• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.247-250
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• 2005

Recently, a concept of bid-rigging is issued in electronic auction. To prevent this attack, Abe-Suzuki proposed firstly receipt-free scheme based on bidding-booth. Chen-Lee-Kim pointed out that Abe-Suzuki's scheme only provides receipt-freeness for losing bidders. Also, they introduced a new receipt-free sealed bid auction scheme using the homomorphic encryption technique. The main participants of their scheme are Auctioneer, Auction Issuer, Bidder and Seller. Bid-rigging can happen by a seller in their scheme. We propose receipt-free sealed-bid auction scheme using a universal re-encryption mixnet. For our receipt-free sealed-bid auction, we use Pseudo ID of a bidder and universal re-encryption technique of Golle et al. Also, our scheme satisfies privacy, correctness, public verifiability, non-reputation, and receipt-freeness.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.4173-4176
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• 2012

Background: Adolescent tobacco use is a major public health problem. However, there is little information about the impact of tobacco advertising and availability near schools on adolescent tobacco use in India. Methods: The various tobacco products and brands available in outlets within 100 meters of two high schools in an Indian town were identified. A stratified random sample of 172 participants from these two schools completed a questionnaire on tobacco use and socioeconomic status. Results: Eighteen outlets selling tobacco products were identified. In the two schools the current use of smoked and smokeless tobacco was 9.1% and 17.4% respectively. School location and low socio-economic status of adolescents were associated with tobacco awareness of advertisements (p=0.001) and the receipt of a free sample (p= 0.032). Advertisements on billboards, posters and the receipt of a free tobacco sample were significant factors (p=0.031, p=0.016, p=0.017 respectively) in current tobacco use. Conclusion: In this study a significant proportion of adolescents used tobacco. Tobacco-promotion activities (advertising, the receipt of a free sample), school location and economic status were found to be associated with adolescent tobacco initiation. The local environment should be included in the prevention of adolescent tobacco initiation.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.2
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• pp.49-61
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• 2003

Electronic voting schemes must provide universal verifiability and receipt-freeness, as well as basic properties such as privacy, eligibility, to make the election fair and transparent. But it is difficult to provide both universal verifiability and receipt-freeness because they are mutually contradictory in their objective. To date, most electronic voting schemes provide only one of these properties and those few that provide both properties are not practical due to heavy computational load. In this paper, we present an efficient electronic voting scheme that provides both properties. The proposed scheme uses a trusted third party called HR(Honest Randomizer) and requires only one-way untappable channels from HRs to voters. Among the schemes that assume only one-way untappable channel this scheme requires the least amount of computation. Among the schemes that provide both properties, this scheme uses the weakest physical assumption. We also discuss the security of the system and compare our scheme with other related schemes.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2002.11a
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• pp.95-98
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• 2002

공정하고 투명한 선거를 이루기 위해서는 비밀성(privacy), 선거권(eligibiligy) 등과 더불어 전체검증(universally verifiability)과 매표방지(receipt-freeness) 속성이 반드시 제공되어야 한다. 그러나 전체검증은 누구나 투표내용을 확인할 수 있는 방법을 제공하는 것이고 매표방지는 투표내용과 투표자를 연결할 수 있는 방법을 차단하는 것으로 두가지 특성은 상호표리적 관계에 있어서 두가지 특성을 동시에 만족시키기가 어렵다. 이 논문에서는 신뢰할 수 있는 제3자인 정직한 랜덤마이저(Honest Randomizer, HR)와 최소한의 물리적 가정인 HR에서 유권자로 가는 도청 불가능한 채널(untappable channel)을 이용하여 전체검증과 매표방지를 제공하는 효율적인 전자선거 기법을 제안한다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.12a
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• pp.605-610
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• 2003

선거를 전자적으로 구성하기 위해서는 비밀성(privacy), 선거권(eligibility) 등과 함께 전체검증(universal verifiability)과 매표방지(receipt-freeness) 속성을 반드시 제공해야 한다. 지금까지 제안된 전자선거 기법은 매표방지와 전체검증을 제공하기 위해 도청 불가능한 채널이라는 물리적인 가정 하에 이루어지거나 하드웨어 장치를 이용하더라도 장치에 대한 신뢰가 가정되었다. 본 논문에서는 믹스 서버나 랜덤마이저의 역할을 스마트카드와 같은 안전한 하드웨어 장치가 하므로 물리적 가정 없이 효율적으로 구현한다. 제안한 시스템은 표를 섞는 과정에서 permutation matrix를 사용하여 증명하므로 증명의 회수가 적고 간단하여 효율적이다. 또한, 지금까지 제안된 대부분의 선거 기법은 ElGamal 암호시스템의 준동형 특성을 이용하여 모든 표를 결합한 다음 해독하여 집계를 계산하는데 이는 이산대수 문제를 효율적으로 해결할 수 있어야 가능했다. 이 논문에서는 ElGamal 암호시스템과 다차잉여 기반 암호알고리즘인 Naccacne 암호알고리즘을 결합하여 표를 인코딩 함으로써 유권자의 수가 많은 선거에 대해서도 다항 시간 내에 집계가 가능하다.

• The KIPS Transactions:PartC
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• v.8C no.3
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• pp.263-270
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• 2001

정보사회를 거치면서 네트워크의 발전과 관련한 많은 응용 분야들이 연구되고 있는데, 그 중에서도 암호학을 이용한 전자 투표의 비중이 증대되고 있다. 이러한 전자 투표는 그 중요성에도 불구하고 아직까지 취약한 점이 많이 산재해 있다. 특히, 전자 투표를 총괄하는 선거 관리위원회가 부정을 저지를 경우 투표 자체의 신뢰성은 무너지게 되며, 투표권의 매매가 성립할 경우에는 전자 투표에 있어 치명적인 악영향을 미치게 될 것이다. 딸서 몬 논문은 기존의 투표를 전자 투표로 적용시키는 과정에서 어떠한 요소들이 필요한지 확인해 보고 선거관리 위원회의 부정 방지 및 매매 방지를 위한 요구 조건을 살펴볼 것이다. 또한 매매방지를 위해 네트워크 상에서 익명성을 제공하는 안전한 선택 기법인 “Magic Sticker” 기법을 사용하여, 투표자의 투표 내용이 공개되더라도 투표 결과를 안전하게 보호할 수 있는 전자 투표 시스템을 제안한다.

• Journal of Convergence Society for SMB
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• v.5 no.3
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• pp.21-26
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• 2015

As mobile contents grow up, In App Billing is brisk at applications including mobile contents. But some of users don't pay and use charged content for free to use cheating payment module or hacking through applications. Call this bypass payment. Applications, helping bypass, are Freedom, IAP Cracker, and DNS server suggested by the hacker named Borodin. In case of mobile game, Despite sell a lot of charged content but income is different revenue in sales log with real profits. Because of users using bypass payment application. Management plan to bypass payment are checking OrderID, encrypting public key and verifying receipt.

• Journal of the Korean Home Economics Association
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• v.46 no.1
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• pp.87-101
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• 2008

Using the 1999 National Survey of America's Families(NSAF), this study investigated the factors that affect child care expenses and examined financial and social support of single mother families in the U. S. In this study, 4,676 single mother families with children aged twelve and under are included for the analytical sample. About half of all single mother families with children under age 12 had some amount of child care expenses in 1999. Monthly child care expenses for those who had child care expenses was an average of $255 and it accounted for about 15 percent of their family earnings. The profile of financial and social support showed that about one-quarter of single mothers received financial support for child care, one-fifth received free child care by relatives and about 40 percent received child support payments from nonresident fathers. Tobit analysis results showed that the significant factors that affected child care expenses were mother's age, marital status, educational level, employment status, the numbers of children aged 0-5, family income, the receipt of public assistance and financial support for child care.

• Research in Community and Public Health Nursing
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• v.7 no.1
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• pp.69-79
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• 1996

To investigate the factors related with the compliance and the treatment of the patients with pulmonary tuberculosis in urban and suburb area, we followed up all the 755 registered patients(at urban Public Health Office 544, at suburb 210) as follow from January 1,1992 to December 31, 1993. We describe the general characteristics and the characteristics related with the disease of the patients according to the area as follow. 150 patients(27.5%) were at their age of 20 to 29 years in the urban area, whereas 45 patients (21.4%) were 60 to 69 years and another 45 patients(21.4%) were 70 to 79 years in the suburb area. According to the first chest X -ray examination, 54.5% of all cases were proved to be mild in the urban area. But in the suburb area, moderate cases (44.3%) were more than mild cases(p<0.01). Follow-up X-ray's were performed more properly(p<0.05) in the urban area(94.3%) than in the suburb area(90.0%). Most cases were found in the chest X -ray examination performed by Public Health Office (p<0.01) : payable chest X-ray in the urban area (56.7%) and free chest X-ray in the suburb area(35.2%). More patients were cured in the urban area(90.8%) than in the suburb area(87.1%). The presence of supporting family member were significantly higher(p<0.05) in the urban area(79.1%) than in the suburb area(88.1%). In the analysis of the treatment efficacy, more cure ate were found in the patients cytologically confirmed to be culture (+). In the urban area, 201 culture (+) patients (93.5%) 294 culture (-) patients (89.1%) were cured. In the suburb area, 99 culture (+) patients(91.7%) and 84 culture (-) patients(82.4%) were cured. Age, the presence of supporting family member, and the socioeconomic status of the patient had significant association with the prescription compliance related with the general characteristics of the patients. Whereas, X-ray finding and AFB culture finding were the significant factors associated with the prescription compliance related with pulmonary tuberculosis (p<0.05). The cumulative compliance in the survival analysis was 92.5% in the urban area and 88.1% in suburb area, at sixth month of follow-up. Failure rate for regular drug receipt was highest at second month in the urban area(3.75%) and at fourth month in the suburb area(4.15%). In logistic regression of the factors related with the tratment result, first X-ray examination and prescription compliance were significantly associated in the urban area(p<0.05). However, there is no factor significantly associated with the treatment result in the suburb area. It could be explained by too small size of the sample. In logistic regression of the factors related with the prescription compliance, first chest X-ray, sputum culture outcome and the presence of supporting family member were significant variables in the urban area(p<0.05). Most patients with family member were proved to be compliant with the prescription. This shows that it is important for the patients with long-lasting ilnesses to have supporting family member. Therefore, to improve prescription compliance we should strengthen the health education before the initiation of treatment and take special interest in the patients without supporting family member.

• Journal of Venture Innovation
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• v.5 no.3
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• pp.57-70
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• 2022

In modern industrial capitalism, the relationship between the provision of work and the receipt of wages has become an important principle governing society. According to the labor contract, the wages provided by entrusting the right to dispose of one's labor to the employer are directly compensated, and human life should be guaranteed and reproduced with proper rest. The establishment of labor relations under free contracts represents a problem in protecting workers, and accordingly, the maximum of working hours is set as a minimum right for workers, and the standard for minimum rest is set and assigned. The reduction of working hours is very important in terms of the quality of life of workers, but it is also an important issue in efficient corporate activities. As of 2020, Korea has 1,908 hours of annual working hours, the third lowest among OECD 37 countries in the happiness index surveyed by the Sustainable Development Solution Network(SDSN), an agency under the United Nations. Accordingly, the necessity of reducing working hours has been recognized, and the maximum working hours per week has been limited to 52 hours since 2018. In this situation, various working hours are legally excluded as a way to maintain the company's value-added creation and meet the diverse needs of workers, and Korea's Labor Standards Act restricts flexible working hours within three months, flexible working hours exceeding three months, selective working hours, and extended working hours. However, in the discussion on the application of the revised flexible working hours system in 2021 and the expansion of the settlement unit period recently discussed, there is a problem with the flexible working hours system, which needs to be improved. Therefore, this paper aims to examine the problems of the flexible working hours system and improvement measures. The flexible working hours system is a system that does not violate working hours even if the legal working hours are exceeded on a specific day or week according to a predetermined standard, and does not have to pay additional wages for excessive overtime work. It is mainly useful as a form of shift work in manufacturing, sales service, continuous business or electricity, gas, water, and transportation for long-term operations. It is also used as a way to shorten working hours, such as expanding holidays through short working days. However, if the settlement unit period is expanded, it is disadvantageous to workers as the additional wages that workers can receive will not be received. Therefore, First, in order to expand the settlement unit period currently under discussion, additional wages should be paid for the period expanded from the current standard. Second, it is necessary to improve the application of the flexible working hours system to individual workers to have sufficient consultation with individual workers in a written agreement with the worker representative, Third, clarify the allowable time for extended work during the settlement unit period, and Fourth, limit the daily working hours or apply to continuous rest. In addition, since the written agreement of the worker representative is an important issue in the application of the flexible working hours system, it is necessary to secure the representation of the worker representative.