• 한국초전도ㆍ저온공학회논문지
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• 제19권2호
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• pp.29-32
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• 2017

The use of electronic devices such as mobile phones and tablet PCs has increased of late. However, the power which is supplied through wires has a limitation of the free use of devices and portability. Magnetic-resonance wireless power transfer (WPT) can achieve increased transfer distance and efficiency compared to the existing electromagnetic inductive coupling. A superconducting coil can be applied to increase the efficiency and distance of magnetic-resonance WPT. As superconducting coils have lower resistance than copper coils, they can increase the quality factor (Q-factor) and can overcome the limitations of magnetic-resonance WPT. In this study, copper coils were made from ordinary copper under the same condition as the superconducting coils for a comparison experiment. Superconducting coils use liquid nitrogen to keep the critical temperature. As there is a difference of medium between liquid nitrogen and air, liquid nitrogen was also used in the normal conductor coil to compare the experiment with under the same condition. It was confirmed that superconducting coils have a lower reflection-coefficient($S_{11}$) than the normal conductor coils.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.125-130
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• 2003

This paper provides approximate J estimates for off-centred, circumferential through-wall cracks in cylinders under bending. The proposed method is based on the reference stress approach, where the dependence of elastic and plastic influence functions of J on the cylinder/crack geometry, the off-centred angle and strain hardening is minimised through the use of a proper normalising load. Based on published limited FE results for off-centred, circumferential through-wall cracks under bending, such normalising load is found, based on which the reference stress based J estimates are proposed for more general cases, such as for a different cylinder geometry. Comparison of the estimated J with extensive FE J results shows overall good agreements for different crack/cylinder geometries which provides sufficient confidence in the use of the proposed method to fracture mechanics analyses of off-centred circumferential cracks. Furthermore, the proposed method is simple to use, giving significant merits in practice.

• 지역연구
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• 제14권2호
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• pp.1-33
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• 1998

Whereas previous researches on land policy after unification dealt with principally the problem of land confiscation under the communist reign, this research tried to propose a scheme of long-term land reform which was based on case studies on ex-socialist societies' experiences during their transformation, analysis on North Korea's institution related to land ownership and use. To reform North Korea's land ownership and use by the principle of market economy, North Korean should accumulate their commencing asset necessary for private ownership of land and housing. Therefore much focus should be put on the accumulation of the commencing asset at the early state of unification. On the extension of that line, the government of the Unified Korea should try to solve the problem of land confiscation by the communist party and land privatization in the region of North Korea. For the purpose, gradual land reform is more desirable than rapid one according to the case studies on ex-socialist societies. The government should avoid policies than can result in serious fiscal burden. Active participation of local government is highly recommendable in land tax and development. On the direction of land policy, this research proposed a four step long-term scheme of land reformation in North Korea. However, later researches should put more Korea. However, later researches should put more emphasis to the unification of land institution of North and South Korea which this research couldn't deal with sufficiently.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권5호
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• pp.968-988
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• 2010

Anonymous hierarchical identity based encryption (HIBE) is an extension of identity based encryption (IBE) that can use an arbitrary string like an e-mail address for a public key, and it additionally provide the anonymity of identity in ciphertexts. Using the anonymous HIBE schemes, it is possible to construct anonymous communication systems and public key encryption with keyword search. This paper presents an anonymous HIBE scheme with constant size ciphertexts under prime order symmetric bilinear groups, and shows that it is secure under the selective security model. Previous anonymous HIBE schemes were constructed to have linear size ciphertexts, to use composite order bilinear groups, or to use asymmetric bilinear groups that is a special type of bilinear groups. Our construction is the first efficient anonymous HIBE scheme that has constant size ciphertexts and that uses prime order symmetric bilinear groups. Compared to the previous scheme of composite order bilinear groups, ours is ten times faster. To achieve our construction, we first devise a novel cancelable random blinding technique. The random blinding property of our technique provides the anonymity of our construction, and the cancellation property of our technique enables decryption.

• Structural Engineering and Mechanics
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• 제39권4호
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• pp.499-520
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• 2011

The effectiveness of a technique for the repair of reinforced concrete members in combination with a technique for the repair of masonry walls of infilled frames, damaged due to cyclic loading, is experimentally investigated. Three single - story, one - bay, 1/3 - scale frame specimens are tested under cyclic horizontal loading, up to a drift level of 4%. One bare frame and two infilled frames with weak and strong infills, respectively, have been tasted. Specimens have spirals as shear reinforcement. The applied repair technique is mainly based on the use of thin epoxy resin infused under pressure into the crack system of the damaged RC joint bodies, the use of a polymer modified cement mortar with or without a fiberglass reinforcing mesh for the damaged infill masonry walls and the use of CFRP plates to the surfaces of the damaged structural RC members, as external reinforcement. Specimens after repair, were retested in the same way. Conclusions concerning the effectiveness of the applied repair technique, based on maximum cycles load, loading stiffness, and hysteretic energy absorption capabilities of the tested specimens, are drawn and commented upon.

• 한국사회복지학
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• 제42권
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• pp.340-371
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• 2000

The paradigm of care for persons with chronic mental illnesses has recently been shifted in Korea from institutionalization to community integration. Numerous changes in the service environment tend to target clients of mental health care organizations while a considerable proportion of people with similar clinical conditions have been institutionalized in various types of organizations whose auspices are other than mental health care. Under the current circumstances in which the subgroup of people, who tend to be socio-economically disadvantaged, has no viable alternative in the community to using such de facto mental health organizations, their chances of deinstitutionalization may decrease. This study thus aims at providing an increased understanding of the characteristics of the users and their service utilization, which in turn enables us to establish differentiated strategies within the current service context. In this study, a survey is conducted on the residential history of those with chronic mental illnesses both in the community and in institutions. Major characteristics of the users of de facto services are investigated along with the extent of their use of various existing mental and non-mental health services. Included is also an examination of the subjects' clinical and individual factors that may influence their use of de facto services. The study findings demonstrate relative disadvantages in deinstitutionalization in a subgroup of the population with chronic mental illnesses under the current mental health policies, and the author suggests intervening strategies specific to this population.

• 한국정보시스템학회지:정보시스템연구
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• 제27권4호
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• pp.203-227
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• 2018

Purpose The purpose of this study is to investigate which decision factors continue to use the service based on the online simple payment service. In this study, we will examine how to activate the service from the continuing factors through the dual-model theory consisting of personal dedication and constraint dedication which are frequently used in relation marketing. Design/methodology/approach In this study, we investigated the activation of online simple settlement service using factors affecting the preference of the simple payment service based on the dual-model of dedication-based mechanism and constraint-based mechanism. Findings This study confirmed that customer satisfaction and convenience under the dedication -based mechanism were found to be linked to the preference of the simple payment service. Switching cost under the constraint - based mechanism showed that the customer had no binding ability to continue using the service of the current provider. Likewise, preference was found to have a direct effect on the actual frequency of use of the simple payment service, the number of uses compared to the total number of online payments, and willingness to use more.

• International Journal of Contents
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• 제14권4호
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• pp.10-17
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• 2018

China media environment has drastically changed leading to the an inevitable change of public opinion ecology. Empirical studies have focused less on public opinion guidance, which forms an important component of the government officials' media literacy. This study applied quantitative method in the investigation of media literacy in China. Ideally, media literacy is measured from media cognition, media contact, media usage under the view of public opinion guidance. The findings reveal that the existing problem on 1) incorrect media cognition and public opinion guidance; 2) insufficient contact of personal social media 3) improper tendencies in the use of media to guide the public opinion, especially, on confidential information. Consequently, in order to improve media literacy in China government officials, enhancement of their basic knowledge on news diffusion and public opinion is necessary. Secondly, to effectively deal with "agenda settings", it is important for the government to consider the provision of valuable information and platforms to effectively spread information. So they need to learn how to personally and officially use social media platforms such as Weiboa and Wechat. This ensures they have maximized their potential to acquire valuable information and spread them on valuable platforms. Thirdly, government officials should be able to analyze and understand public opinion trends for official and personal use. Finally, they should understand the development of public opinion and the how online public opinion laws are formed and the target group.

• 유통과학연구
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• 제21권8호
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• pp.23-34
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• 2023

Purpose: To examine the economic effects of logistics under the influence of policies. Research design, data and methodology: This study is the first to use the panel data of 31 provinces and municipalities in China from 2012 to 2021, and use the OLS and DID models to evaluate whether the New Western Land-Sea Corridor (NWLSC) has promoted the economic development of the regions along the corridor. Results: The NWLSC has stimulated local economic growth by promoting the development of transportation, postal, and telecommunications industries along the corridor. Further, considering the locational differences of the regions along the NWLSC, we examined the differences in economic effects between regions along the Yangtze River and those not along the Yangtze River under the background of NWLSC implementation. We found that waterway and airway transport located along the NWLSC and in the Yangtze River Economic Belt (YREB) region can significantly promote economic growth. However, for regions located along the NWLSC but not in the YREB region, the impact of roadway, railway, and airway transport in these regions on economic growth is more significant. Conclusions: This study has important reference value on how to use logistics to promote the economic and cross-border commerce development of landlocked countries or regions.

• 무역상무연구
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• 제38권
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• pp.3-45
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• 2008

A motive and aim of enactment of UN Convention on the Use of Electronic Communication in Int'l Contracts is based on need to eliminate legal obstacles that might arise under existing int'l trade law instruments and promote int'l electronic commercial transaction. But when it is used with related articles, 14, 15, 16, 17 for offer under CISG, one of the most successful conventions which produces substantive law for the unification of int'l trade, questions of practical importance, for example possibilities of withdrawal, revocation, rejection of offer, the extent of its criteria arise from therewith. In conclusion, a effective electronic offer has to assure easily access and confirmation of trade terms besides criteria of offer under CISG. An offer can be withdrawal, if electronic message of withdrawal has entered the offeree's server before or at the same time when the offer has reached the offeree but agreement expressly or impliedly, between the parties about type, format, email address is a prerequisited. Implied consent could be presumed through prior conduct or trade usages between the parties under CISG articles 8, 9. The term "have reached" correspond to the time which is able to retrieve the electronic message of withdrawal. But without express or implied agreement between them about electronic communication of type, format, email address, an offer can be withdrawal before or at the same time when it has entered offeree's other e-mail address and confirmed by his retrieval. In case of the revocation, electronic message of the revocation is effective before the offeree's dispatching an acceptance. A prerequisite for the revocation by electronic communication is came as the above mentioned withdrawal except for concept of a time difference for reach. In case of a rejection of offer, when a rejection by electronic communication has entered the offeror's server, an offer is ended. But a prerequisite for the rejection by electronic message is same as the above mentioned withdrawal and revocation.