• Title/Summary/Keyword: contact effect

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Evaluation of Bonding Performance of Hybrid Materials According to Laser and Plasma Surface Treatment (레이저 및 플라즈마 표면처리에 따른 이종소재 접합특성평가)

  • Minha Shin;Eun Sung Kim;Seong-Jong Kim
    • Composites Research
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    • v.36 no.6
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    • pp.441-447
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    • 2023
  • Recently, as demand for high-strength, lightweight materials has increased, there has been great interest in joining with metals. In the case of mechanical bonding, such as bolting and riveting, chemical bonding using adhesives is attracting attention as stress concentration, cracks, and peeling occur. In this paper, surface treatment was performed to improve the adhesive strength, and the change in adhesive strength was analyzed. For the adhesive strength test were conducted with Carbon Fiber Reinforced Plastic(CFRP), CR340(Steel), and Al6061(Aluminum), and laser and plasma surface treatment were used. After plasma surface treatment, the adhesive strength improved by 7.3% and 39.2% in CFRP-CR340 and CFRP-Al6061, respectively. CR340-Al6061 was improved by 56.2% in laser surface treatment. Surface free energy(SFE) was measured by contact angle after plasma treatment, and it is thought that the adhesion strength was improved by minimizing damage through a chemical reaction mechanism. For laser surface treatment, it is thought that creates a rough bonding surface and improves adhesive strength due to the mechanical interlocking effect. Therefore, surface treatment is effect to improve adhesive strength, and based on this paper, the long-term fatigue test will be conducted to prevent fatigue failure, which is a representative cause of actual structural damage.

Effect of Compensation for Thickness Reduction by Chemical Degradation of PEMFC Membrane on Performance and Durability (PEMFC 고분자막의 화학적인 열화에 의한 두께 감소 보정이 성능 및 내구성에 미치는 영향)

  • Sohyeong Oh;Yoojin Kim;Seungtae Lee;Donggeun Yoo;Kwonpil Park
    • Korean Chemical Engineering Research
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    • v.62 no.1
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    • pp.1-6
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    • 2024
  • As the demand for hydrogen electric vehicles for commercial vehicles increases, the durability of PEMFCs must increase more than five times that of passenger cars, so research and development to improve durability is urgent. When the PEMFC membrane electrode assembly (MEA) undergoes chemical degradation, the MEA thickness decreases and pinholes occur. In this study, changes in the performance and durability of the MEA were measured while increasing the clamping pressure of the unit cell after open circuit voltage (OCV) holding, an accelerated chemical degradation experiment. As the clamping pressure increased, the resistance of the polymer membrane and the membrane/electrode contact resistance decreased, improving the I-V performance and reducing the hydrogen permeability. As the hydrogen permeability decreased, the OCV increased. When the pinhole area was removed and the MEA clamping pressure was increased, the hydrogen permeability decreased sharply, confirming that the local degradation has a large effect on the performance and durability of the entire cell. When the pinhole was removed and re-clamping and OCV holding was evaluated, it was confirmed that the durability improved according to the decrease in membrane resistance and hydrogen permeability.

Study on the Influencing Factors of Business Performance and Loyalty in O2O Industry: Focusing on the Food Delivery Apps (O2O 플랫폼 품질이 자영업자의 디지털 전환에 미치는 영향: 배달앱을 중심으로)

  • Dae Yong Hyun;Sun-Young Kim;Byungheon Lee
    • Asia-Pacific Journal of Business
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    • v.15 no.1
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    • pp.193-207
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    • 2024
  • Purpose - With the increase of non-face-to-face activities due to the spread of COVID-19, O2O industry has grown rapidly which reduces contact points between suppliers and consumers. O2O platform is now recognized as an indispensable channel of distribution, but the voice is getting louder that it is necessary to check how it contributes to the performance of suppliers or how its fee system or contract terms affects the expansion of O2O industry as the leading companies tend to monopolize the market. Design/methodology/approach - In this study, the scope was limited to the restaurant industry in which transactions are the most active among the O2O industry and a regression analysis was done on 775 businesses that had used guarantor service from the Seoul Credit Guarantee Foundation. Findings - Analysis on the impact of O2O platform system, information, and service quality on the business performance of the sole proprietors revealed that the system quality represented by ease of use and the information quality determined by level of timely, accurate and reliable information provided to the consumers have a statistically significant effect on the improvement of business performance. In addition, the effect of business performance on the loyalty measured by the likelihood of users continuing to use the service as well as recommending it to others was moderated by the satisfaction with contract terms, not by the fee system. Research implications or Originality - Although the number of O2O platform providers has increased manyfold, the membership rate is no more than 20%, which means that the small business owners are still struggling with digital transformation. In order for the O2O industry, which is now commonplace, to form a healthy ecosystem that satisfies both suppliers and consumers, the standard contract guidelines that are acceptable to both parties must be established and the O2O providers must offer services that help suppliers to improve performance.

Controlling effect of environmentally friendly organic materials on the black rice bug, Scotinophara lurida(Hemiptera: Pentatomidae), depending on paddy flooding (논 담수 여부에 따른 유기농업자재의 먹노린재 방제 효과)

  • You Kyoung Lee;Nak-Jung Choi;Ju-Rak Lim;Jun-Yeol Choi;Bo Yoon Seo
    • Korean Journal of Environmental Biology
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    • v.41 no.4
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    • pp.463-472
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    • 2023
  • The insecticidal activities of 27 different commercial products with environmentally friendly organic material(EFOM) against Scotinophara lurida, a major rice pest, were evaluated in the laboratory using spraying methods on plants and insects. Seven plant-derived organic farming materials (EFOM-8, -10, -12, -13, -19, -20, and -26) with high insecticidal effects when sprayed directly on the insect's body rather than on the plant were selected. In the indoor rice pot test, all 7 EFOMs showed an insecticidal rate of over 73.3% under flooding conditions. Notably, EFOM-13 and EFOM-20 demonstrated much higher insecticidal rates, ranging from 1.5 to 1.8 times, in flooding conditions compared to drained conditions. In the semi-paddy field test, EFOM-10 (80% garlic extract), EFOM-13 (62% neem extract), and EFOM-26 (70% sophora extract+28% ethyl alcohol+2% pyrethrum extract) exhibited a higher control value of 88.9% in the irrigated paddy on the 7th day, surpassing the control values in the drained paddy by 1.4 to 1.9 times. The control value in the irrigated rice paddy field sprayed with EFOM-10 reached 86.2% on the 7th day, which was 1.4 times higher than 61.9% in the drained paddy. Taken together, the findings suggest that direct contact of the insect's body with sufficient amounts of spray solution and the maintenance of paddy irrigation can enhance the controlling effect of EFOMs. These findings will be valuable in developing an optimal S. lurida control strategy for application in rice paddy fields in the near future.

INHIBITORY EFFECT OF Er:YAG LASER ON THE GROWTH OF STREPTOCOCCUS MUTANS (Er:YAG 레이저 조사가 Streptococcus mutans의 증식억제에 미치는 효과)

  • Song, Gwang-Chul;Lee, Chang-Seop;Lee, Sang-Ho;Lee, Nan-Young
    • Journal of the korean academy of Pediatric Dentistry
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    • v.30 no.1
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    • pp.15-24
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    • 2003
  • The purpose of this study is to investigate the sterilization effect of Er:YAG laser against the intraoral acid producing bacterium, S. mutans, by irradiating the culture solution containing S. mutans KCTC 3065 with Er:YAG laser having a $650{\mu}m$ diameter beam through the non-contact method. We obtained the following results after examining the temperature changes of the culture solution, numbers of bacterial colonies, and acid-producing ability and attaching ability on teeth by measuring the amount of extracellular polysaccharide produced by S. mutans. The number of bacterial colony was decreased in $10{\mu}l$ culture solution irradiated with laser in overall compared to the control solution. The number decreased as the irradiation intensity and pulse repetition rate were larger and as the exposure time was increased. However, it did not change significantly in $100{\mu}l$ culture solution compared to the control solution. Although the acid-producing ability of S. mutans was inhibited for a certain duration after laser irradiation in 10r1 bacterial culture solution, it did not change in $100{\mu}m$ solution compared with the control solution. The amount of extracellular polysaccharide synthesized by S. mutans was partially decreased through laser irradiation in $10{\mu}m$ culture solution but did not change in $100{\mu}m$ culture solution. Based on these findings, we concluded that Er:YAG laser has an sterilization effect on S. mutans in which we presume that the mechanism is through the heat effect rather than the mechanical effect from development of ultrasound.

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A Study on the convenience store brands' ESG activities impact store loyalty: Focusing on the Moderating Effect of Eco-friendly Values, Social media Activity, Consumer-Company Identification (편의점의 ESG활동이 점포충성도에 미치는 영향: 친환경가치관, 소셜미디어활동성, 소비자-기업동일시의 조절효과)

  • Jeong-Ho Chun;Hyeon-Suk Park
    • Industry Promotion Research
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    • v.9 no.3
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    • pp.57-75
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    • 2024
  • This study examined how ESG activities of convenience stores, affect consumers' store loyalty. Using 300 valid samples of convenience store users collected through an online specialized agency (Company M), this study empirically analyzed the effects of environmental (E), social (S), and governance (G) activities among ESG on trust and store loyalty, and the mediating effects of trust and the moderating effects of eco-friendly values, social media activity, and consumer-company identification. The results of the analysis showed that, first, governance activities had a positive effect on trust, and environmental activities and trust had a positive effect on store loyalty, but social activities had no effect Second, trust had a moderating effect only on the relationship between governance activities and store loyalty, and third, in the relationship between ESG activities and trust, eco-friendly values and social media activity had moderating effects on environmental, social, and governance activities, and consumer-company identification had moderating effects on environmental and governance activities, but not on social activities. Therefore, convenience store brands should further strengthen their environmental and social activities to build consumer trust, especially environmental activities, which only directly affect store loyalty, so they should be more cautious and proactive. In addition, intensive marketing activities are needed to build trust among consumers who have high eco-friendly values, social media activity, and consumer-company identification. Therefore, this study confirms the critical view of consumers despite the social contribution activities of convenience store brands, and suggests that in order to improve them, it is necessary to strengthen social activity efforts, actively participate in ESG activities of on-site franchisees who are customer contact points, and educate employees.

A study on The U.S.-Korean Trade Friction Prevention and Settlement in the Fields of Information and Telecommunication Industries (한미간(韓美間) 정보통신분야(情報通信分野) 통상마찰예방(通商摩擦豫防)과 해소방안(解消方案)에 관한 연구(硏究))

  • Jung, Jay-Young
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.13
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    • pp.869-895
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    • 2000
  • The US supports the Information and Communication (IC) industry as a strategic one to wield a complete power over the World Market. However, several other countries are also eager to have the support for the IC industry because the industry produces a high added value and has a significant effect on other industries. Korea is not an exception. Korea recently succeeded in the commercialization of CDMA for the first time in the world, after the successful development of TDX. Hence, it is highly likely to get tracked by the US. Although the IC industry is a specific sector of IT, there is a concern that there might be a trade friction between the US and Korea due to a possible competition. It will be very important to prepare a solution in advance so that Korea could prevent the friction and at the same time increase its share domestically and globally. It will be our important task to solve the problem with the minimum cost if the conflict arises unfortunately in the IT area. The parties that have a strong influence on the US trade policy are the think tank group and the IT-related interest group. Therefore, it would be important to have a close relationship with them. We found some implications by analyzing the case of Japan, which has experienced trade frictions with the US over the long period of time in the high tech industry. In order to get rid of those conflicts with the US, the Japanese did the following things : (1) The Japanese government developed supporting theories and also resorted to international support so that the world could support the Japanese theories. (2) Through continual dialogue with the US business people, the Japanese business people sought after solutions to share profits among the Japanese and the US both in the domestic and in the worldwide markets. They focused on lobbying activities to influence the US public opinion to support the Japanese. The specific implementation plan was first to open culture lobby toward opinion leaders who were leaders about the US opinion. The institution, Japan Society, were formed to deliver a high quality lobbying activities. The second plan is economic lobby. They have established Japanese Economic Institute at Washington. They provide information about Japan regularly or irregularly to the US government, research institution, universities, etc., that are interested in Japan. The main objective behind these activities though is to advertise the validity of Japanese policy. Japanese top executives, practical interest groups on international trade, are trying to justify their position by direct contact with the US policy makers. The third one is political lobby. Japan is very careful about this political lobby. It is doing its best not to give impression that Japan is trying to shape the US policy making. It is collecting a vast amount of information to make a correct judgment on situation. It is not tilted toward one political party or the other, and is rather developing a long-term network of people who understand and support the Japanese policy. The following implications were drawn from the experience of Japan. First, the Korean government should develop a long-term plan and execute it to improve the Korean image perceived by American people. Second, the Korean government should begin public relation activities toward the US elite group. It is inevitable to make an effort to advertise Korea to this elite group because this group leads public opinion in the USA. Third, the Korean government needs the development of a relevant policy to elevate the positive atmosphere for advertising toward the US. For example, we need information about to whom and how to about lobbying activities, personnel network who immediately respond to wrong articles about Korea in the US press, and lastly the most recent data bank of Korean support group inside the USA. Fourth, the Korean government should create an atmosphere to facilitate the advertising toward the US. Examples include provision of incentives in tax on the expenses for the advertising toward the US and provision of rewards to those who significantly contribute to the advertising activities. Fifth, the Korean government should perform the role of a bridge between Korean and the US business people. Sixth, the government should promptly analyze the policy of IT industry, a strategic area, and timely distribute information to industries in Korea. Since the Korean government is the only institution that has formal contact with the US government, it is highly likely to provide information of a high quality. The followings are some implications for business institutions. First, Korean business organization should carefully analyze and observe the business policy and managerial conditions of US companies. It is very important to do so because all the trade frictions arise at the business level. Second, it is also very important that the top management of Korean firms contact the opinion leaders of the US. Third, it is critically needed that Korean business people sent to the USA do their part for PR activities. Fourth, it is very important to advertise to American employees in Korean companies. If we cannot convince our American employees, it would be a lot harder to convince regular American. Therefore, it is very important to make the American employees the support group for Korean ways. Fifth, it should try to get much information as early as possible about the US firms policy in the IT area. It should give an enormous effort on early collection of information because by doing so it has more time to respond. Sixth, it should research on the PR cases of foreign enterprise or non-American companies inside the USA. The research needs to identify the success factors and the failure factors. Finally, the business firm will get more valuable information if it analyzes and responds to, according to each medium.

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INHIBITORY EFFECT OF DENTAL LASERS ON THE GROWTH AND THE FUNCTION OF STREPTOCOCCUS MUTANS (각종 치과레이저의 Streptococcus mutans에 대한 증식 및 기능억제 효과)

  • Han, Kang-Seog;Kook, Joong-Ki;You, So-Young;Kim, Hwa-Sook;Park, Jong-Whi;Park, Heon-Dong;Lee, Sang-Ho
    • Journal of the korean academy of Pediatric Dentistry
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    • v.30 no.3
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    • pp.439-447
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    • 2003
  • This was performed to evaluate the inhibitory effect of laser on the growth of S. mutans. The bacterial pallets containing S. mutans KCTC 3065 were irradiated with Er:YAG laser and Nd :YAG laser by non-contact method at an intensity of 50mJ for 5 sec with the pulse repetition rates of 10Hz and 30Hz, respectively. The following results were obtained on colony count, acid producing ability, and the amount of insoluble extracellular polysaccharide synthesis. 1. The irradiation of Nd:YAG laser after photosensitization with Chinese ink inhibited the proliferation of S. mutans the most, and the irradiation of Er:YAG also inhibited the proliferation. However, the irradiation of Nd:YAG laser alone could not inhibited the proliferation of S. mutans. The pulse repetition rate did not affect significantly on the proliferation of bacteria in overall. 2. The irradiation of Nd:YAG laser after the photosensitization with Chinese ink inhibited the acid production of S. mutans the most for a certain period of time. Er:YAG laser also inhibited acid production. When Nd:YAG laser was used alone, the acid production of S. mutans was not been inhibited. The irradiation of Nd:YAG laser after photosensitization with Chinese ink inhibited the acid production ability of bacteria the most as the pulse repetition rate increased. 3. Laser irradiation did not inhibited the synthesis of insoluble extracellular polysaccharide of S. mutans. From these results, we conclude that the irradiation of Er:YAG laser and Nd:YAG laser after photosensitization with Chinese ink would inhibit the proliferation and acid production by S. mutans, which may prevent dental caries. However, this effect does not last long time so that the laser irradiation should be repeated frequently in order to obtain clinical effect; thus, this laser irradiation would not have a clinical usefulness in preventing dental caries when used solely.

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Mediating Effect of Customer Orientation and Customer Satisfaction Between Entrepreneurship and Financial Performance: Focusing on the Beauty Service Industry (기업가정신과 재무적 성과 간의 고객지향성, 고객만족의 매개효과: 미용 서비스산업 중심으로)

  • Kwak, jinman;Lee, sehee
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.16 no.6
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    • pp.197-211
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    • 2021
  • In the service industry the types are diversifying and the scale of service companies is greatly improving. Such a phenomenon is caused by economic growth and technological development diversifying consumer needs creating demand for new services maturing the service industry and intensifying competition among companies in the form of global competition. It can be said that this is because it is necessary to improve competitiveness by utilizing the economy of scale. Research is needed on the impact of entrepreneurship on various outcome variables in order for service organization managers to respond quickly to diverse and rapidly changing environments and achieve organizational outcomes and corporate goals of management outcomes. The purpose of this study was to empirically analyze the relationship in which the entrepreneurial spirit of a manager influences the relationship between customer orientation, which is an organizational result, customer satisfaction, and financial result, which is a management result. In order to verify such research, the questionnaire was composed of one business owner questionnaire, two employee questionnaires, and two customer questionnaires. The questionnaire was distributed to a total of 400 companies, and the questionnaires of 340 companies were collected. Of these, 303 companies, excluding the questionnaires of 37 companies with many dishonest or missing values, were used for hypothesis testing. The results of this study can be summarized as follows. First, entrepreneurship had a positive (+) effect on customer orientation, supporting the hypothesis. Second, customer orientation showed a positive (+) effect on customer satisfaction, supporting the hypothesis. Third, customer satisfaction showed a positive (+) effect on financial outcomes, supporting the hypothesis. Fourth, it was found that entrepreneurship influences customer satisfaction through customer orientation, and customer satisfaction affects financial outcomes. It turns out that customer orientation between entrepreneurship and customer satisfaction is completely mediated, and customer satisfaction is completely mediated by customer orientation and financial outcomes. The relationship between entrepreneurship and management improved employee behavior and attitudes, which is an individual outcome, and this change was found to improve customer satisfaction, which is an organizational outcome. It makes frequent contact with customers in the process of servicing them. Employee roles are important at service contacts and influence service purchases. Employees facing customers through service contacts act as a decisive factor in maintaining a continuous relationship with customers. Within a beauty service company, it is necessary to create a customer-oriented environment among workers. It suggests that customer-oriented companies and employees can anticipate their desires and provide products or services of superior value to achieve greater customer satisfaction and a competitive advantage. In addition, it was clarified that customer satisfaction has an aspect relationship with financial management, which is a management result. Therefore, it is suggested that the entrepreneurial spirit is an important factor for the management of a beauty service company to secure competitiveness and improve results.

The Causes of Conflict and the Effect of Control Mechanisms on Conflict Resolution between Manufacturer and Supplier (제조-공급자간 갈등 원인과 거래조정 방식의 갈등관리 효과)

  • Rhee, Jin Hwa
    • Journal of Distribution Research
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    • v.17 no.4
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    • pp.55-80
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    • 2012
  • I. Introduction Developing the relationships between companies is very important issue to ensure a competitive advantage in today's business environment (Bleeke & Ernst 1991; Mohr & Spekman 1994; Powell 1990). Partnerships between companies are based on having same goals, pursuing mutual understanding, and having a professional level of interdependence. By having such a partnerships and cooperative efforts between companies, they will achieve efficiency and effectiveness of their business (Mohr and Spekman, 1994). However, it is difficult to expect these ideal results only in the B2B corporate transaction. According to agency theory which is the well-accepted theory in various fields of business strategy, organization, and marketing, the two independent companies have fundamentally different corporate purposes. Also there is a higher chance of developing opportunism and conflict due to natures of human(organization), such as self-interest, bounded rationality, risk aversion, and environment factor as imbalance of information (Eisenhardt 1989). That is, especially partnerships between principal(or buyer) and agent(or supplier) of companies within supply chain, the business contract itself will not provide competitive advantage. But managing partnership between companies is the key to success. Therefore, managing partnership between manufacturer and supplier, and finding causes of conflict are essential to improve B2B performance. In conclusion, based on prior researches and Agency theory, this study will clarify how business hazards cause conflicts on supply chain and then identify how developed conflicts have been managed by two control mechanisms. II. Research model III. Method In order to validate our research model, this study gathered questionnaires from small and medium sized enterprises(SMEs). In Korea, SMEs mean the firms whose employee is under 300 and capital is under 8 billion won(about 7.2 million dollar). We asked the manufacturer's perception about the relationship with the biggest supplier, and our key informants are denied to a person responsible for buying(ex)CEO, executives, managers of purchasing department, and so on). In detail, we contact by telephone to our initial sample(about 1,200 firms) and introduce our research motivation and send our questionnaires by e-mail, mail, and direct survey. Finally we received 361 data and eliminate 32 inappropriate questionnaires. We use 329 manufactures' data on analysis. The purpose of this study is to identify the anticipant role of business hazard (environmental dynamism, asset specificity) and investigate the moderating effect of control mechanism(formal control, social control) on conflict-performance relationship. To find out moderating effect of control methods, we need to compare the regression weight between low versus. high group(about level of exercised control methods). Therefore we choose the structural equation modeling method that is proper to do multi-group analysis. The data analysis is performed by AMOS 17.0 software, and model fits are good statically (CMIN/DF=1.982, p<.000, CFI=.936, IFI=.937, RMSEA=.056). IV. Result V. Discussion Results show that the higher environmental dynamism and asset specificity(on particular supplier) buyer(manufacturer) has, the more B2B conflict exists. And this conflict affect relationship quality and financial outcomes negatively. In addition, social control and formal control could weaken the negative effect of conflict on relationship quality significantly. However, unlikely to assure conflict resolution effect of control mechanisms on relationship quality, financial outcomes are changed by neither social control nor formal control. We could explain this results with the characteristics of our sample, SMEs(Small and Medium sized Enterprises). Financial outcomes of these SMEs(manufacturer or principal) are affected by their customer(usually major company) more easily than their supplier(or agent). And, in recent few years, most of companies have suffered from financial problems because of global economic recession. It means that it is hard to evaluate the contribution of supplier(agent). Therefore we also support the suggestion of Gladstein(1984), Poppo & Zenger(2002) that relational performance variable can capture the focal outcomes of relationship(exchange) better than financial performance variable. This study has some implications that it tests the sources of conflict and investigates the effect of resolution methods of B2B conflict empirically. And, especially, it finds out the significant moderating effect of formal control which past B2B management studies have ignored in Korea.

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