• Title/Summary/Keyword: comparative assessment

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A Basic Study for Wind Energy of Building Cladding using Computational Fluid Dynamics (CFD를 이용하여 건물 외피의 바람에너지에 관한 적용연구)

  • Chung, Yung-Bea
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.39.2-39.2
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    • 2011
  • The new and renewable energy today has a great interest in all countries around the world. In special it has need more limit of the fossil fuel that needs of low carbon emission among the social necessary conditions. Recently, the high-rise building demand the structural safety, the economic feasibility and the functional design. The high-rise building spends enormous energy and it satisfied the design in solving energy requirements. The requirements of energy for the building depends on the partly form wind energy due to the cladding of the building that came from the surroundings of the high-rise building. In this study of the wind energy, the cladding of the building was assessed a tentative study. The wind energy obtains from several small wind powers that came from the building or the surrounding of the building. In making a cladding the wind energy forms with wind pressure by means of energy transformation methods. The assessment for the building cladding was surrounded of wind speed and wind pressure that was carried out as a result of numerical simulation of wind environment and wind pressure which is coefficient around the high-rise building with the computational fluid dynamics. In case of the obtained wind energy from the pressure of the building cladding was estimated by the simulation of CFD of the building. The wind energy at this case was calculated by energy transform methods: the wind pressure coefficients were obtained from the simulated model for wind environment using CFD as follow. The concept for the factor of $E_f$ was suggested in this study. $$C_p=\frac{P_{surface}}{0.5{\rho}V^{2ref}}$$ $$E_c=C_p{\cdot}E_f$$ Where $C_p$ is wind pressure coefficient from CFD, $E_f$ means energy transformation parameter from the principle of the conservation of energy and $E_c$ means energy from the building cladding. The other wind energy that is $E_p$ was assessed by wind power on the building or building surroundings. In this case the small wind power system was carried out for wind energy on the place with the building and it was simulated by computational fluid dynamics. Therefore the total wind energy in the building was calculated as the follows. $$E=E_c+E_p$$ The energy transformation, which is $E_f$ will need more research and estimation for various wind situation of the building. It is necessary for the assessment to make a comparative study about the wind tunnel test or full scale test.

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Effects on Water Quality in the Development and the Comparative Analysis of Water Quality Results in Post-environmental Impact Investigation - Focused on a Quarry Mine and Sports Facilities - (개발 사업에 의한 수질영향조사 및 사후환경영향조사 수질결과에 대한 비교·분석 -토석채취사업 및 체육시설 조성사업을 중심으로-)

  • Lee, Seyong;Roh, Younghee;Cho, Hanna;Maeng, Junho
    • Journal of Environmental Impact Assessment
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    • v.26 no.6
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    • pp.524-537
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    • 2017
  • Post-Environmental impact investigation(Post-EII) plays an important role in investigating and reducing the environmental impacts of construction operations in South Korea. To date, it has been estimated that the results for Post-EII showed the low reliability; however, understanding those reliability has rarely been studied. We investigated the effect on water qualities by construction operations of the quarry mine, training center, and golf club in South Korea. In addition, the results of water quality analysis in this study were compared and analyzed with those in Post-EII. Treated wastewater in a quarry mine showed high concentrations of biochemical oxygen demand(BOD), suspended solid(SS), total nitrogen(T-N), and total phosphorus(T-P). Compared with the water quality results between this study and Post-EII, the concentrations of BOD, SS, T-N, and T-P in the treated wastewater were higher than the interquartile range(IQR) as well as the range of the results from minimum to maximum in Post-EII(p<0.05). The concentrations of BOD, SS, T-N, and T-P in treated wastewater were high under constructions in a training center. The concentrations of BOD and SS exceeded the consultation standard for the treated wastewater. These concentrations showed the significant difference with the IQR and the range from minimum to maximum of the water quality results in Post-EII(p<0.05). Therefore, the management and monitoring for water quality should be conducted in the treated wastewater by of construction operations. In addition, the alternative to enhance the reliability for the water quality results should be sought in Post-EII.

The Comparative Analysis of the Internal Control According to Economic Changes in Korean Companies

  • Park, Cheol-Soo
    • Journal of Information Technology Applications and Management
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    • v.21 no.3
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    • pp.119-133
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    • 2014
  • Prior to the 2000s, internal control had not been among the high priority issues in the management's agenda. Since then, however, it has become one of the hottest issues, and has received a significant attention as the means of improving the transparency, sustainability, and competitiveness of a company. The objectives of this paper are to examine if there has been any noticeable changes in the level of internal controls of Korean companies before and after the 2010, and to analyze the underlying drivers and issues thereto. Accounting manipulation and moral hazard were among the factors to cause the Korean financial crisis in 1997 and 2008. Since then, the capital market has had a strong pressure on Korean companies to enhance the transparency of management and accounting while the government has made the laws, requirements, and recommendations to alleviate the moral hazard problems of management and enhance the accounting transparency. Both market and government have driven companies to put more priority on the reliability of financial reporting and the compliance of applicable laws and regulations. Thereby, the market and governmental forces has led companies to enhance the level of internal controls which contribute to the reliability of financial reporting and the compliance The pressure on companies to enhance the level of internal controls may be different across industries. The capital market and government experiencing the severe financial crisis in 1997 and 2008 put even more pressure on financial companies such as banks to upgrade the reliability of financial reporting and the compliance of regulations to the global level than on non-financial companies. A survey is performed on the changes in the level of internal controls of 54 major companies consisting of 10 financial and 44 non-financial companies in Korea. The survey results show that the average level of internal controls of Korean companies has noticeably improved and that the change in the level of control environment factor is higher than that of IT control factor. The analysis on the industry differences shows that financial companies increased the level of control environment factor more than non-financial companies did while non-financial companies upgraded the level of IT control factor more than financial companies did relatively. Among internal control categories, the most improved area since the economic crisis is "Risk Assessment." The global best practices for risk management have been developed primarily in the financial industry and then spread to other industries. The general level of control practices of Korean companies has been improving significantly, but still appears below the global advanced practices.

Three-dimensional assessment of condylar surface changes and remodeling after orthognathic surgery

  • Lee, Jung-Hye;Lee, Woo-Jin;Shin, Jae-Myung;Huh, Kyung-Hoe;Yi, Won-Jin;Heo, Min-Suk;Lee, Sam-Sun;Choi, Soon-Chul
    • Imaging Science in Dentistry
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    • v.46 no.1
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    • pp.25-31
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    • 2016
  • Purpose: This study was performed to evaluate condylar surface changes and remodeling after orthognathic surgery using three-dimensional computed tomography (3D CT) imaging, including comparisons between the right and left sides and between the sexes. Materials and Methods: Forty patients (20 males and 20 females) who underwent multi-detector CT examinations before and after surgery were selected. Three-dimensional images comprising thousands of points on the condylar surface were obtained before and after surgery. For the quantitative assessment of condylar surface changes, point-to-point (preoperative-to-postoperative) distances were calculated using 3D processing software. These point-to-point distances were converted to a color map. In order to evaluate the types of condylar remodeling, the condylar head was divided into six areas (anteromedial, anteromiddle, anterolateral, posteromedial, posteromiddle, and posterolateral areas) and each area was classified into three types of condylar remodeling (bone formation, no change, and bone resorption) based on the color map. Additionally, comparative analyses were performed between the right and left sides and according to sex. Results: The mean of the average point-to-point distances on condylar surface was $0.11{\pm}0.03mm$. Bone resorption occurred more frequently than other types of condylar remodeling, especially in the lateral areas. However, bone formation in the anteromedial area was particularly prominent. No significant difference was found between the right and left condyles, but condylar surface changes in males were significantly larger than in females. Conclusion: This study revealed that condylar remodeling exhibited a tendency towards bone resorption, especially in the lateral areas. Condylar surface changes occurred, but were small.

A Study on Analyzing Precedents and Legal System of Landscape Tree Damage by Natural Disasters (자연재해로 인한 조경수목 피해 판례 및 제도분석 연구)

  • Yu, Joo-Eun;Lee, Sang-Suk
    • Journal of the Korean Institute of Landscape Architecture
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    • v.41 no.4
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    • pp.77-84
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    • 2013
  • With the increase in occurrence frequency and severity of natural disasters due to climate changes arising from global warming, damage in the landscaping field is rising. This leads to legal disputes, and is increasing social and economic damage, too. Especially even though landscape trees which are highly affected by external environments, suffer lots of damage from natural disasters, there is no specific scope of disaster criteria and thus it brings plenty of problems of damage restoration and compensation. Therefore, this study aims to suggest that gives ways to improve related criteria for damage of landscape trees from natural disasters. For this objective, this study analyzed damage cases of landscape trees and precedents, and compared Korean and Japanese legal systems and criteria regarding natural disasters with each other. The analysis result showed that opinions of experts have a great deal of influence on judgment results, since there is no definite legal basis on damage from natural disasters in the landscaping field. This implies the need for a professional and objective appraisal process. According to the comparative analysis of Korean and Japanese legal systems and criteria regarding natural disasters, Korea lacked in laws and criteria on natural disasters of landscape plants in Korea, whereas there were concrete disaster assessment standards of landscape trees in Japan. For improving natural disaster-related systems and criteria in the landscaping field, therefore, this study presented 'Revision of related laws', 'Revision of appraisal and loss assessment criteria', 'Revision of standard specification of landscaping project', 'Compulsory insuring against disasters', 'Reasonable fulfillment of contract', and 'Compulsory cost estimation for disaster restoration', as improvement plans.

A Comparative Study of Mathematics Curriculum among the United States, Singapore, England, Japan, Australia and Korea (수학 교육과정 국제 비교 분석 연구 - 미국, 싱가포르, 영국, 일본, 호주의 중학교와 고등학교 교육과정을 중심으로 -)

  • Chong, Yeong Ok;Chang, Kyung-Yoon;Kim, Gooyeon;Kwon, Na Young;Kim, Jin Ho;Seo, Dong-Yeop;Kang, Hyun-Young;Park, Sunhwa;Ko, Ho Kyoung;Nam, Jin Young;Tak, Byungjoo
    • Journal of Educational Research in Mathematics
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    • v.26 no.3
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    • pp.371-402
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    • 2016
  • The aim of this study is to compare mathematics curriculum among the United States, Singapore, England, Japan, Australia and Korea and offer suggestions to improve mathematics curriculum of Korea in the future. In order to attain these purposes, the analysis was conducted in many aspects including mathematics education system, mathematics courses, mathematics contents, assessment syllabus for university entrance examination and the construction principles of mathematics curriculum. In the light of the results of this study, our suggestions for improving mathematics curriculum of Korea are as follows: revising the contents of analysis, geometry, probability and statistics strands; organizing curriculum based on spiral construction principle; providing various opportunities to select mathematics courses according to students'career; reflecting the contents of their courses in university entrance examination.

Comparison of Active and Passive Sampler for Determining Temperal and Spatial Concentration Assessment of the Main Volatile Organic Compounds Concentration in Shihwa Industrial Complex (시화산업단지에서 주요 휘발성유기물질의 시간적, 공간적 농도 파악을 위한 능동식과 수동식 시료채취기 비교)

  • Byeon, Sang-Hoon;Choi, Hyeon-Il;Moon, Hyung-Il;Lee, Jung-Geun;Kim, Jung-Keun
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.11
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    • pp.790-796
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    • 2011
  • In this study, we measured the concentrations of volatile organic compounds (VOCs) in Shiwha area by using active and passive sampler. We did a comparative analysis of the characteristics of the active sampler and passive sampler. In the case of the passive sampler, the average TVOC concentration of the industrial area was 1.86 times higher than that of the residential area. In the case of the active sampler, the average TVOC concentration of the industrial area was 1.07 times higher than that of the residential area. When using the passive sampler, the concentration of VOCs in the industrial area was noted to be higher than the concentration found in the residential area. However, when we used the thermal desorption tube, the concentration of residential area was higher rather than that of industrial area in some substances such as trichloroethylene, toluene, ethylbenzene, and xylene. Toluene was a larger percentage of the overall BTEX ratio. In case of the passive sampler, the relative ratio of toluene, ethylbenzene, and xylene was higher in the industrial area than in the residential area. In contrast in case of the thermal desorption tube, the ratio of these substances was higher in the residential area rather than in the industrial area. The passive sampling in this study showed an appropriate method to analyze the temporal and spatial concentrations of air contaminants. This assessment would prove to be useful for its observance of standards or epidemical study.

Development and Assessment of Harmful Gases Reducing Molded Fuel Using Torrefied Wood (반탄화목재를 이용한 유해가스 저감형 성형연료의 개발 및 평가)

  • LEE, Chang-Goo;EOM, Chang-Deuk;KIM, Min-Ji;KANG, Seog-Goo
    • Journal of the Korean Wood Science and Technology
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    • v.48 no.5
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    • pp.732-744
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    • 2020
  • In this study, a torrefaction of Quercus serrata to manufacture a molded charcoal was performed, investigated material properties, fuel characteristics, and performed a quantitative analysis of hazardous gases which occur during a combustion process. In addition, a molded charcoal in market was selected as a control group, and a comparative analysis was performed. As a result, the higher heating value (HHV) of the torrefied specimen was about 14% higher than that of molded charcoal, and its ash content was about 51 times lower. Moreover, after performing a quantitative assessment of hazardous gases (carbon monoxide, nitrogen oxide, and sulfur dioxide) which were produced when each specimen was combusted for 900 seconds in an enclosed chamber, it was confirmed that the maximum value of generated amount of carbon monoxide on the torrefied specimen was about 50 times lower than that of the existing molded charcoal. Therefore, it was shown that the torrefied specimen produced in this study had a higher heating value than the molded charcoal in the market, and a very low amount of carbon monoxide generated during the combustion process.

A Comparative study among 2nd cycle of Evaluation and Accreditation system on Korean Medicine Education, Global Standards of WFME for Basic Medical Education and WHO guidelines for quality assurance of Traditional Medicine Education in the Western Pacific Region (한의학교육평가원 2주기, 세계의학교육연합회(WFME)의 의학기본교육, WHO 서태평양 지역지부(WHO/WPRO) 인증 기준 간의 비교 연구)

  • Sun, Seung Ho
    • Journal of Society of Preventive Korean Medicine
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    • v.23 no.3
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    • pp.41-57
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    • 2019
  • Objective : The purpose of our study is to compare and analyze the standards for the 2nd cycle of Evaluation and Accreditation system on institute of Korean Medicine Education & Evaluation (2nd IKMEE standards) and WHO guidelines for quality assurance of Traditional Medicine Education in the Western Pacific Region (WHO/WPRO guidelines) around the global standards of World Federation for Medical Education for basic medical education (WFME standard) to identify the shortcomings and improvements of 2nd IKMEE standards. Method : Each article of 2015 revised WFME standard was translated and summarized with focus on its core content. The next step was to review and analyze the corresponding contents of 2nd IKMEE standards in 2016 and the WHO/WPRO guidelines in 2005 for each item, focusing on the WFME standards. Results : All items in the fields of 3. assessment of students and 7. program evaluation in the WFME domain were absent from the 2nd IKMEE standards, and almost none of the WHO/WPRO guidelines. Most items in 1. the mission and outcomes domain, except for some items in the 1.1 mission field, the items of 2.6~2.8 fields in 2. education program domain, the items of 4. student domain except for the items of 4.3 student counseling and support field, and almost all items about quality development in WFME standards did not have a corresponding item in both the 2nd IKMEE standards and the WHO/WPRO standards. Conclusion : 1. The WFME standards are applicable to the criteria development of IKMEE standards. Several items of the WFME standards may need to be modified to apply the educational characteristics of Korean medicine, but consensus or further study is required. 2. Both the 2nd IKMEE standards and the WHO/WPRO standards are very insufficient to meet the WFME standards. In particular, 3. assessment of students and 7. program evaluation in the WFME domain were not in the 2nd IKMEE standards. This standard needs to be supplemented.

A Comparative Study on Dietary Life according to the Obesity Assessment Methods of Higher Grade Elementary School Students in Jeonju (전주지역 고학년 초등학생의 비만판정 방법에 따른 식생활 비교연구)

  • Yu, Ok-Kyeong;Cha, Youn-Soo
    • Korean Journal of Human Ecology
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    • v.9 no.4
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    • pp.83-93
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    • 2006
  • This study was done for finding out if eating habits, eating behaviors were different between non-obese and obese elementary school students in Jeonju Area. Total 2568 students of 1364 male and 1204 female of the 4th, 5th, and 6th year in 5 elementary schools were surveyed and the statistics of the result was analyzed by SPSS program. The results are summarized as follows: 1. Obesity was defined as Body Mass Index(BMI) that exceeded 85th and Obesity Index(OI) that exceeded 110. First, subjects were divided into 4 groups : lean, normal, overweight and obese. Second subjects were reclassified into non-obese(lean and normal) and obese(overweight and obese) groups. Average height of male and female students were 142.5cm, 143.1cm and weight of those were 36.4kg and 37.9kg respectively. 2. As results of obesity computation, obese male students were 19.6%(overweight 11.3%, obese 8.3%) in BMI and obese male students were 25.0%(overweight 12.5.%, obese 12.5%) in OI. Especially Obesity percent rate of male student were significantly higher on that of female student in OI method. 3. Examining obesity between male and female, there were statistically different between male students and female students in OI, but there were not statistically different in BMI. With regard to grade level(4th, 5th, 6th), there were statistically different among grade levels. 4. Examining correlation between eating habits(eating behaviors) and obesity, there were statistically significant in some cases. For example, there were statistically significant correlation between fast eating habit and obesity. And the relation analysis of general environments and obesity showed that there were statistically significant in some cases. These results suggest that the number of overweight students can be increased due to the amount and kinds of food children have as well as the general causes of overweight such as genetic, environmental and psychological reason. Surveying about children's eating habits, eating behaviors this study methodically. Working with parents is necessary and comparison of eating habits, eating behaviors and nutrition knowledge between the past and their presents are also needed in a future.

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