• Title/Summary/Keyword: Systems engineering

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Associations of Transport Accessibility with Restaurants' Survival in Gwangju Metropolitan Area (광주광역시 음식점 개폐업과 교통접근성의 상관관계 분석)

  • Song, Yena;Jang, Hanwool;Lee, Keumsook
    • Journal of the Economic Geographical Society of Korea
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    • v.23 no.4
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    • pp.425-437
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    • 2020
  • In Korea, the proportion of self-employed and unpaid family workers is relatively higher than other OECD countries and the operation periods of their businesses are generally shorter than others. This indicates frequent startups and closures and thus unstable employment status and income, which inevitably generates huge social costs. Restaurants are a representative business that self-employed workers easily enter and their 5-year survival rate is found to be lower than 20%. This is shorter survival period than other business sectors. This study aims to examine the associations of transport accessibility with restaurants' survival in Gwangju metropolitan area. Convenient location has been known to be a crucial factor for sales improvements and longer operation and such location is closely linked with good transport accessibility. Results from survival analysis on empirical data show that better access to road networks is significantly associated with longer survival of restaurants though subway accessibility is not. This can be explained by low modal share of subway in the study area and at the same time, requires further case studies where more developed and matured subway systems are in operation.

An Comparative Study on the Method of Determining Allowable Horizontal Bearing Capacity of Piles (말뚝의 허용횡방향지지력 결정법의 비교연구)

  • Lee, Seung-Hyun;Han, Jin-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.6
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    • pp.267-274
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    • 2021
  • Among several methods for determining the allowable lateral resistances of piles, the subgrade reaction method and ultimate lateral resistance method are generally used. To determine the effects of the soil conditions, pile head restraint conditions, and pile lengths on determining the allowable lateral resistances of piles, computations of the allowable lateral resistances of piles using the two methods were executed, and the computation results were compared. For piles in soft cohesive soil, the pile design is governed by the allowable lateral resistance of a pile from subgrade soil reaction method regardless of the pile head restraints conditions and pile lengths. The allowable lateral resistance of a pile from the ultimate lateral resistance governs the design as the undrained shear strength increases. Except for the case of a short pile, which is installed in loose granular soil, the allowable lateral resistance of a pile from ultimate lateral resistance governs the design of laterally loaded piles. According to this study, computation of the ultimate lateral resistance of a pile is needed, even though some opinions suggest that the design of a laterally loaded pile is satisfied only by the subgrade reaction method. The pile width barely influences the coefficient of horizontal subgrade reaction. Realistically, the effect of the pile width can be disregarded in the condition of common pile widths of 20~90cm.

Analysis of Future Demand and Utilization of the Urban Meteorological Data for the Smart City (스마트시티를 위한 도시기상자료의 미래수요 및 활용가치 분석)

  • Kim, Seong-Gon;Kim, Seung Hee;Lim, Chul-Hee;Na, Seong-Kyun;Park, Sang Seo;Kim, Jaemin;Lee, Yun Gon
    • Atmosphere
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    • v.31 no.2
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    • pp.241-249
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    • 2021
  • A smart city utilizes data collected from various sensors through the internet of things (IoT) and improves city operations across the urban area. Recently substantial research is underway to examine all aspects of data that requires for the smart city operation. Atmospheric data are an essential component for successful smart city implementation, including Urban Air Mobility (UAM), infrastructure planning, safety and convenience, and traffic management. Unfortunately, the current level of conventional atmospheric data does not meet the needs of the new city concept. New and innovative approaches to developing high spatiotemporal resolution of observational and modeling data, resolving the complex urban structure, are expected to support the future needs. The geographic information system (GIS) integrates the atmospheric data with the urban structure and offers information system enhancement. In this study we proposed the necessity and applicability of the high resolution urban meteorological dataset based on heavy fog cases in the smart city region (e.g., Sejong and Pusan) in Korea.

A Study on Valuation of Defense Technology -Focusing on Overseas Technology Transfer- (국방 기술가치평가에 관한 연구 -국외 기술이전을 중심으로-)

  • Goh, Hwa-Jin;Jeon, Jeong-hwan;Kim, Joon-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.6
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    • pp.147-154
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    • 2021
  • Recently, it has been observed that as the level of Science and Technology in Korea is improving, the demand for technology transfer from overseas buyers is also increasing. A technical value is an important factor for the technology transfer process and the valuation of technology should be performed reasonably. Specifically, a non-economical value has to be examined thoroughly when conducting the valuation for a technology that depends on public values. Since public technology has public benefit as its purpose when compared to technology from the private sector, its discount rate should be appropriately assessed and reflected in its valuation process. In this context, this study presents the methodology of valuation of public technology particularly relating to the transfer of technology from the national defense industries. To be specific, both an application method of the discount rate according to the characteristics and the purpose of the target technology and a qualitative and quantitative evaluation method to reflect the public values are presented. The proposed method for the valuation of defense technology could be used practically both in strengthening bargaining capability based on the reasonably derived technical values for transfer of national defense technology abroad and in the compilation of budgets for technology development in the future.

Effect of Characterisitcs of Service Quality on Continuance Usage Intention of Digital Healthcare Service Using Mediating Factors of User Expectation and User Utility (디지털헬스케어서비스에서 서비스품질 속성이 지속사용의도에 미치는 효과연구: 사용자기대와 사용자효용 매개요인을 중심으로)

  • Jeon, Eun-Seon;Kim, Chul Soo
    • The Journal of Society for e-Business Studies
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    • v.26 no.2
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    • pp.1-17
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    • 2021
  • This paper elucidates the effect of characteristics of service quality on continuance usage intention of digital healthcare service using mediating factors of user expectation and user utility. First, we classified independent factors into three types such as service system characteristics, user characteristics, and healthcare service characteristics from the previous studies, and investigated the effect of three independent factors on continuance usage intention of digital healthcare service. Second, we analyzed the impact of two mediating factors, user expectation and user utility, on the continuance usage intention. We developed a research model that includes three types of independent factors, mediated factors of user expectation and user utility, and a dependent factor of continuance usage intention. We surveyed a total of 357 samples from digital healthcare service users and analyzed the research model. The research results significantly show that Characteristics of Users is essential factor impacting a dependent factor of Continuance Usage Intention. The results indicate the followings: (1) Characteristics of Users including the variables of Innovation impacts User Expectation, and User Expectation affects Users Utility, and Users Utility also affects Continuance Usage Intention. (2) Characteristics of Service Systems including the variables of Functionality, Compatibility, and Convenience and Characteristics of users of Innovation variable impact the mediating factor of User Expectation, and User Expectation also affects the factor of Continuance Usage Intention. (3) Characteristics of Healthcare Services including the variables of Reliability, Ease of Operation, Safety, and Accuracy impact User Utility, and User Utility also affects Continuance Usage Intention.

Research trends and views for insect-proof food packaging technologies (해충유입 방지를 위한 방충포장기법의 연구 동향 및 전망)

  • Chang, Yoonjee;Na, Ja-hyun;Han, Jaejoon
    • Food Science and Industry
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    • v.50 no.2
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    • pp.2-11
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    • 2017
  • Packaging is the last defensive barrier that protects food products from insect infestation during storage. However, though packaging films are hermetically sealed, insects can still be attracted by strong olfactory cues and penetrate through packaging materials, resulting in contamination. Insect contamination may cause consumers to be repulsed by contaminated food products. Especially, it is well known that stored-product insects cause critical problems in the cereal industry by inducing quantitative and qualitative damages to the grain products. The contaminations are caused by insects' metabolic byproducts and body parts, consequentially caused customer repulsion. Therefore, it is necessary to repel and control insects. However, management systems for storage insects in food industry have been inadequate for many years. Synthetic pesticides has been widely used, but pesticides may accumulate in foods, causing acute and chronic symptoms in consumers. For this reason, there is a growing need for the development of natural insecticides that can replace synthetic pesticides. Thus, various reports about anti-insect packaging materials and strategies to repel insects were introduced in this study. Furthermore, we suggested new strategies to develop an insect-repelling active packaging materials which could be applied in the food packaging industry.

An Empirical Study on Moderating Effects of Corporate Mentoring between Entrepreneurship and Start-Up Satisfaction (창업가정신이 창업만족도에 미치는 영향에 대한 기업 멘토링의 조절효과에 관한 연구: 부산·경남지역의 창업기업을 대상으로)

  • Jung, Sang Chul;Kim, Young Jin
    • International Area Studies Review
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    • v.21 no.1
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    • pp.119-136
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    • 2017
  • This study investigates the moderating effects of corporate mentoring on the relationship between entrepreneurship and start-up satisfaction. The research was designed to examine a direct relationship between the entrepreneurship on the start-up satisfaction. In addition, indirect impacts of corporate mentoring on the relationship between entrepreneurship and start-up satisfaction. Data was collected by distributing questionnaires through e-mail or direct visit to the participating companies in the Start-up Leading University Project, college start-up clubs, companies in university business incubating centers, and general entrepreneurs in Busan and Gyeongnam areas. Empirical data was then analyzed using the SPSS 18.0 statistical program. The results reveal that such categories as innovation and autonomy in entrepreneurship have a direct positive effect on entrepreneurial satisfaction and the corporate mentoring has a moderating effect only when autonomy has a direct positive effect on start-up satisfaction. It is implied that an improvement of start-up satisfaction may be attained only when mentoring programs are well accepted by entrepreneurs and their workers while working in a free and autonomous environment with a flexible corporate culture. This study may provide the theoretical and practical implications for start-up support organizations such as start-up support groups of Start-Up Leading University Project.

Improved Security for Fuzzy Fingerprint Vault Using Secret Sharing over a Security Token and a Server (비밀분산 기법을 이용한 보안토큰 기반 지문 퍼지볼트의 보안성 향상 방법)

  • Choi, Han-Na;Lee, Sung-Ju;Moon, Dae-Sung;Choi, Woo-Yong;Chung, Yong-Wha;Pan, Sung-Bum
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.19 no.1
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    • pp.63-70
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    • 2009
  • Recently, in the security token based authentication system, there is an increasing trend of using fingerprint for the token holder verification, instead of passwords. However, the security of the fingerprint data is particularly important as the possible compromise of the data will be permanent. In this paper, we propose an approach for secure fingerprint verification by distributing both the secret and the computation based on the fuzzy vault(a cryptographic construct which has been proposed for crypto-biometric systems). That is, a user fingerprint template which is applied to the fuzzy vault is divided into two parts, and each part is stored into a security token and a server, respectively. At distributing the fingerprint template, we consider both the security level and the verification accuracy. Then, the geometric hashing technique is applied to solve the fingerprint alignment problem, and this computation is also distributed over the combination of the security token and the server in the form of the challenge-response. Finally, the polynomial can be reconstructed from the accumulated real points from both the security token and the server. Based on the experimental results, we confirm that our proposed approach can perform the fuzzy vault-based fingerprint verification more securely on a combination of a security token and a server without significant degradation of the verification accuracy.

Cosmetic Application Using Skin Whitening and Anti-microbial effects of Ethyl Acetate and n-Butanol Fractions from Eruca sativa (Eruca sativa 에칠아세테이트와 부탄올 분획물의 미백 및 항균효과를 이용한 화장품 응용연구)

  • Park, Jihye;Lee, Kwang-ho;Kim, Bora
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.3
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    • pp.651-661
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    • 2021
  • Eruca sativa, called arugula, is a perennial plant in the Brassicaceae family, an edible plant commonly used in Italian cuisine. To study as a cosmetic material application E. sativa was extracted with 70% ethanol (ES). Then ES was fractionated using n-hexane, chloroform, ethyl acetate, n-butyl alcohol and water (EHex, EEA, ECHCl3, EBuOH and EDW). EEA showed mushroom tyrosinase inhibitory activity. ES, EEA and EBuOH showed inhibition of tyrosinase activity. As a result, ES is expected to have skin whitening efficacy. ES was applied to 0.05, 0.1% the toner and emulsion formulation to test the stability. The anti-microbial activity of eight bacteria and fungi including Staphylococcus aureus and Propionibacterium acnes which cause dermatitis and acne was evaluated. EEA showed effects in all of microorganisms. The toner and emulsion containing ES with 0.05, 0.1% were passed in the challenge test. At -20, 4, 25, 55 ℃ and daylight, there was no significant change on pH, viscosity for 4 months. However, emulsions had phase separation phenomenon at 55 ℃, so the base formulation needs improvement. In addition, through the skin penetration test, EEA penetrated 0.058% in 6 hr, predicting the clinical efficacy. This means that E. sativa can contribute whitening agent and the synergistic effect of preservatives.

Evaluation of Deterioration Propagation Life of Steel Bridge Paints According to Surface Treatment Methods and Heavy-Duty Painting Types (표면처리방법에 따른 강교용 일반중방식도장계의 열화진행수명 평가)

  • Kim, Gi-Hyeok;Jeong, Young-Soo;Ahn, Jin-Hee;Kim, In-Tae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.1
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    • pp.75-84
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    • 2021
  • In this study, to evaluate deterioration propagation life and deterioration curve of the shop painted and field re-painted steel bridges, accelerated corrosion tests were carried out on 4 types of heavy-duty painting systems with different surface treatments. The surface treatments prior to painting were examined by hand tool(SSPC SP-2), power tool(SP-3,) or blast cleaning(SP-10) considering shop painting and field re-painting. The paint deterioration curves for each painting system and surface treatment were evaluated based on corrosion propagation from the initial paint defects. From the test results, the paint deterioration life of shop painted and field re-painted system was evaluated and compared by using corrosivity categories and durability performance evaluation of structural steel. The deterioration propagation life of shop and field paint was estimated in 18 to 21 years and 5.3 to 8.0 years with atmospheric corrosion category C4.