• Title/Summary/Keyword: Fair-exchange

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Interactive Oblivious Transfer Protocol using Bit Commitment and Digital Signature (Bit Commitment와 디지털 서명을 이용한 대화형 불확정 전송 프로토콜)

  • 김순곤;송유진;강창구;안동언;정성종
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.8A
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    • pp.1227-1237
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    • 1999
  • In this paper, we present an oblivious transfer protocol which is the protocol for the fair exchange of secrets. For this, we investigate the verifiable oblivious transfer protocol based on discrete logarithm broblem proposed by Lein Ham etc. And we propose a new obivious transfer protocol that has the additional functions on the existing method. This proposed method has the additional functions that enable to authenticate sender and to protect denial of what he/she has sent message to the other. To do this, we make use of bit commitment scheme and digital signature scheme based on RSA.

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Flatfish Vitellogenin Detection Using Optical Waveguide Lightmode Spectroscopy-based Immunosensor

  • Kim, Nam-Soo;Ryu, Hyung-Seok;Kim, Woo-Yeon
    • Journal of Microbiology and Biotechnology
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    • v.17 no.9
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    • pp.1445-1451
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    • 2007
  • A sensitive optical waveguide lightmode spectroscopy-based immunosensor was developed to detect vitellogenin in seawater flatfish (Paralichthys olivaceus). For this purpose, anion-exchange column chromatography with DE-52 resin was used to purify flatfish vitellogenin from flatfish serum containing vitellogenin that had been induced using an intraperitoneal $17{\beta}$-estradiol injection. The anti-flatfish vitellogenin antibody used as the biological component of the above immunosensor was prepared using the purified flatfish vitellogenin. The change in the incoupling angle according to the complexation between the flatfish vitellogenin and its antibody, immobilized over an optical grating coupler sensor chip, was measured to calculate the sensor response. The immunosensor was quite specific to flatfish vitellogenin binding, based on no sensor response in the case of bovine serum albumin immobilization. When plotted using double-logarithmic scales, the sensor responses increased linearly in flatfish vitellogenin concentrations of 0.00675-67.5 nM, with a detection limit of 0.0675 nM. The reusability during seven repetitive measurements was reasonably fair for the preliminary screening of flatfish vitellogenin.

Does the Pricing Mechanism Affect the IPO Flipping Activity in Pakistan?

  • ANWAR, Ayesha;MOHD-RASHID, Rasidah
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.1
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    • pp.237-246
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    • 2021
  • This paper explores the relationship between price mechanism and flipping activity of initial public offerings (IPOs) in Pakistan's emerging economy. This study uses a cross-sectional data set of 95 firms listed on Pakistan Stock Exchange from 2000 to 2019. This study employs the ordinary least square and quantile regression techniques to capture the relationship between price mechanism and flipping activity. The results show that book-built IPOs flip substantially less than fixed-price IPOs. This is consistent with the signaling theory assertion that roadshows are arranged by underwriters to capture investors' demand and set the offer prices of IPOs. If investors learn the fair values of quality IPOs, then the offer prices will be close to the intrinsic values, thus reducing flipping. The findings also provide conclusive evidence for understanding the usefulness of and the more relevant information regarding the pricing mechanism. In particular, it provides a better understanding of how companies actually use the pricing mechanism information in the flipping of IPO shares. The results of this study are also valuable to underwriters, and regulators, for instance, provides underwriters with the discretion to allocate the IPO shares and the SECP, in revising regulation on the disclosure of IPO pricing methods.

Outcome of Pars Plana Retinopexy with Perfluoro-n-octane-Silicone Oil Exchange for Rhegmatogenous Retinal Detachment in Dogs: 9 Eyes

  • Susanti, Lina;Kang, Seonmi;Park, Sangwan;Park, Eunjin;Park, Yoonji;Kim, Boyun;Jeong, Manbok;Seo, Kangmoon
    • Journal of Veterinary Clinics
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    • v.35 no.4
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    • pp.126-129
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    • 2018
  • This study was performed to describe the outcome of pars plana retinopexy with perfluoro-n-octane (PFO)-silicone oil (SiO) exchange in dogs with rhegmatogenous retinal detachment in Seoul National University Veterinary Medical Teaching Hospital (SNU VMTH) from 2014 to 2017. Nine eyes of 8 dogs were included in this study. Medical records including signalment, history, duration from onset of blindness to surgical intervention, pre-operative findings, duration from surgery to regaining vision, and post-operative complications were evaluated. No eyes were visual before surgery. Duration from onset of blindness to surgical intervention was 2-30 days (median 8 days); duration from surgery to regain vision was 1-14 days (median 6 days); follow-up time was 15-1088 days (median 69 days). Post-operative complications were divided as temporary vs permanent conditions. Temporary complications were corneal ulcer, uveitis, retinal haemorrhage, glaucoma, subconjunctival leakage of SiO, and vitreal haemorrhage. Permanent complications were anterior chamber migration of SiO, retinal degeneration, corneal degeneration, re-detachment, and cataract. Six of 9 eyes regained functional vision, five of which remained visual throughout the follow-up time while the other one lost vision after 3 months because of uveitic glaucoma. In conclusion, pars plana retinopexy with PFO-SiO exchange provided fair outcome in 66.7% cases described in this study.

The Outcome of the 6th ICAO Worldwide Air Transport Conference and Fair Competition Policy in International Air Transport (국제항공운송의 최근 동향과 항공운송의 공정경쟁정책 -ICAO 제6차 세계항공운송회의 결과를 중심으로-)

  • Shin, Dong-Chun
    • The Korean Journal of Air & Space Law and Policy
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    • v.28 no.1
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    • pp.97-114
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    • 2013
  • The 6th Worldwide Air Transport Conference was held in Montreal in March 2013 under the auspices of ICAO. This conference, which has been held every ten years, is dealing with virtually every issue of international air transport, and aiming at updating ICAO policy in order to ensure long-term growth of international civil aviation. Last conference which took place in 2003 focused on the liberalization of air transport, and the 6th conference shifted its focus from whether to push for liberalization, to how to implement it. The main agenda items for the 6th conference was liberalization, safeguards, ownership, fair competition, airports and air navigation facilities, charges, and ICAO policy. The liberalization, and in particular progressive liberalization has been a main theme over the past decades. In the process leading to liberalization, there needs to be the expansion of market access, easing regulation on ownership and control of airlines. Furthermore, the provision of enough infrastructure such as airport and air navigation facilities may be contributing factor to remove impediments to liberalization. However, out of concern as for undermining interests of consumer and the weak, when liberalization is proceeding in a sudden and radical manner, there should be safeguards so as to ensure market participation by developing countries, consumer protection, and economical and transparent decision on taxes and charges. Fair competition which differs from promoting competition in the market, is a policy in order to protect the weak players and consumers from monopoly and oligopoly. The Korean delegation submitted 3 WPs (WP/85, 86 and 87) and 1 IP, and presented WPs, at the conference, which were a lot compared with previous occasions. A paradigm shift was emphasized to expedite the process of liberalization at the 6th conference. The reality is that with many previous recommendations to stress the importance of liberalization, and to urge States to change their attitudes, the pace of the liberalization has been very slow and staggering. The liberalization of air transport will contribute to the growth of air transport and related industry, to create new employment, promoting tourism and regional development, and further to facilitating mutual understanding and exchange, which will also lead to making a barrier-free world. In this context, it is expected that the next conference will also evaluate the on-going process of liberalization.

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Analysis on the Problems of U.S.-Korea Air Services Agreement and Recommend Action for its Improvement- (한.미항공협정(韓.美航空協定)의 문제점(問題點)과 개선방향(改善方向))

  • Hong, Soon-Kil
    • The Korean Journal of Air & Space Law and Policy
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    • v.1
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    • pp.125-146
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    • 1989
  • This paper is examine the problems of U.S.-Korea Air Service Agreement and recommend some directions for its improvement under the rapidly changing circumstance and growing importance of Korean penisula. Since the provisional agreement of 1949, U.S. -Korea Air Service Agreement has consistently been favorable to U.S. side. Fair and equal opportunity is the principle and basis of the bilateral air agreement. Notwithstanding such principle, it is only the U.S. carriers who can freely enter into any market, under the discretion of business strategy, while Korean carrier can serve only three points including Honolulu. In an effort to recitify such serious imbalance, Korea continuousely requested additional rights and has given utmost efforts to accommodate requests made by U.S. carries without much success. When we review aviation market between Korea and U.S. under the present agreement, Korea is fully open to U.S. carries as they can connect from any or all points in the U.S. via any or all points in Korea and all points beyond Korea. Increased number of U.S. carriers are enjoying greater utilization of the opportunity accorded them. Four(4) U.S. carries now operate to Korea using thirteen(13) gateway points and about one hundred fifty(150) on-line points in the U.S. such imbalance can be well understood when we review the exchange of traffic rights between the U.S. and the Pacific rim countries. During the yeras following the 1978 agreement with Korea, the U.S. proceeded to sign liberal agreements with Thailand, Taiwan, Singapore and the Phillipines. In exchange, the U.S. granted the four Pacific rim countries substantially greater rights than were granted to Korea, although Korea was the first Asian nation to sign a pro-competitive aviation agreement which granted U.S. carriers unrestricted market access and pricing flexibility. Moreover, Korea ranks the 2nd trading and tourist partner to the U.S. among the Pacific rim countries (Japan is the largest partner to the U.S. in terms of both trade and tourist market). In this paper such problems in the Korea-U.S. Air Services Agreement are analyzed in terms of historical perspective, U.S. Aviation policy, imbalance status in detail cases, discrimination to Korea comparing to other Asian countries, and theoretical application. And further it discusses current aviation issues between Korea and U.S. such as the ratification of 1980 MOU and various doing business issues of U.S. carriers in Korea. Finally, this paper concludes the analysis and suggests some directions to improve and rectify the problems and imbalance of U.S.-Korea Air Services Agreement in question.

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Cyclic Codebook Scheme for Coordinated Scheduling and Beamforming (협력적 스케줄링 및 빔형성을 위한 순환적 코드북 기법)

  • Kim, Seong-Hyun;Lee, Sang-Hoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.11A
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    • pp.861-869
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    • 2011
  • In this paper, we propose coordinated scheduling and beamforming based on limited feedback to overcome the effects of inter-cell interference in multi-cell environment. The goal of this study is to improve a performance of cell-edge area significantly affected by the inter-cell interference and also to guarantee a performance of the entire system. Existing coordinated scheduling and beamforming based on the perfect channel state information generates an overhead for the channel state information feedback and exchange at the users and base stations, respectively. In this study, first we propose a novel codebook to obtain a null space of an interference channel efficiently which can be used to reduce the inter-cell interference. Using the proposed codebook, we propose coordinated scheduling and beamforming to improve the performance of cell-edge area and the entire system. Through the proportional fair scheduling, the performance of the proposed technique is shown as improvement of channel capacity for users located cell-edge area and entire system.

Reliable e-Commerce Model on P2P Environment (P2P 환경에서 신뢰성 있는 e-Commerce 모델)

  • Shin Jung-Hwa;Rhee Kyung-Hyune
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.8
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    • pp.1760-1768
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    • 2004
  • A P2P is a method that can share and exchange on digital resources through a direct connection on personnel without a central server. In this paper, we apply a P2P technology to a traditional electronic commerce method so that a seller and a customer can perform a commercial transaction through a direct communication. As such a result, we propose a new e-Commerce model on P2P environment to assure fairness in commercial transactions. To achieve our goal, we put an escrow server which is responsible for guarantee fair contents delivery and payment for the contents between a seller and a customer. When a customer buys content, he first obtains reputation values implicating reliability for the content and refers to these values to determine purchase. The proposed scheme, we can improve the reliability for the purchasing content and provide the fairness to both a seller and a customer simultaneously.

Various Issues on International Guarantee (국제적(國際的) 보증(保證)의 제문제(諸問題))

  • Suk, Kwang-Hyun
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.17
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    • pp.7-35
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    • 2002
  • In many international financing transactions Korean companies are required to issue a guarantee. Thus far, however, legal issues on international guarantees have not been fully discussed in Korea. This is partly because most of the international guarantees are governed by a foreign law such as English law or the laws of the State of New York. In this articles the author examines major concepts or terms and conditions of a typical international guarantee, e.g., language on consideration, primary obligor, joint and several guarantee, unconditional and irrevocable guarantee, continuing guarantee, right of subrogation, representations and warranties, covenant or undertaking, currency indemnity, assignment, participation, governing law and jurisdiction clause, etc. For reference, standard forms of a guarantee and a standby letter of credit are attached to the article. In examining the terms and conditions, the author compares them with similar or equivalent concepts under Korean law. The author further discusses some Korean law issues that may arise under international guarantees governed by a foreign law. These issues include the application of the ultra vires doctrine under Article 34 of the Civil Code of Korea, the validity of an international guarantee which a Korean company has issued in violation of the guarantee ceiling set under Article 10 of the Law on Monopoly Regulation and Fair Trade of Korea and the validity of an international guarantee which a Korean party has issued in violation of the Foreign Exchange Transaction Law. In addition, the author discusses some issues under a so-called independent guarantee and a standby letter of credit. In this regard, reference is made to the Uniform Rules for Demand Guarantee (URDG), International Standby Practices (ISP98) and the Convention on Independent Guarantees and Stand-by Letters of Credit adopted by the United Nations in 1995. Finally, the author examines major terms and conditions of typical comfort letters and discusses some legal issues, such as the binding force of the comfort letter. In dealing with the issues the author underscores that to the extent the issues are not properly dealt with by an international norm such as Uniform Customs and Practice for Documentary Credits or ISP 98, the issues must be analyzed by reference to the governing law of the relevant instrument.

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A Study on Necessity of System for mediating transactions of a mobile gift certificate (모바일 상품권 거래 중개 시스템의 필요성에 관한 연구)

  • Bae, Yu-Mi;Jung, Sung-Jae;Lee, Kwang-Yong;Jang, Rae-Young;Lee, Jae-Ung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.05a
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    • pp.185-188
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    • 2016
  • The percentage share of mobile gift card certificate in the gift card market has increased significantly each year. But from a consumer perspective mobile gift card certificate has several problems. Specifying unfair terms in Fair Trade Commission has improved slightly, but the problem is not replaced with the equivalent authority that issued the vouchers can not be solved. The exchange between users the most realistic way to solve this problem is to create an environment as possible. In conclusion, The deal will be possible to build a mobile gift card certificate brokerage trading in a convenient and reliable P2P-based. If the System for mediating transactions of a mobile gift certificate has created a healthy retail environment, such as the expansion of the voucher market, reduce social costs may be creating.

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