• Title/Summary/Keyword: 공정개선

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A Study on the Replacement of a Light Burnt Dolomite with a Waste MgO-C Refractory Material for a Steel-Making Flux in Electric Arc Furnace (폐 MgO-C계 내화재의 전기로(EAF) 제강 Flux용 경소돌로마이트 대체 사용 연구)

  • Hyun-Jong Kim;Jong-Deok Lim;Hang-Goo Kim;Jei-Pil Wang
    • Resources Recycling
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    • v.31 no.6
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    • pp.44-51
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    • 2022
  • In the steelmaking process using an electric arc furnace (EAF), light-burnt dolomite, which is a flux containing MgO, is used to protect refractory materials and improve desulfurization ability. Furthermore, a recarburizing agent is added to reduce energy consumption via slag foaming and to induce the deoxidation effect. Herein, a waste MgO-C based refractory material was used to achieve the aforementioned effects economically. The waste MgO-C refractory materials contain a significant amount of MgO and graphite components; however, most of these materials are currently discarded instead of being recycled. The mass recycling of waste MgO-C refractory materials would be achievable if their applicability as a flux for steelmaking is proven. Therefore, experiments were performed using a target composition range similar to the commercial EAF slag composition. A pre-melted base slag was prepared by mixing SiO2, Al2O3, and FeO in an alumina crucible and heating at 1450℃ for 1 h or more. Subsequently, a mixed flux #2 (a mixture of light-burnt dolomite, waste MgO-C based refractory material, and limestone) was added to the prepared pre-melted base slag and a melting reaction test was performed. Injecting the pre-melted base slag with the flux facilitates the formation of the target EAF slag. These results were compared with that of mixed flux #1 (a mixture of light-burnt dolomite and limestone), which is a conventional steelmaking flux, and the possibility of replacement was evaluated. To obtain a reliable evaluation, characterization techniques like X-ray diffraction (XRD) analysis and X-ray fluorescence (XRF) spectrometry were used, and slag foam height, slag basicity, and Fe recovery were calculated.

A Study on the Revitalization of the Competency Assessment System in the Public Sector : Compare with Private Sector Operations (공공부문 역량평가제도의 활성화 방안에 대한 연구 : 민간부분의 운영방식과의 비교 연구)

  • Kwon, Yong-man;Jeong, Jang-ho
    • Journal of Venture Innovation
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    • v.4 no.1
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    • pp.51-65
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    • 2021
  • The HR policy in the public sector was closed and operated mainly on written tests, but in 2006, a new evaluation, promotion and education system based on competence was introduced in the promotion and selection system of civil servants. In particular, the seniority-oriented promotion system was evaluated based on competence by operating an Assessment Center related to promotion. Competency evaluation is known to be the most reliable and valid evaluation method among the evaluation methods used to date and is also known to have high predictive feasibility for performance. In 2001, 19 government standard competency models were designed. In 2006, the competency assessment was implemented with the implementation of the high-ranking civil service team system. In the public sector, the purpose of the competency evaluation is mainly to select third-grade civil servants, assign fourth-grade civil servants, and promotion fifth-grade civil servants. However, competency assessments in the public sector differ in terms of competency assessment objectives, assessment processes and competency assessment programmes compared to those in the private sector. For the purposes of competency assessment, the public sector is for the promotion of candidates, and the private sector focuses on career development and fostering. Therefore, it is not continuously developing capabilities than the private sector and is not used to enhance performance in performing its duties. In relation to evaluation items, the public sector generally operates a system that passes capacity assessment at 2.5 out of 5 for 6 competencies, lacks feedback on what competencies are lacking, and the private sector uses each individual's competency score. Regarding the selection and operation of evaluators, the public sector focuses on fairness in evaluation, and the private sector focuses on usability, which is inconsistent with the aspect of developing capabilities and utilizing human resources in the right place. Therefore, the public sector should also improve measures to identify outstanding people and motivate them through capacity evaluation and change the operation of the capacity evaluation system so that they can grow into better managers through accurate reports and individual feedback

Development of a Simultaneous Analytical Method for Azocyclotin, Cyhexatin, and Fenbutatin Oxide Detection in Livestock Products using the LC-MS/MS (LC-MS/MS를 이용한 축산물 중 유기주석계 농약 Azocyclotin, Cyhexatin 및 Fenbutatin oxide의 동시시험법 개발)

  • Nam Young Kim;Eun-Ji Park;So-Ra Park;Jung Mi Lee;Yong Hyun Jung;Hae Jung Yoon
    • Journal of Food Hygiene and Safety
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    • v.38 no.5
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    • pp.361-372
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    • 2023
  • Organotin pesticide is used as an acaricide in agriculture and may contaminate livestock products. This study aims to develop a rapid and straightforward analytical method for detecting organotin pesticides, specifically azocyclotin, cyhexatin, and fenbutatin oxide, in various livestock products, including beef, pork, chicken, egg, and milk, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The extraction process involved the use of 1% acetic acid in a mixture of acetonitrile and ethyl acetate (1:1). This was followed by the addition of anhydrous magnesium sulfate (MgSO4) and anhydrous sodium chloride. The extracts were subsequently purified using octadecyl (C18) and primary secondary amine (PSA), after which the supernatant was evaporated. Organotin pesticide recovery ranged from 75.7 to 115.3%, with a coefficient of variation (CV) below 25.3%. The results meet the criteria range of the Codex guidelines (CODEX CAC/GL 40). The analytical method in this study will be invaluable for the analysis of organotin pesticides in livestock products.

Influence of low-pressure tumbling on the quality characteristics of thawed pork (감압 텀블링 해동이 돈육의 품질 특성에 미치는 영향)

  • Won-Ho Hong;Jeong Kim;Yu-Jeong Gwak;Jiyeon Chun
    • Food Science and Preservation
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    • v.30 no.1
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    • pp.88-97
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    • 2023
  • As livestock consumption in Korea has been gradually increasing, the quality of the final products has been improved to meet this increased demand. In particular, maintaining the water holding capacity (WHC) and minimizing the drip loss during the thawing of frozen meat are of utmost importance. This study investigated the physicochemical properties of frozen pork subjected to thawing under different conditions: at room temperature (20℃, under air), at a low temperature (4℃ refrigerator, under air), under water (20℃, under water in a vacuum bag), under microwave (microwave-thawing, 260 W), and under low-pressure tumbling (20℃, 0.015 bar, tumbling). The shortest thawing time for frozen pork was recorded upon low-pressure tumbling thus indicating a fast heat transfer. The lowest drip loss (0.2%) and highest WHC (94.5%) were also recorded under this condition. A significantly higher drip loss was observed upon microwave- (1.0%) and water-thawing (1.2%), which resulted in the lowest WHC in microwave thawing (87.2%). The highest total count of aerobic bacteria and coliform group were observed upon room temp thawing while the low pressure tumbling and thawing resulted in the lowest aerobic bacteria (1.90 log CFU/g) and coliform (0.78 log CFU/g) count. Consequently, thawing by low pressure tumbling afforded the best food quality.

Physicochemical and textural properties of thawed pork by vacuum tumbling (진공 텀블링을 이용한 해동 돈육의 이화학적 및 조직학적 특성)

  • Su-Jin Park;Won-Ho Hong;Seung-Min Oh;Chang-Hee Cho;Jiyeon Chun
    • Food Science and Preservation
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    • v.31 no.3
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    • pp.423-432
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    • 2024
  • In this study, a vacuum tumbler with 4 impellers (DVT) was designed and applied for thawing frozen pork (vacuum -60 kPa, jacket 35℃, 1 rpm). Quality characteristics of the thawed pork were compared with those of industrially thawed meat by natural air at room temperature (NAT) and imported vacuum tumbler (IVT). The thawing time for frozen pork (303.36 kg) using DVT (165 min) was much shorter than that of NAT (4,200 min). DVT-thawed pork had lower drip loss (0.85%) than NAT (2.08%). DVT-thawed pork showed a pH of 5.92, a total bacterial count of 1.96±0.02 log CFU/g and no coliforms. Deteriorations in fat (TBARS 0.31±0.01 MDA mg/kg) and protein (VBN 5.67±1.98 mg%) in DVT-thawed pork were significantly lower than those of NAT (p<0.05). DVT-thawed pork had a high water-holding capacity (WHC, 97.5%). The hardness (34.59±0.46 N) and chewiness (188.21±0.17) of cooked DVT-thawed pork were about 5-6 times lower than those of NTA. Microstructure (SEM) showed myofibrillar damage in NAT-thawed pork, whereas dense myofibrillar structure was observed in DVT-thawed pork. DVT was better or similar to IVT in all evaluation parameters. The designed DVT is expected to be used as an efficient thawing method in terms of processing time and yield and to produce thawed meat with high WHC, soft texture, and low spoilage by minimizing tissue damage.

Environmental Pollution in Korea and Its Control (우리나라의 환경오염 현황과 그 대책)

  • 윤명조
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1972.03a
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    • pp.5-6
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    • 1972
  • Noise and air pollution, which accompany the development of industry and the increase of population, contribute to the deterioration of urban environment. The air pollution level of Seoul has gradually increased and the city residents are suffering from a high pollution of noise. If no measures were taken against pollution, the amount of emission of pollutant into air would be 36.7 thousand tons per year per square kilometer in 1975, three times more than that of 1970, and it would be the same level as that of United States in 1968. The main sources of air pollution in Seoul are the exhaust has from vehicles and the combustion of bunker-C oil for heating purpose. Thus, it is urgent that an exhaust gas cleaner should be instaled to every car and the fuel substituted by less sulfur-contained-oil to prevent the pollution. Transportation noise (vehicular noise and train noise) is the main component of urban noise problem. The average noise level in downtown area is about 75㏈ with maximum of 85㏈ and the vehicular homing was checked 100㏈ up and down. Therefore, the reduction of the number of bus-stop the strict regulation of homing in downtown area and a better maintenance of car should be an effective measures against noise pollution in urban areas. Within the distance of 200 metres from railroad, the train noise exceeds the limit specified by the pollution control law in Korea. Especially, the level of noise and steam-whistle of train as measured by the ISO evaluation can adversely affect the community activities of residents. To prevent environmental destruction, many developed countries have taken more positive action against worsening pollution and such an action is now urgently required in this country.

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The Analysis of the Current Status of Medical Accidents and Disputes Researched in the Korean Web Sites (인터넷 사이트를 통해 살펴본 의료사고 및 의료분쟁의 현황에 관한 분석)

  • Cha, Yu-Rim;Kwon, Jeong-Seung;Choi, Jong-Hoon;Kim, Chong-Youl
    • Journal of Oral Medicine and Pain
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    • v.31 no.4
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    • pp.297-316
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    • 2006
  • The increasing tendency of medical disputes is one of the remarkable social phenomena. Especially we must not overlook the phenomenon that production and circulation of information related to medical accidents is increasing rapidly through the internet. In this research, we evaluated the web sites which provide the information related to medical accidents using the keyword "medical accidents" in March 2006, and classified the 28 web sites according to the kinds of establishers. We also analyzed the contents of the sites, and checked and compared the current status of the web sites and problems that have to be improved. Finally, we suggested the possible solutions to prevent medical accidents. The detailed results were listed below. 1. Medical practitioners, general public, and lawyers were all familiar with and prefer the term "medical accidents" mainly. 2. In the number of sites searched by the keyword "medical accidents", lawyer had the most sites and medical practitioners had the least ones. 3. Many sites by general public and lawyers had their own medical record analysts but there was little professional analysts for dentistry. 4. General public were more interested in the prevention of medical accidents but the lawyers were more interested in the process after medical accidents. The sites by medical practitioners dealt with the least remedies of medical accidents, compared with other sites. 5. General public wanted the third party such as government intervention into the disputes including the medical dispute arbitration law or/and the establishment of independent medical dispute judgment institution. 6. In the comparison among the establishers of web sites, medical practitioners dealt with the least examples of medical accidents. 7. The suggestion of cases in counseling articles related to dental accidents were considered less importantly than the reality. 8. Whereas there were many articles about domestic cases related to the bloody dental treatment, in the open counseling articles the number of dental treatment regarding to non insurance treatment was large. 9. In comparing offered information of medical accidents based on the establishers, general public offered vocabularies, lawyers offered related laws and medical practitioners offered medical knowledge relatively. 10. They all cited the news pressed by the media to offer the current status of domestic medical accidents. Especially among the web sites by general public, NGOs provided the plentiful statistical data related to medical accidents. 11. The web sites that collect the medical accidents were only two. As a result of our research, we found out that, in the flood of information, medical disputes can be occurred by the wrong information from third party, and the medical practitioners have the most passive attitudes on the medical accidents. Thus, it is crucial to have the mutual interchange and exchange of information between lawyer, patients and medical practitioners, so that based on clear mutual comprehension we can solve the accidents and disputes more positively and actively.

Developing a Scale for Measuring the Corporate Social Responsibility Activities of Korea Corporation: Focusing on the Consumers' Awareness (한국형 기업의 사회적 책임활동 측정을 위한 척도 개발 연구: 소비자 인식을 중심으로)

  • Park, Jongchul;Kim, Kyungjin;Lee, Hanjoon
    • Asia Marketing Journal
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    • v.12 no.2
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    • pp.27-52
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    • 2010
  • It is not new that today's business organizations are expected to exhibit ethical and moral management and to carry out social responsibility as a good corporate citizen. Since South Korea emerged as a newly industrialized country during the 1980s, Korean corporations have become active in carrying out their social responsibility as a good corporate citizen to society. In spite of the short history of corporate social responsibility, Korean companies have actively participated in corporate philanthropy. Corporations' significant donations to various social causes, no-lay-off policies, corporate volunteerism and green marketing are evidences of their commitment to corporate citizenship. Corporate social responsibility is now an essential management practice whereby corporation can strengthen its sustainable value creation processes by enhancing the trust assets underlying the relationships between the business and the stakeholders. Much of the conceptual work in the area of corporate social responsibility(CSR) has originated from researches conducted in the management field. Carroll(1979) proposed that corporations have four types of social responsibilities: economic, legal, ethical and philanthropic responsibility. Most past research has investigated CSR and its impact on consumers' attitudes toward the corporations and corporate performances. Although there exists a large body of literature on how consumers perceive and respond to CSR, the majority of past studies were conducted in the United States. The stability and applicability of past findings need to be tested across different national/cultural settings, especially since corporate social responsibility is a reflection of implicit conformation with the expectations and criticism that society may have toward a corporation(Matten and Moon, 2004). In this study, we explored whether people in Korea perceive CSR of Korean corporations in the same four dimensions as done in the United States and what were the measurement items tapping each of these four dimensions. In order to investigate the dimensions of CSR and the measurement items for CSR perceived by Korean people, nine focus group interviews were conducted with several stakeholder groups(two with undergraduate students, two with graduate students, three with general consumers, and two with NGO groups). Scripts from the interviews revealed that the Korean stakeholders perceived four types of CSR which are the same as those proposed by Carroll(1979). However we found CSR issues unique to Korean corporations. For example for the economic responsibility, Korean people mentioned that the corporation needed to contribute to the economic development of the country by generating corporate profits. For the legal responsibility, Koreans included the "corporation need to follow the consumer protection law." For the ethical responsibility, they considered that the corporation needed to not promote false advertisement. In addition, Koreans thought that an ethical company should do transparent management. For the philanthropic responsibility, people in Korea thought that a corporation needed to return parts of its profits to the society for the betterment of society. The 28 items were developed based on the results of the nine focus group interviews, while considering the scale developed by Maignan and Ferrell(2001). Following the procedure proposed by Churchill(1979), we started by developing an item poll consisting of 28 items and purified the initial pool of items through exploratory, confirmatory factor analyses. 176 samples were sued for this analysis. Confirmatory factor analysis was performed on the 28 items in order to verify the underlying four factor structure. Study 1 provided new measurement items for tapping the Korean CSR dimensions, which can be useful for the future studies exploring the effects of CSR on Korean consumers' attitudes toward the corporations and corporate performances. And we found the CSR scale(17 items) has good reliability, discriminant validity and nomological validity. Economic Responsibility: "XYZ company continuously improves the quality of our products", "XYZ company has a procedure in place to respond to customer complaint", "XYZ company contributes to the economic development of our country by generating profits", "XYZ company is eager to hire people". Legal Responsibility: "XYZ company's products meet legal standards", "XYZ company seeks to comply with all laws regulating hiring and employee benefits", "XYZ company honors contractual obligations to its suppliers", "XYZ company's managers try to comply with the law related to the business operation". Ethical Responsibility: "XYZ company has a comprehensive code of conduct", "XYZ company does not promote a false or misleading advertisement", "XYZ company seems to conduct a transparent business", "XYZ company does a fair business with its suppliers or sub-contractors". Philanthropic Responsibility: "XYZ company encourages partnerships with local businesses and schools", "XYZ company supports sports and cultural activities", "XYZ company gives adequate contributions to charities considering its business size", "XYZ company encourages employees to support our community". Study 2 was condusted for comprehensive validity. 655 samples were used for this anlysis. Collected samples were tested by factor analysis and Crnbach's Alpha coefficiednts and were found to be satisfactory in terms of validity and reliability. Furthermore, fitness of the measurement model was tested by using conformatory factor analysis. χ2=880.73(df=160), GFI=0.891, AGFI=0.854, NFI=0.908, NNFI=0.913, RMR=0.059, RMESA=0.070. We hope that CSR scale could greatly facilitate research on Corporate social resposibility, it is by no means the final answer.

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