• Journal of the Korea Society of Computer and Information
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• 제27권11호
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• pp.1-11
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• 2022

In this paper, we propose an NFT(Non-Fungible Token)-based access control method for safely sharing data between users in blockchain environment. Since all data stored in the blockchain can be accessed by anyone due to the nature of the technology, it is necessary to control access except for authorized users when sharing sensitive data. For that, we generate each data as NFT and controls access to the data through the smart contract. In addition, in order to overcome the limitations of single ownership of the existing NFT, we separated the NFT into ownership and use rights, so that data can be safely shared between users. Ownership is represented as an original NFT, use rights is represented as a copied NFT, and all data generated as NFT is encrypted and uploaded, so data can be shared only through the smart contract with access control. To verify this approach, we set up a hypothetical scenario called Building Information Modeling (BIM) data trade, and deployed a smart contract that satisfies 32 function call scenarios that require access control. Also, we evaluated the stability in consideration of the possibility of decryption through brute-force attack. Through our approach, we confirmed that the data can be safely shared between users in blockchain environment.

• Journal of the East Asian Society of Dietary Life
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• 제17권4호
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• pp.589-596
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• 2007

The level of hygiene practices varies depending on a variety of factors. The purpose of this study was to evaluate the level of hygiene practices performed in the contract foodservice establishments based on several variables, and to also determine the possible effects of each variable on the performance level of hygiene practices. We surveyed 215 contract foodservice establishments, excluding school facilities, managed by a large-scale contract foodservice company. The survey used a formulated sanitary checklist to evaluate the level of hygiene practices performed in the foodservice establishments. The sanitary checklist consisted of a total of 52 items in all 6 categories including personal sanitation and process control. The collected data underwent a series of analyses such as frequency analysis, ANOVA, and correspondence analysis of means using SPSS. from the results, we found significant differences among groups in categories such as the existence of a person in charge and types of business. A higher foodstuff cost had a tendency to correlate with a higher performance level for sanitary maintenance, but there was no significance on a statistical level.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• 제20권
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• pp.241-265
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• 2003

The purpose of this paper is to examine the customs clearance impediment and trade parties breaches of international sales contract by the impediment. Customs clearance impediment arises when (a)clearance is not permitted, (b) importation goods are confiscated, (c)clearance delay without expectation, and (d) additional excessive trade cost caused in the process of clearance. This kind of clearance impediment may cause the breach of international sales contract. And it depends on its contents of contract and causal sequence i.e. cause and effect respectively in determining who is liable for it. If one party exemptions by Article 79 CISG, next three elements must be proved. (a)The failure was due to an impediment beyond his control; (b)the impediment was reasonably unforeseeable at the time of the conclusion of the contract, and (c)the impediment was reasonably impossible to overcome. But the customs clearance impediment is not easy to prove these three elements, the party who is responsible the customs clearance may not be exemptions by Article 79 CISG. And, according to review, it is concluded that the buyer, rather than seller, is liable for the damage which is caused in the process of clearance. It is also confirmed that the seller is sometimes liable for depending on clauses of contracts i.e. quality conditions.

• Nutritional Sciences
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• 제5권2호
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• pp.103-110
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• 2002

In Korea, the school foodservice program has been expanding rapidly in recent years, partly as a result of increased government support. With the growth in the number of schools offering foodservice programs, food safety and sanitation concerns have been increasing. To assist with program improvement, a situation analysis was carried out, with the focus on equipment and sanitary management of school foodservice programs under flour different management systems. A questionnaire was mailed to the foodservice directors of 234 randomly selected schools chi[h included elementary, middle and high schools at the national level. Among them, one hundred and sixty-five responses reasonably completed were used for the analysis. This study classified each school's foodservice management into one of four types : independent-conventional, independent-commissary, contract-conventional, and contract-delivery. The results show that the monitoring of employees' health and personal hygiene, and employees' sanitary education was well conducted, but that the sanitary education of the voluntary parent workers was largely ignored. Eighty-six percent of the schools had their drinking water tested for sanitation, and the results showed that more effort is needed in careful management of drinking water in order to prevent foodborne illnesses and bacillary dysentery. In general, contract management showed lower scores in foodservice equipment and their efficiency, compared with independent management. A relatively high number of schools on the contract-delivery management system employed nurses and leachers instead of dietitians and foodservice directors. The adoption of the HACCP (Hazard Analysis Critical Control Point) system was lowest in contract-conventional and contract-delivery management systems, and highest in elementary schools using the independent-conventional system.

• Journal of the Economic Geographical Society of Korea
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• 제25권4호
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• pp.451-468
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• 2022

Leading enterprises in contract farming are in control of agricultural production and influence the structure of the agricultural system in contract areas. This study focuses on the contract farming of potatoes for manufacturing chips, which uses a high proportion of domestic raw materials, and identifies the characteristics of contract farming between confectionery company 𐩒 and potato farms in Haean-myeon, Yanggu-gun, Gangwon-do. This study also analyzes the impact of contract farming on local agriculture from the perspective of the industrialization of agriculture. The results of this study demonstrated that contracting companies ensured the quality of potatoes and smooth agricultural operations by first preferentially selecting farmhouses with land that is easy to work with and then supplying the necessary agricultural machinery to promote the intensification of their work. In addition, contracting companies influenced the centralization of the agriculture sector by selecting farmhouses capable of contracting over a certain scale and guaranteeing them sales channels and the specialization of potato farming in contract areas, mainly through the supply of processing varieties and the spread of cultivation technology. The results confirmed that these three dimensions of contract farming promoted the industrialization of local agriculture.

• KIPS Transactions on Computer and Communication Systems
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• 제11권5호
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• pp.147-156
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• 2022

Industrial control systems that manage and maintain various industries were mainly operated in closed environment without external connection, but with the recent development of the Internet and the introduction of ICT technology, the access to the industrial control system of external or attackers has become easier. Such incorrect approaches or attacks can undermine the availability, a major attribute of the industrial control system, and violation of availability can cause great damage. In this paper, when issuing commands in an industrial control system, a verification group is formed using a random list to verify and execute commands, and a trust score technique is introduced that applies feedback to the verification group that conducted verification using the command execution result. This technique can reduce overhead generated by random generation in the process of requesting command verification, give flexibility to the verification process, and ensure system availability. For the performance analysis of the system, we measured the time and gas usage when deploying a smart contract, gas usage when verifying a command. As a result, we confirmed that although the proposed system generates a random list compared to the legacy system, there was little difference in the time when it took to deploy smart contract and that the gas used to deploy smart contract increased by about 1.4 times in the process of generating a random list. However, the proposed system does not perform random operations even though the operation of command verification and confidence score technique is performed together during the command verification process, thus it uses about 9% less gas per verification, which ensures availability in the verification process.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• 제19권1호
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• pp.49-54
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• 2013

Background: The purposed of this study is to examine the static and dynamic plantar foot pressure in chronic low back pain patients and normal adults. Methods: The subjects were divided into a group of 30 patients with chronic low back pain and a control group of 30 healthy persons. While static posture and dynamic posture at comfortable walking speeds, the low back pain group and the control group measured their plantar foot pressure and the trajectory of their center of pressure (COP) using the Matscan(R) system. Independent t-tests were measured to compare differences in plantar foot pressure characteristics between the left side and right side of the low back pain group and the control group. Results: In the comparison of differences in plantar foot pressure characteristics between the left side and right side of the low back pain group and the control group, the anteroposterior (AP) displacement of COP showed significant differences (p<.05). Although the low back pain group and the control group did not show any significant differences in leg length, weight distribution, mediolateral (ML) displacement of COP, static contract area, dynamic contract areas (p>.05), increases in the contract area values were shown in the hind foot in general. Conclusion: In this study, it was shown that patients with chronic low back pain were walking with short AP displacement of the COP as a compensatory action to avoid pain.

• The Journal of the Korea Contents Association
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• 제3권4호
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• pp.38-47
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• 2003

Distributed problem solving is the cooperative solution of problem by a decentralized and loosely couped collection of knowledge-sources (KS's), located in a number of distinct processor nodes. The contract net protocol has been developed to specify problem-solving communication and control for nodes in a distributed problem solver. Task distribution is affected by a negotiation process, a discussion carried on between nodes with tasks to be executed and nodes that may be able to execute tasks In this paper, we present the coordination method among distributed intrusion detection system and firewall by the contract net protocol. The method enhances the intrusion detection performance and provides the communication methods. To mode IDS and firewall, security models hue been hierarchically constructed based on the DEVS (Discrete Event system Specification) formalism. Each ID agent cooperates through the contract net protocol for detecting intrusions. The IDS which detects the intrusion informs to firewall, so the harmful network traffic is blocked. If an agent detects infusions, the agent transfers attacker's information to a firewall. Using this mechanism attacker's packets detected by In can be prevented from damaging the network.

• Culinary science and hospitality research
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• 제12권4호
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• pp.46-62
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• 2006

This study researched unequal trades and analyzed the difference of legal relation control between the franchisor and the franchisee in foodservice industry. The purpose of this study was the preparatory process for basic data to establish a statute law for the franchisee in foodservice industry. We made up a questionnaire for 53 franchisees in March 2004 and analysed spss 10.0. This result was as follows. First, the special office was needed for publicity activities of law related franchise and the investigation of a right in the written contract for a franchisee. Second, there should be the conformation and objective criteria of monopolistic goodwill in legal proceedings. Third, the larger the scale of franchisees was, the less efficiently the conflicts between franchisors and franchisees were controlled.

• International Journal of Internet, Broadcasting and Communication
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• 제13권4호
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• pp.1-10
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• 2021

The purpose of the study is to contribute to the positive development of blockchain technology by providing data to examine security vulnerabilities and threats to blockchain-based services and review countermeasures. The findings of this study are as follows. Threats to the security of blockchain-based services can be classified into application security threats, smart contract security threats, and network (P2P) security threats. First, application security threats include wallet theft (e-wallet stealing), double spending (double payment attack), and cryptojacking (mining malware infection). Second, smart contract security threats are divided into reentrancy attacks, replay attacks, and balance increasing attacks. Third, network (P2P) security threats are divided into the 51% control attack, Sybil attack, balance attack, eclipse attack (spread false information attack), selfish mining (selfish mining monopoly), block withholding attack, DDoS attack (distributed service denial attack) and DNS/BGP hijacks. Through this study, it is possible to discuss the future plans of the blockchain technology-based ecosystem through understanding the functional characteristics of transparency or some privacy that can be obtained within the blockchain. It also supports effective coping with various security threats.