• Transactions of Materials Processing
• /
• v.28 no.6
• /
• pp.361-367
• /
• 2019

Microstructure evolution and tensile properties of Al-8mass%Mg alloy casting billet by biaxial alternative forging were investigated in this study. An alternative forging system tailored in this study was used to allow continuous strain accumulations on the alloy workpiece. A finite element (FE) simulation results revealed that the strain was mainly concentrated in the core and that the shear bands developed into a form with an X shape in the cross-section of workpiece after the alternative forging using octangular rod shaped dies. With increasing the forging passes, it was observed that the Al-8mass%Mg alloy workpieces were significantly deformed, and cracks began to form and propagate on the both ends of the forged workpieces after five passes at room temperature. In as-forged microstructures taken by microscopes, twins, clustering of dislocations, and fine subgrains were found. Tensile strengths of the forged specimens showed significant increases depending on the number of forging passes, and a trade-off relationship was observed between the elongation and strength. At room temperature and 100℃ the workpieces showed similar behaviors in microstructural evolution and tensile properties depending on forging passes, while the increase range in strength was reduced at 200℃.

• Journal of Korea Port Economic Association
• /
• v.20 no.2
• /
• pp.131-149
• /
• 2004

With trend of container ships becoming larger and faster, the environment surrounding ports in North-East Asia is rapidly changing. Korea's largest port of Busan processed more than 10 million 20- feet equivalent containers in 2003, surpassing the 10-million TEU mark for the first time in its three decades of operation. However, the Port of Busan , the world's third-largest port in 2002, was eclipsed by Shanghai since July in 2003. The first massive strike of truckers crippled the Korea's logistics system in May and in September, the Port of Busan suffered from the second strike of truckers and damage by a powerful typhoon. By contrast, the port of Shenzhen in China increased its container-processing volume by 39.9 percent to 10.65 million TEU in 2003, and Shanghai, which passed Busan in terms of container volume in the middle of last year, further consolidated its position as the world's No. 3 port with an annual volume of 11.28 million TEU. After all, Busan recorded an annual container volume of 10.40 million TEU, slipping to fifth in rankings in 2003 and Busan's bid to become a Northeast Asian hub has suffered a further setback as these chinese ports overtook the port of Busan. But the port of Busan is located in the main trunk liking North America, Europe and South-East Asia. Once the project of Busan Newport is accomplished and the railway between South and North Korea is connected to TCR and TSR, the Port of Busan will have the most potential to become the international logistics center as the starting point of the land and sea routes encompassing all over the world.

• Journal of Dairy Science and Biotechnology
• /
• v.14 no.1
• /
• pp.43-56
• /
• 1996

The world dairy industry has been driving their dairy policy on the basis of the self-supportihg principle. With progressing the GATT negotiation, the objective production amount has been reduced to maintain the optimum level, which decreasing the extra supply and over-stock before the U.R talks. The Oceania countries, where has the price competition capability, are continually increasing the milk production amount. Even through the USA is trying to increase their production amount with new export policy, the U.S.S.R collapse-down caused to decrease the milk production in world-wide basis. Because the U.S.S.R produced the highest amount of milk in the world. Moreover Europe Union countries, which recorded the half amount of dairy products in the world was decreasing their milk production. Therefore, about 4% of shortage is encountering at major dairy production countries in the standpoint of supply and demand. The drastic increasement of foreign dairy product import affects the domestic dairy industry with raw milk replacement and new dairy food demands creation since 1995, the initial period of free import system. Now, the domestic dairy industry are facing the inevitable problems such as the correction of producting and processing system. First of all, our dairy industry should resettle down the dairy production structure on the basis of self-supply of raw milk and offer the accurate dairy food informations. We still need to improve the raw milk quality. Also, more efforts are needed to have proper raw milk price policy. General domestic policies including the settlement of raw milk supply and demand, the reliability of inspection system in raw milk, ideal raw milk price system, centralization of raw milk collection, specially separated dairy organization should be improved legally in our dairy industry.

• The KIPS Transactions:PartC
• /
• v.13C no.5 s.108
• /
• pp.583-594
• /
• 2006

The reliability concept of wireless sensor network is essential to get exactly actual data from the ubiquitous environment. A rollback technique for the self-healing helps to increase it. However, a fault can occur in wireless sensor network when to use a previous rollback technique because it is designed just for the local system. So, checkpoint protocols are suggested in order to use a rollback technique in the network without the fault. However, there is trade-off among performance overhead, power consumption, and memory overhead for each of protocols. Hence, we suggest a novel global checkpoint protocol, so called address log based protocol(ALBP), based on an asynchronous protocol. It is a platform based protocol to reduce power consumption, performance overhead, and memory overhead which are the most of consideration in wireless sensor network.

• The Journal of Fisheries Business Administration
• /
• v.39 no.1
• /
• pp.133-162
• /
• 2008

In 1970, direct overseas investment in Korean fisheries started to sell the frozen marine products to Singapore with establishing local subsidiary. Direct overseas investment in China has carried out since Korea and China established diplomat relationship in 1992. the former day, The Korea invested indirectly in China via Hong Kong. It has reported that 253 local subsidiaries applied to China government permit at the end of 2004. The results will make a decision on whether to invest continuously. The results of actual proof analysis has announced that a successful investment of fishery company is mainly influenced in its own government policy. Many advantages of tax and administration for foreign company in China have been changed and vanished comparing to the beginning time of entering china. So. it is imperative for Korean government to take measures to changing policy of Chinese government. The early days, investment of fishery company is type of resources and abundant resources will affect succeeding investment. Nowadays, the type of the investment is the production oriented investment. And then many direct investment linked the production oriented investment have been conducted in many area in China. So. the production oriented investment will affect logistics and successful investment in China. And, The factor of Market potential in Market Factors in the middle of changing market oriented investment will conclude whether to invest. As the china exchange system changed from the fixed exchange system to the fluctuating exchange system. Risk of exchange rate will affect corporate's parent business. The local risk (regulation of import and export, remittance) will affect succeeding investment of corporate's parent.

• The KIPS Transactions:PartD
• /
• v.10D no.3
• /
• pp.559-566
• /
• 2003

As cell phone and PDA have been in common use recently, there is a growing tendency to utilize the mobile terminals for M-Commerce. The information security and the receipt of e-trade are very important to support reliable digital transactions in wireless environment as in wired environment. Even though some work such as WML digital signature and WPKI has been studied for M-Commerce, there are several problems on the aspects of the functional limitation of the mobile terminals and the unsecure data transformation of WAP gateway. In this study we have designed and implemented a prototype system of issuing and verifying the electronic receipt that guarantees authentication, data integrity and non-repudiation for secure mobile e-commerce. Moreover, we have enhanced the system performance by letting the trusted independent server verify and manage the electronic receipt.

• KIPS Transactions on Software and Data Engineering
• /
• v.2 no.11
• /
• pp.747-756
• /
• 2013

It is important to reduce unnecessary overhead in sensor network using battery. In addition encryption is important because of necessity of security. Since unavoidable overhead occurs in case of encryption, security and overhead are in trade-off condition. In this paper, we use a concept called trust to reduce the encryption overhead. We reduce overhead by controlling encryption key sizes while maintaining the security level where high and low trust nodes are mixed. We simulated and compared normal encryption and trust value based encryption. As a result, the latter has lower execution time and overhead. If we define a standard of trust levels considering purpose and circumstances of real network, we can use constrained resources efficiently in sensor network.

• The Korean Journal of Community Living Science
• /
• v.17 no.3
• /
• pp.55-65
• /
• 2006

Recent trends of global food production, processing, distribution and preparation under free trade circumstance are creating an increase in common' concerns about food safety. It is important that farmers improve agricultural products/food safety for satisfying consumer needs and health. Cognizant to the situation, this study was conducted to analyze how the Producers gather information, and determine their awareness about agricultural Products safety using a safety Questionnaire. The Questionnaire was given to 500 farmers who cultivate rice, fruit trees, vegetables, and other crops from September through October 2005. More than half of the producers felt concerns about the agricultural products/foods safety. Uneasiness of the producers was higher amongst those who were younger and earned a higher income. Pesticides and zoonosis (BSE AI, etc.) emerged as the main risk factors causing concerns among the greatest number of producers. Producers had a positive opinion of the effects and perception of food safety, but no opinion of the activity of government. The producers showed a high level of understanding of the Country of Origin Labeling System (88.2%), the quality certification system of agricultural and livestock products (71.9%), and the raising system of environment-friendly agriculture (72.7%). However, their level of understanding of the GAP (59.3%) and the Traceability System (22.8%) was still low. To effectively implement these policies, awareness of producers who are the beneficiaries of the above policies has to be enhanced. Therefore, the safety information should be provided at a more appropriate time and should be easier to understand.

• The Journal of Industrial Distribution & Business
• /
• v.9 no.3
• /
• pp.57-68
• /
• 2018

Purpose - The purpose of this study is to classify that the quality factors for comparing the Visegrard Group with the Nordic Council have historical similarities against Germany and the Soviet Union. However, this is because in the integrated European market, the competitiveness possessed by the two groups of countries is invested in the priority order to grow. Research design, data, and methodology - The study was conducted on the research design, and the reason for trying to compare the competence of the automobile industry in the assessment of industrial capability is that the Visegrard Group focuses on automotive production and the Nordic Association focuses on the commercialization of the automobile(market). In this study, searching and quantifying indirect evidence was made through standards are more complementary in Europe since each country acts like the role of the European automotive industry for example, which is different from the realistic evaluation criteria, are more important than those of the United States(first in the world) or Germany(first in Europe). Results - The results of this study are as follows: In the global EV market U.S.(export: $ 2.62 billion /share: 36.7%), Germany($ 1.29 billion /18.1%), France($ 390 million /5.4%), United Kingdom($ 380 million /5.4%), and South Korea($ 320 million/ 4.4%). South Korea's share of the EV market is 4.4%, while TSI reaches at +0.9 which measures the comparative advantage of a specific commodity in the world trade market. There is great potential for evaluated as products processing in export competition. But, commercialization, standardization, and overall market expansion did not have a positive impact on global satisfaction. Conclusions - EVs put importance on various utilities. So this suggests that Korea's exports to the EU, including the Visegrard Group, should be more focused on marketability when illuminating with a sharing industrial system under the European Union. It is necessary to specialize in manufacturing and commercialization by country(region) to prepare sharing economy and blockchain in order to create a smart-sharing city linked on artificial intelligence, as the commercialization of electric vehicles, which will have a larger growth rate than that of manufacturing in the fourth revolutionary era.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.4 no.5
• /
• pp.1051-1066
• /
• 2000

According to the recent advances of digital encoding technologies and computing power, large amounts of multimedia informations such as image, graphic, audio and video are fully used in multimedia systems through Internet. By this, diverse retrieval mechanisms are required for users to search dedicated informations stored in multimedia systems, and especially it is preferred to use contents-based retrieval method rather than text-type keyword retrieval method. In this paper, we propose a new contents-based indexing and searching algorithm which aims to get both high efficiency and high retrieval performance. To achieve these objectives, firstly the proposed algorithm classifies images by a pre-processing process of edge extraction, range division, and multiple filtering, and secondly it searches the target images using spatial and textural characteristics of colors, which are extracted from the previous process, in a image. In addition, we describe the simulation results of search requests and retrieval outputs for several images of company's trade-mark using the proposed contents-based retrieval algorithm based on wavelet.