    • v.11 no.3
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    • pp.145-155
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    • 2002
  • A substantial literatures on environmental risk perception have emerged since the late 1960s. Most these works focus on how people form risk perception, on what people believe, on difficulties in communicating information about health, safety, or environmental risks to non-experts. In this study, questionnaire surveys were conducted to sample from stakeholders(general public, environmental specialist, governmental official, non-government officials, journalist) during March and Aprils, 2000. Total number of responses was 1,803 including 773 persons of general public, 353 experts, 390 governmental officials, 111 journalists and 176 NGO members. Risk perception on 26 environmental issues were statistically analyzed to relate with the need to regulate each issues, interest and knowledge, experience of hazard, satisfaction in environmental situation, etc. This research aims to aid risk analysis and policy-making by providing a basis for understanding and anticipating group responses to environmental issues and improving the communication of risk information among general public, lay-people, technical experts, and decision-makers. This study concludes that those who are in charge of promoting and regulating health and safety of citizens should understand how people perceive about and respond to environmental risk. Without such understanding, well-intended environmental policies of governments would be ineffective.

Trends in daily precipitation events and their extremes in the southern region of Korea (남부지방의 강수강도와 극값의 변화경향에 관한 연구)

  • Choi, Young-Eun
    • Journal of Environmental Impact Assessment
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    • v.11 no.3
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    • pp.189-203
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    • 2002
  • 호우는 우리나라에 매년 약 60여명의 인명과 6,000억원에 달하는 재산 손실을 가져오는 가장 파괴적인 자연 재해이다. 그러므로, 강수 행태의 변화, 특히 호우 빈도와 규모의 변화를 이해하는 것은 악기상과 관련된 재해를 최소화하는데 필요한 환경영향평가에 필수적이다. 최근 기후변화의 징후로써 뿐만 아니라 사회에 미치는 영향 때문에 강수 극값에 대한 관심이 크게 증가하고 있다. 기후변화가 사회에 영향을 미치게 될 규모는 기후변동성의 변화, 특히 기후극값의 강도와 빈도에 의해서 결정 될 것이다. 본 연구의 목적은 한반도 남부지방의 장기간의 강수강도와 극값의 변화 경향을 파악하는 것이다. 장기간의 일 강수 자료(1920-1999)를 보유하고 있는 대구, 전주, 부산, 목포의 자료를 산술 평균하여 남부지방의 지역 일 강수 계열을 구축하였다. 남부지방의 연강수일수는 뚜렷한 감소현상이 나타나는 반면 연강수량은 약한 증가현상을 보인다. 이로 인해서 강수일수당 강수량을 보여주는 강수강도는 뚜렷하게 증가하고 있다. 이 모든 경향은 통계적으로 유의한 수준의 변화이다. 계절별로는 여름의 강수량 증가와 가을의 강수일 수 감소가 가장 뚜렷하다. 또한 강수극값의 규모를 나타내는 90번째, 95번째, 99번째 백분위수의 값도 증가하는 경향을 보여주고 있다. 호우 사상의 발생빈도와 그에 의한 강수량은 증가하는 반면, 비호우 사상의 발생빈도는 감소하고, 그에 의한 강수량에는 뚜렷한 경향이 나타나지 않았다. 남부지방에 나타난 강수일수의 감소는 비호우 사상의 감소에 의한 것이었고, 강수량의 증가는 호우 사상의 발생빈도와 그에 의한 강수량 증가에 의한 것 임을 알 수 있다. 위의 결과는 한반도에서도 기후변화에 의한 수문순환의 강화를 나타나고 있음을 보여주는 것으로, 기후변화에 대응하기 위한 적절한 지역영향평가를 위해서는 강수 극값에 대한 보다 상세한 분석이 필요함을 제안하고 있다.

Traffic Accident Prediction Model by Freeway Geometric Types (고속도로 선형조건별 교통사고 위험도 평가모형 개발 (호남고속도로를 중심으로))

  • 강정규;이성관
    • Journal of Korean Society of Transportation
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    • v.20 no.4
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    • pp.163-175
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    • 2002
  • Fatalities from traffic accidents constitute one of the major health issues as well as safety ones in Korea. It has been reported that traffic accident is affected by the combined effects of road. vehicle. and human factors. Over the past few decades, a number of studies have been conducted to find the impact of road geometric factors on traffic safety. The purpose of this study is to investigate the effect of road geometric factors on traffic safety on Korean expressways. Detailed geometric design data were available from Korea Highway Corporation. Five-year traffic accident data on Honam expressway were collected and analyzed. It was found that following geometric factors influence traffic safety on expressways : radius of curve, curve length, and length of straight section. Furthermore, the existence of I.C. turned out to have a significant impact on traffic safety level. Based on the data analysis several multiple regression forms that relate traffic accident frequencies and geometric factors on expressways are developed.

A Study on the Dynamic Wheel Loads of 3-D Vehicle Model Considering Tire Enveloping (타이어 접지폭을 고려한 3차원 차량모델에 의한 동적 차륜하중에 관한 연구)

  • Chung, Tae Ju
    • Journal of Korean Society of Steel Construction
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    • v.14 no.1
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    • pp.95-104
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    • 2002
  • In this paper, research for dynamic wheel loads of 3-D vehicle model considering tire enveloping model is carried out. Heavy trucks with 2-axles and 3-axles are modeled by 7-d.o.f. and 8-d.o.f., in which contact length of tire and pitching of tandem spring axles is considered. Dynamic equations of vehicle are derived by using the Lagrange's equation and solution of the equation is calculated by 5th Runge-Kutter method. The validity of the developed 3-D vehicle model is demonstrated by comparing the results obtained by the present method and experimental data by Whittemore. The maximum impact factors of tire force are calculated when vehicle models of 8ton and 15ton dump truck are running on the different class roads with 1.0km and on the various step bump.

The Impact of Sales Revenue on Value Relevance in the Distribution Corporate (유통기업 매출액의 기업가치 관련성)

  • Kim, Jin-Hoe
    • Journal of Distribution Science
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    • v.16 no.2
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    • pp.83-88
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    • 2018
  • Purpose - For distribution corporate, the method of recognizing sales revenue may be different depending on the type of distribution transaction. Until the change in accounting standards for revenue recognition was made in 2002, the distribution corporate recognized the full amount of sales of goods regardless of the type of transaction. However, in accordance with accounting standards for revenue recognition, which began to be applied in 2003, distribution corporate differ in sales revenue recognition by transaction type. The Purpose of this study is to analyze the impact of sales revenue on the corporate value after the change of the revenue recognition accounting standards. Research design, data, and methodology - We selected a comprehensive wholesale and retail corporate listed on Korea Exchange. The research model extends the Ohlson(1995) model and regresses whether sales revenue affecting the corporate value is discriminatory value relevance between the corporate affected by changes in accounting standards for revenue recognition and those not. Results - The results of the analysis are as follows. First, The average value of stock price, net asset per share, and earnings per share are all higher than those before the change of accounting standards for revenue recognition. However, the average value of sales per share is lower than that before the change of accounting standards for revenue recognition. Second, the relationship between corporate value and net asset per share, earnings per share and sales per share, the coefficient of net asset per share, earnings per share and sales per share are all statistically significant positive value. Therefore, in explaining corporate value, besides net asset per share and earnings per share, sales per share provides additional information. And the coefficient of interaction variable between accounting standard change and sales per share is a statistically significant positive value. This result indicating that after the change of the revenue recognition accounting standards the usefulness of sales revenue has increased. Conclusions - The change in accounting standards for revenue recognition led to a decrease in distribution corporate sales revenue but the higher the relevance of the corporate value of the sales revenue information. These results shows that the change of accounting standards that reflects the transaction type of retailers was a revision to increase the value relevance of sales revenue in valuation of corporate value.

Numerical Simulations of the local circulation in coastal area using Four-Dimensional Data Assimilation Technique (4차원 자료동화 기법을 이용한 해안가 대기 순환의 수치 실험)

  • Kim, Cheol-Hee;Song, Chang-Keun
    • Journal of Environmental Impact Assessment
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    • v.11 no.2
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    • pp.79-91
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    • 2002
  • Four dimensional data assimilation (FDDA) technique was considered for 3 dimensional wind field in coastal area and a set of 3 numerical experiments including control experiments has been tested for the case of the synoptic weather pattern of the weak northerly geostrophic wind with the cloud amount of less than 5/10 in autumn. A three dimensional land and sea breeze model with the sea surface temperature (SST) of 290K was performed without nudging the observed wind field and surface temperature of AWS (Automatic Weather System) for the control experiment. The results of the control experiment showed that the horizontal temperature gradient across the coastline was weakly simulated so that the strength of the sea breeze in the model was much weaker than that of observed one. The experiment with only observed horizontal wind field showed that both the pattern of local change of wind direction and the times of starting and ending of the land-sea breeze were fairly well simulated. However, the horizontal wind speed and vertical motion in the convergence zone were weakly simulated. The experiment with nudgings of both the surface temperature and wind speed showed that both the pattern of local change of wind direction and the times of starting and ending of the land-sea breeze were fairly well simulated even though the ending time of the sea breeze was delayed due to oversimulated temperature gradient along the shoreline.

Charging Korean Off-Shore Fisheries for Sustainable Fishing (지속적 어업을 위한 적정 자원이용료 부과에 관한 연구)

  • 박성쾌;김기수;김은채
    • The Journal of Fisheries Business Administration
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    • v.33 no.2
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    • pp.49-74
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    • 2002
  • This study examines, from an economic perspective, the reasons for introducing a resource taxe system into the Korean off-shore fisheries and the type of charges that can be introduced. Following a review of the charging systems in other advanced fisheries, we consider the types of charging scheme and some implications for the Korean off-shore fishing industry. Charges could be used for recovering part of fisheries management cost from the industry(i.e. administration, enforcement, research, etc). This can be justified on the grounds that the fishing industry is the main beneficiary of management and that it should therefore bear at least part of the cost involved. It is arguable that publicly-funded management is in effect a subsidy to the industry. Using charges to raise revenue in excess of the cost of management would represent the extraction of a public rent from the fishery resource, but the short-run financial consqquences for the industry would be significant. Results from a qualtitative analysis suggest that while any new charge will have a significant financial impact on the industry in the short run, a landings tax would have a lesser impact on fleet structure in the long run. The study also considers the possibility of a capital gains tax on license sales in order to recover some rent from the industry. Despite any short run-financial consequences, making the fishing industry pay for at least some of the cost of management could benefit the industry as a whole if there were more cooperation between industry and managers as a result. It is acknowledged, however, that there could be disputes over the relative management costs of different sectors of the industry. Even though this study makes few specific recommendations about charging the Korean off-shore fishing industry, it does advise that the issue be reviewed on the basis of the entire Korea fisheries. Finally, the study notes that insufficient data are available on the economic performance of the Korean off-shore fishing vessels and it recommands that a comprehensive system for the collection of costs and earnings data be put in place. It also suggests that MOMAF pay much attention to the permit right market and its transactions.

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The Impact of TANF on Income and Poverty : analyses by sub-component (미국 TANF정책이 소득 및 빈곤에 미친 영향: 하부조항별 분석)

  • Yoo, Ji-Young
    • Korean Journal of Social Welfare
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    • v.59 no.4
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    • pp.111-136
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    • 2007
  • The National Basic Livelihood Security(NBLS) System implemented from October 2000 has expanded cash assistance to cover the poor who are able to work in our country. Although the cash assistance for them has positive aspects of providing basic livelihood security for all people, but many scholars have also pointed out its negative aspects such as a decrease in labor supply among the poor. In order to provide policy implications for the cash assistance program of our country as well as the US, this paper examines the impact of Temporary Assistance for Needy Families(TANF) on poverty among single mothers and their families using data from March Current Population Survey of $1991{\sim}2002$. TANF imposes strong work requirements and time limits to recipients as conditions for cash assistance, which are major sub-components of TANF. Therefore, this paper analyzes TANF by looking at work requirements and time limits separately, not by looking at TANF as a single policy. The research findings show that work requirements significantly decreased income and increased poverty among single mothers. Although time limits show income increasing effects and poverty decreasing effects, it seems further studies on time limits are needed at this point. The research findings of this paper provide important lessons for welfare to work cash assistance of our country as well as the US.

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Professional Socialization of Oriental Medical Students (한의대생의 전문직 사회화과정 연구)

  • Kim Chang-Yup;Kim Kwang-Ho;Lim Byung-Mook
    • Journal of Society of Preventive Korean Medicine
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    • v.6 no.2
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    • pp.48-63
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    • 2002
  • The study aims to investigate the process of professional socialization of oriental medical students, to analyze influencing factors on it, and to compare the results with those of western medical students. Professional socialization, in the context of this study, means the process through which a layperson becomes a profession equipped with professional identity and values. A survey using specially designed questionnaire was carried out in 1999. The data were collected from 11 oriental medical colleges for 2,656 students. A total of 2,597 cases was finally included in the statistical analysis. Analysis of factors related to professional value found that oriental medical students thought highly of human-oriented factors, followed by science and status, and this trend remained unchanged as they moved on to qualification. Among professionalism related items, those involved in professional regulation and dominance factors showed high scores, while showing low scores on items related to bio-ethics and autonomy factors. Unlike items of professional value, those of professionalism showed a notable difference in attitude statistically by schooling level. The average scores of factors for professionalism increased with increasing schooling years. This trend proved that oriental medical students acquired professional norms and attitudes through their educational period. Multiple regression analysis with the factors related to professional value and professionalism as dependent variables found that independent variables had some impact on science, status, and clinical autonomy, but no impact on human, policy autonomy, and professional regulation factors. In conclusion, with increasing schooling years, professional norms and attitudes of oriental medical students were also strengthened. And, in spite of the differences in general propensity, they have a base consciousness in common with western medical students. The difference of mind-set and attitudes related to professionalism in the two groups, however, considering the necessity of future cooperative relations, indicated that a common curriculum between both schools is needed, and the education of social medicine should be strengthened in oriental medical colleges.

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