• Corrosion Science and Technology
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• 제14권2호
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• pp.54-58
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• 2015

A heavy oil of low quality has been mainly used in the diesel engine of the merchant ship as the oil price has been significantly jumped for several years. Thus, a combustion chamber of the engine has been often exposed to severely corrosive environment more and more because temperature of the exhaust gas of the combustion chamber has been getting higher and higher with increasing of using the heavy oil of low quality. As a result, wear and corrosion of the engine parts such as exhaust valve, piston crown and cylinder head surrounded with combustion chamber are more serious compared to the other parts of the engine. Therefore, an optimum repair welding for these engine parts is very important to prolong their lifetime in a economical point of view. In this study, 1.25Cr-0.5Mo filler metal was welded with SMAW method in the forged steel which would be generally used with piston crown material. And the corrosion properties of weld metal, heat affected and base metal zones were investigated using electrochemical methods such as measurement of corrosion potential, anodic polarization curves, cyclic voltammogram and impedance etc. in 35% $H_2SO_4$ solution. The weld metal and base metal zones exhibited the highest and lowest values of hardness respectively. And, the corrosion resistance of the heat affected and weld metal zones was also increased than that of the base metal zone. Furthermore, it appeared that the corrosive products with red color and local corrosion like as a pitting corrosion were more frequently observed on the surface of the base metal zone compared to the heat affected and weld metal zones. Consequently, it is suggested that the mechanical and corrosion characteristics of the piston crown can be predominantly improved by repair welding method using the 1.25Cr-0.5Mo electrode.

• 해양환경안전학회지
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• 제18권3호
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• pp.243-252
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• 2012

이 연구는 2010 마닐라 개정을 적용한 필리핀 해기 교육 및 훈련의 STCW 78/95의 이행여부를 검토한다. 또한 각국의 해사환경, 해기교육의 구조와 질, 해기인적 자원의 효과에 대해 논한다. 2010 마닐라 회의에서 채택한 다양한 결의안 중에서, 이 논문에서는 훈련과 증명의 기준 및 기술과 역량 증진에 대해 강조한다. 이는 필리핀고등교육위원회(CHED)에 의해 위임된 기존의 교과과정과 해사훈련위원회(MTC)에 의해 향상된 STCW 훈련을 비교할 것이며, 다른 아시아 국가에서의 해기 훈련에 대해서도 비교 분석할 것이다. 해기교육기관의 자격과 평가에 대한 현재 해사 제도의 약점을 지적한다. 이 연구에서는 미래에 유능한 인적자원 개발 측면에서 상호 채택 가능한 평가기준이 필요하다고 결론짓고 있다.

• 보건교육건강증진학회지
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• 제7권1호
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• pp.54-63
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• 1990

This study aims to find out the prevalence of smoking, and to analyze the effect of smoking for health status, and then to emphasize the necessity of stop smoking. The data used in this study are obtained from periodic health care programe at Health Care Center in a suburban hospital, and selected 435 males who have occupation. The independent varibles chosen for the analysis are general charactersitic variables and smoking habit. The dependent variables are designed to cover the health status of individual cases, and include blood pressure, blood cholesterol level with HDL-cholesterol and blood triglyceride level, recent symptoms and recently being managed diseases. The result of this study are summarized as follows. 1) Percentage of smoker by the age groups is highest in 4th decade, being 71.1%. The second and third ranks are 6th and 7th decades, being 53.5% and 44.4%, respectively. 2) In the view of socio-economic levels, smoking rate is higher in the groups who live at rural area and whoes occupation is labor or merchant. Smoking rate is significantly higher in the heavy drinking group. 3) Among the atherosclerotic risk factors, which include hypertension, HDL-cholesterol by total cholesterol ratio lower than 0.2 and triglyceride level higher than 200gm/dl, hypertension was not statistically associated with smoking, but others revealed statistically high association with smoking. 4) The groups who have the symptoms of severe fatigue, gastrointestinal symptoms, pulmonary symptoms, palpitation and chest tightness havepositive association with smoking. 5) The groups who have hypertension with cardiovascular diseases and gastrointestinal diseases showed highly significant association with non-smoking. 6) In relation of the smoking habit to the atherosclerotic risk factor index, smokers have more atherosclerotic risk factors, but that is not statistically significant. 7) In relation of the smoking habit to the recent symptom index, smokers have more symptoms than non-smokers with statistical significance. In conclusion, smokers have worse health status than non-smokers especially in the atherosclerotic risk factors such as hypertension or abnormal blood lipid status and have more symptoms such as severe fatigue, gastrointestinal symptoms, pulmonary symptoms, palpitation and chest tightness. And the campaingn against smoking should direct for the male in 4th decade because they have highest smoking rate.

• 한국해양공학회지
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• 제22권3호
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• pp.82-88
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• 2008

The diesel engine of the merchant ship has been aperated in severe environments more and more, because the temperature of the exhaust gas of a combustion chamber is getting higher and higher with increasing use of heavy oil of law quality, due to the significant increase in the price of oil in recent some years. As a result, the degree of wear and corrosion between exhaust valve and seat ring is more serious compared to other engine parts. Thus the repair welding of exhaust valve and seat ring is a unique method to prolong the life of the exhaust valve, from an economical point of view. In this study, the corrosion property of both weld metal and base metal was investigated using electrochemical methods such as measurement of corrosion potential, cathodic and anodic polarization curves, cyclic voltammogram, and polarization resistance in 5% H2SO4 solution. The test specimen was a part of an exhaust valve stem being welded as the base metal, using various welding methods. In all cases, the corrosion resistance as well as hardness of the weld metal zone was superior to the base metal. In particular, plasma welding showed relatively good properties for both corrosion resistance and hardness, compared to other welding methods. In the case of DC SMAW (Shielded metal arc welding), corrosion resistance of the weld metal zone was better than that of the base metal, although its hardness was almost same as the base metal.

• Asia pacific journal of information systems
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• 제23권4호
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• pp.103-128
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• 2013

When a consumer needs a product or service and multiple sellers are available online, the process of selecting a seller to buy online from is complex since the process involves many behavioral dimensions that have to be taken into account. As a part of this selection process, consumers may set minimum trust expectation that can be used to screen out less trustworthy sellers. In the previous research, the level of consumers' trust expectation has been anchored on two important factors: product involvement and perceived risk. Product involvement refers to the extent to which a consumer perceives a specific product important. Thus, the higher product involvement may result in the higher trust expectation in sellers. On the other hand, other related studies found that when consumers perceived a higher level of risk (e.g., credit card fraud risk), they set higher trust expectation as well. While abundant research exists addressing the relationship between product involvement and perceived risk, little attention has been paid to the integrative view of the link between the two constructs and their impacts on the trust expectation. The present paper is a step toward filling this research gap. The purpose of this paper is to understand the process by which a consumer chooses an online merchant by examining the relationships among product involvement, perceived risk, trust expectation, and intention to buy from an e-tailer. We specifically focus on the mediating role of perceived risk in the relationships between enduring product involvement and the trust expectation. That is, we question whether product involvement affects the trust expectation directly without mediation or indirectly mediated by perceived risk. The research model with four hypotheses was initially tested using data gathered from 635 respondents through an online survey method. The structural equation modeling technique with partial least square was used to validate the instrument and the proposed model. The results showed that three out of the four hypotheses formulated were supported. First, we found that the intention to buy from a digital storefront is positively and significantly influenced by the trust expectation, providing support for H4 (trust expectation ${\rightarrow}$ purchase intention). Second, perceived risk was found to be a strong predictor of trust expectation, supporting H2 as well (perceived risk ${\rightarrow}$ trust expectation). Third, we did not find any evidence of direct influence of product involvement, which caused H3 to be rejected (product involvement ${\rightarrow}$ trust expectation). Finally, we found significant positive relationship between product involvement and perceived risk (H1: product involvement ${\rightarrow}$ perceived risk), which suggests that the possibility of complete mediation of perceived risk in the relationship between enduring product involvement and the trust expectation. As a result, we conducted an additional test for the mediation effect by comparing the original model with the revised model without the mediator variable of perceived risk. Indeed, we found that there exists a strong influence of product involvement on the trust expectation (by intentionally eliminating the variable of perceived risk) that was suppressed (i.e., mediated) by the perceived risk in the original model. The Sobel test statistically confirmed the complete mediation effect. Results of this study offer the following key findings. First, enduring product involvement is positively related to perceived risk, implying that the higher a consumer is enduringly involved with a given product, the greater risk he or she is likely to perceive with regards to the online purchase of the product. Second, perceived risk is positively related to trust expectation. A consumer with great risk perceptions concerning the online purchase is likely to buy from a highly trustworthy online merchant, thereby mitigating potential risks. Finally, product involvement was found to have no direct influence on trust expectation, but the relationship between the two constructs was indirect and mediated by the perceived risk. This is perhaps an important theoretical integration of two separate streams of literature on product involvement and perceived risk. The present research also provides useful implications for practitioners as well as academicians. First, one implication for practicing managers in online retail stores is that they should invest in reducing the perceived risk of consumers in order to lower down the trust expectation and thus increasing the consumer's intention to purchase products or services. Second, an academic implication is that perceived risk mediates the relationship between enduring product involvement and trust expectation. Further research is needed to elaborate the theoretical relationships among the constructs under consideration.

• 유통과학연구
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• 제12권2호
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• pp.17-25
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• 2014

Purpose - This study used empirical methods to investigate the consciousness structure of vendors in the S marketing area, which is a commercial revitalization district in the country, and examined its effect on their business activities. Based on the results derived through the performance of an actual proof analysis, this study aims to facilitate the promotion of changes in the consciousness structures of traditional market vendors, with a view to allowing them to adapt to the current economic realities in the country. Further, this study aims to provide suggestions that would improve the efficiency of the commercial revitalization program of the government. Research design, data, and methodology - This study examined all the stores in the S marketing area using a questionnaire survey conducted over three weeks beginning on July 4, 2012, and involved the performance of a data analysis on 1,859 samples. The questionnaire consisted of two parts. The first part addressed the market revitalization and the second part addressed the store management strategies. Questionnaire responses were calibrated based on a Likert scale. Statistical analysis was conducted using PASW version 18.0. Results - The results of the analysis of the consciousness structure of merchants in the S marketing area have led to the discovery that they have a medium level of satisfaction with market revitalization. There was a difference in the perceptions of the concept of store management between merchants and customers. Merchants have poor strategies for store management, which do not go much beyond an imitation of the practices of large domestic discount stores. Conclusions - The appearance of big discount stores and the accompanying changes in people's consumption patterns have led to a decline in local market areas. The government has sought new ways to secure autogenic power for local markets. To create regional economies, the government enacted a revised "Law for creating traditional markets and shopping streets" in 2010 and introduced a commercial district revitalization program. This program, which originally supported only the S marketing area, has subsequently expanded into neighboring shopping districts so that the whole of the regional market can be revitalized. However, since the revitalization of the traditional market and the government support required for it were mostly limited to facilities, the result has not proved to be effective. Although there are several reasons why the government investment was characterized by poor efficiency, traditional market vendors' consciousness structure, which did not adapt well to the vagaries of time and its consequent changes, was a major cause. Only when vendors have a true merchant spirit can they have a real service focus that will enable them to clearly understand the distribution organization. This will have the effect of bring about complete customer satisfaction and will ensure the survival and development of traditional markets.

• Journal of Advanced Marine Engineering and Technology
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• 제39권5호
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• pp.542-547
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• 2015

Since the oil price has been significantly jumped for several years, a heavy oil of low quality has been mainly used in the diesel engine of the merchant ship. Thus, a combustion chamber of the engine has been often exposed to severely corrosive environment more and more because temperature of the exhaust gas of the combustion chamber has been getting higher and higher with increasing of using the heavy oil of low quality. As a result, wear and corrosion of the engine parts such as exhaust valve, piston crown and cylinder head surrounded with combustion chamber are more serious compared to the other parts of the engine. Therefore, an optimum repair welding for these engine parts is very important to prolong their lifetime in a economical point of view. In this study, Inconel 625 filler metal were welded with GTAW method in the cast steel which would be generally used with piston crown material. And the corrosion properties of weld metal, heat affected and base metal zones were investigated using electrochemical methods such as measurement of corrosion potential, anodic polarization curves, cyclic voltammogram and impedance etc. in 35% $H_2SO_4$ solution. The weld metal and base metal zones exhibited the highest and lowest values of hardness respectively. Furthermore, the corrosion current density of the weld metal zone revealed the lowest value, having the highest value of hardness. The corrosive products with red color and local corrosion like as a pitting corrosion were considerably observed at the base metal zone, while these morphologies were not wholly observed in the weld metal zone. In particular, the polarization characteristics such as impedance, polarization curve and cyclic voltammogran associated with corrosion resistance property were well in good agreement with each other. Consequently, it is suggested that the mechanical and corrosion characteristics of the piston crown can be predominantly improved by repair welding method using the Inconel 625 electrode.

• Journal of Advanced Marine Engineering and Technology
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• 제38권4호
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• pp.409-417
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• 2014

최근 수년 동안 유가의 현저한 상승으로 인하여 상선의 디젤 기관은 저질 중유를 주로 사용하게 되었다. 따라서 저질 중유의 사용 증가에 따른 디젤 기관의 연소실 배기가스 온도는 점차 상승하여 가혹한 부식 환경에 직면하게 되었다. 그 결과 연소실 주변의 모든 기관 부품들의 부식과 마모는 다른 기관 부품들에 비해서 심각하다. 그러므로 이들 부품들의 적절한 덧살 용접은 수명 연장을 위하여 경제적인 측면에서 매우 중요하다. 본 연구에서는 피스톤 크라운 재질로 통상 사용되는 단강에 4종류의 용접재료로 SMAW와 GTAW로 용접하였다. 실험은 모재, 열영향부 및 용접금속의 부식 특성을 35% 황산용액에서 부식전위, 양극분극 곡선, 사이클릭볼타모그램 및 임피던스 등의 전기화학적인 방법으로 하여 고찰하였다. Inconel 625, 718 용접재료의 경우 용접금속의 내식성이 가장 우수하였고, 모재의 내식성이 가장 좋지 않았으며, 반면에 1.25Cr-0.5Mo와 0.5Mo는 모재가 용접금속에 비해서 더 좋은 내식성을 나타내었다. 또한, 용접금속 중 Inconel 625가 가장 내식성이 우수하였으며, 그 다음으로 Inconel 718 용접재료로 나타났다. 경도 역시 용접금속이 상대적으로 모재, 열영향부에 비해서 높은 값을 나타내었다. 특히 Inconel 718 용접재료의 경우 다른 용접재료에 비하여 가장 높은 경도값을 나타내었다.

• 한방안이비인후피부과학회지
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• 제12권1호
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• pp.396-407
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• 1999

Although tinnitus is a common disease, it's reason, pathogenesis and treatment are not examined clearly. As tinnitus is a subjective complaint, it is not easy to evaluate objectively and to compare with another. In this study, we intend to estimate the effect of a variety of oriental medical treatments to tinnitus. We inquired about 30cases of tinnitus patients visited the Kwang-ju Oriental Medical Hospital of Wonkwang University from Apr. 1998 to Sep. 1998. We examined the 30cases in the view of sex, age, occupation, duration, etiologic factors, past history, associating symptoms, quality of tinnitus, and recovery rate after treatments. The results were as follows: 1. In distribution of sex, the ratio of male was $63.3\%$(19cases)and\;female\;was\;36.6\%$(11cases). 2. In distribution of age, the ratio of the 2th decade was $6.6\%(2cases),\;the\;3th\;decade\;was\;20.0\%(6cases),\;the\;4th\;decade\;was\;16.6\%(5cases),\;the\;5th\;decade\;was\;23.3\%(7cases),\;the\;6th\;decade\;was\;30.0\%\;(9cases),and\;the\;7th\;decade\;was\;3.3\%(1case)$. 3. In distribution of occupation, the ratio of employee was $23.3\%$(7cases), house-keeper was $63.3\%(11cases),\;farmer\;was\;16.6\%(5cases),\;teacher\;was\;13.3\%$ (4cases), and student, merchant, soldier was each $3.3\%$(1case). 4. In distribution of duration, the ratio of under 1month was $6.6\%$ (2cases), 1 month -6 months was $20.0\%$(6cases), 6 months- 12months was $30.0\%$(9cases), 12months-36months was $23.3\%$(7cases), and over 36months was $20.0\%$(6cases). 5. In etiologic factor of tinnitus, the ratio of unknown reason was $40.0\%$ (12cases), overwork was $16.6\%$(5cases), emotional stress was $10.0\%$(3cases), noise was $6.6\%$(2cases), cases of laying overwork upon stress was $13.3\%$(4cases), head trauma was $3.3\%$(1case), gun report was $3.3\%$ (1case), and after sickness was $6.6\%$(2cases). 6. 9 cases had experienced such a disease as meniere's disease, tympanitis, labyrinthitis, trauma of tympanum, hypertension, etc. 7. Commonly associated symptoms were dizziness, deafness, uneasiness, headache, ear fullness, fatigue, insomnia, nausea, vomiting, and forgetfulness. 8. Most frequent quality of tinnitus were buzzing, whistling, humming etc. 9. In $76.6\%$(23cases) of tinnitus patients, it was improved, but in $23.3%$(7cases) of them, not improved. Total recovery rate was $42.2\%$.

• 산경연구논집
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• 제13권6호
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• pp.39-49
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• 2022

Purpose: As part of these efforts, in-depth research is needed on efficient and practical utilization of underground spaces and underground shopping malls. In addition, efforts are being made to find effective alternatives to various problems currently occurring in underground shopping malls, but it is not easy. In addition, the development entity and the maintenance entity are different from each other, and the management is not unified, making it difficult to maintain underground shopping malls. From this point of view, it can be said that it is time to actively and specifically discuss ways to revitalize underground shopping malls. Data and methodology: In the domestic distribution environment, traditional markets and shops are stagnating due to rapid changes in consumption patterns, such as the spread of large companies with advanced distribution techniques such as hypermarkets, shopping malls, and SCM, the rapid increase in Internet and home shopping, and the importance of convenience for young consumers. In order to revitalize underground shopping malls, it is necessary to strengthen the organization and self-rescue efforts of merchants' associations, change consciousness through merchant education, change to specialized markets, find nuclear stores and representative restaurants, and support the hardware sector. Results: The connection of underground shopping malls in each region of the country, where commercial districts are separated from each other, will also play an important role in reviving the function of the city in the future. To do this, it is first necessary to connect underground shopping malls that have been cut off. In other words, connection between connectable underground shopping malls should be promoted. Of course, long-term projects should be promoted step by step, and many consultations should be made on how to connect with the ground for each local government. Conclusion: This is because in the future, the underground space cannot just be a walking place, but another space of the Korean Wave where you can experience satisfying the five senses. K-shopping Hallyu content can be created by creating a characteristic story for each underground shopping mall in the city, permanently this story-oriented event, and creating a safe and elegant environment. If there is a story, so-called "Senomi Shopping" will be possible. A new Korean Wave will be created that can satisfy "the fun of writing, the fun of seeing, and the fun of feeling" at the same time.