• Title/Summary/Keyword: reliability and safety

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Developing Standards for Measuring Consumer's Damage in Internet Shopping Mall (인터넷쇼핑몰 소비자 피해 측정을 위한 척도개발 -패션상품 쇼핑을 중심으로-)

  • Chang, Hyun-Sun
    • Journal of Family Resource Management and Policy Review
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    • v.11 no.4
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    • pp.21-36
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    • 2007
  • As online shopping is expanding rapidly, the damages undergone by consumers are also dramatically increasing. This research mainly focused on the damages experienced through Internet shopping. The purpose of this study was to develop a standardized scale to measure damages sustained through an Internet shopping mall. A preliminary 35-item scale was developed through a literature review, and 1,230 consumers responded to an online survey using the preliminary scale. This research was supported by the surveys conducted on consumers who had previously shopped at an Internet fashion mall. This research was conducted with the intention of not only supplying academic data on the damage sustained by consumers, but also understanding the consumers' basic behavior patterns. Then a series of tests, such as test-retest, item-to-total correlation, Cron bach's reliability coefficient and factor analysis, were conducted using the survey data and a final scale with 26-items was constructed in the end. The damage sustained in Internet shopping malls scale for consumers consisted of three factors: 1. Trouble with safety 2. Trouble with payment and delivery; and 3. Trouble with after-sales services.

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A Novel Islanding Detection Scheme without Non Detection Zone (불검출영역이 없는 새로운 단독운전 검출기법)

  • Jo, Yeong-Min;Kim, Dong-Gyun;Cho, Sang-Yoon;Song, Seung-Ho;Choy, Ick;Lee, Young-Kwoun;Choi, Ju-Yeop
    • The Transactions of the Korean Institute of Power Electronics
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    • v.20 no.6
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    • pp.540-549
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    • 2015
  • Unintentional islanding results in safety hazards, reliability, and many other issues. Therefore, the islanding detection of a power conditioning system of a distributed generation, such as a grid-connected photovoltaic inverter, is a key function for standard compliance. Currently, many anti-islanding schemes have been examined, but existing anti-islanding schemes have poor power quality and non-detection zone issues. Therefore, this study analyzes the non-detection zone in a more deliberate manner than the existing analysis of the non-detection zone and proposes a new anti-islanding scheme, which has negligible power quality degradation and no non-detection zone. Simulation and experimental results validate that the proposed scheme shows much better performance than other existing schemes.

Development of Propulsion Subsystem for KOMPSAST (다목적 실용위성의 추진시스템 개발)

  • 최진철;윤효철
    • Journal of the Korean Society of Propulsion Engineers
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    • v.2 no.3
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    • pp.80-89
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    • 1998
  • Propulsion subsystem transfers KOMPSAT into mission orbit and controls its attitude. Design factor consists of structure safety, electrical circuit design, consumable power estimation of thermal hardwares, damping device design of fuel transient pressure, and system configuration design by considering plume effect from thruster firing. System level analysis should be performed for verification of system design under launch vehicle and orbital environment. Electrical functional test of thermal control hardware, proof pressure test, cleanliness verification test, and internal/external leakage test of fuel feeding system should be carried out for performance estimation of propulsion system. Design and assembly process of propulsion subsystem was depicted and reliability of system was verified by test analysis in this paper.

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Guided Missile Initiation Technologies, Now and Tomorrow (유도무기 착화기술의 현황과 발전 전망)

  • 장석태
    • Journal of the Korean Society of Propulsion Engineers
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    • v.4 no.1
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    • pp.102-108
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    • 2000
  • The comparative evaluation/analysis of the initiation technologies currently being used, and the advanced initiation technologies currently being developed lot the aerospace and defense applications was performed. The evaluation criteria used were the compliance, performance, reliability, safety, and cost. The results clearly indicate that there is no one single initiation technology that will satisfy entire spectrum of initiation system requirements. Each initiation system architecture would require different initiation technologies that will satisfy the overall system performance requirements. However, laser initiation, particularly, the laser diode initiation has been getting more attention in recent years. The laser diode initiation, for most part, eliminates EMI and ESD concerns. In addition, laser diode initiation system can also be designed into relatively small packages, are optically connected systems by very light weight cables, are relatively easily designed to meet variety of initiation system requirements. Due to the these compelling factors, laser diode initiation has potential of becoming common initiation systems for many different aerospace and defense application.

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Analysis on motions characteristics of Floaters using two-dimensional Boundary Element Method (2차원 경계요소법을 이용한 부유체의 운동 특성 연구)

  • Baek, Mi-Seon;Seong, Yu-Chang
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.06a
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    • pp.136-138
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    • 2013
  • Current, standards light buoys as maritime traffic safety facilities have 10 different types of buoys and the smallest size of those is 4.4m. Therefore, making for easy replacement and repair parts for the type of small light buoys is proposed. Meanwhile, position reliability of floaters by external forces in the environment fall and stability examination should be considered for prohibiting accidents as loss. In this paper, a new light buoy is analyzed on Encounter Frequency types using commercial program and fluid forces is simulated on cross-sectional shape of the float using two-dimensional Boundary Element Method(BEM).

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A Study on Access Control Through SSL VPN-Based Behavioral and Sequential Patterns (SSL VPN기반의 행위.순서패턴을 활용한 접근제어에 관한 연구)

  • Jang, Eun-Gyeom;Cho, Min-Hee;Park, Young-Shin
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.11
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    • pp.125-136
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    • 2013
  • In this paper, we proposed SSL VPN-based network access control technology which can verify user authentication and integrity of user terminal. Using this technology, user can carry out a safety test to check security services such as security patch and virus vaccine for user authentication and user terminal, during the VPN-based access to an internal network. Moreover, this system protects a system from external security threats, by detecting malicious codes, based on behavioral patterns from user terminal's window API information, and comparing the similarity of sequential patterns to improve the reliability of detection.

Design of a MEMS sensor array for dam subsidence monitoring based on dual-sensor cooperative measurements

  • Tao, Tao;Yang, Jianfeng;Wei, Wei;Wozniak, Marcin;Scherer, Rafal;Damasevicius, Robertas
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.10
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    • pp.3554-3570
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    • 2021
  • With the rapid development of the Chinese water project, the safety monitoring of dams is urgently needed. Many drawbacks exist in dams, such as high monitoring costs, a limited equipment service life, long-term monitoring difficulties. MEMS sensors have the advantages of low cost, high precision, easy installation, and simplicity, so they have broad application prospects in engineering measurements. This paper designs intelligent monitoring based on the collaborative measurement of dual MEMS sensors. The system first determines the endpoint coordinates of the sensor array by the coordinate transformation relationship in the monitoring system and then obtains the dam settlement according to the endpoint coordinates. Next, this paper proposes a dual-MEMS sensor collaborative measurement algorithm that builds a mathematical model of the dual-sensor measurement. The monitoring system realizes mutual compensation between sensor measurement data by calculating the motion constraint matrix between the two sensors. Compared with the single-sensor measurement, the dual-sensor measurement algorithm is more accurate and can improve the reliability of long-term monitoring data. Finally, the experimental results show that the dam subsidence monitoring system proposed in this paper fully meets the engineering monitoring accuracy needs, and the dual-sensor collaborative measurement system is more stable than the single-sensor monitoring system.

Accelerated Life Test Selection Study for Life Evaluation of Engine Type Drive Axle for Forklift (지게차용 엔진식 드라이브 액슬 수명평가를 위한 가속수명시험 선정 연구)

  • Jun-Young Kim;Yeong Jun Yu;Chul-Hee Lee
    • Journal of Drive and Control
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    • v.20 no.3
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    • pp.9-14
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    • 2023
  • In this paper, the selection of a reliable accelerated life test code for a 2-ton forklift was accomplished by choosing the driving resistance coefficient failure-free test time based on a 10,000-hour B10 life. The overall life and average equivalent load of the vehicle were then calculated based on actual driving test conditions using the selected driving resistance coefficient. The gear train's accelerated life test code was selected by adjusting the equivalent load to a torque and rotation speed that did not exceed 125%(about 75HP) of the vehicle rated power. The safety of the test standards was validated by conducting an actual accelerated life test utilizing the proposed test method in this study and comparing the test result with the corresponding theoretical value. It is anticipated that the reliability of the accelerated life test in this paper will be enhanced, by incorporating actual driving performance data collected directly from the forklift and adjusting the conditions used in developing the accelerated life test code.

Research on Consumer's Food Purchasing Intentions through Internet Shopping Mall (인터넷 쇼핑몰 이용 소비자의 식품 구매 의도 분석)

  • Kim, Sung-Hee;Joo, Na-Mi
    • Journal of the Korean Society of Food Culture
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    • v.22 no.6
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    • pp.705-712
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    • 2007
  • In spite of the fact that the food group(Food, Drinks and Health foods & Agricultural and Marine products) occupies little position in total sales of Internet shopping mall, the food group's sales in cyber shopping mall in 2006 have increased 678.1% over 5 years. In addition to the fact that the food consumption pattern has changed from quality-oriented to convenience, health and safety-oriented, the need to decrease the opportunity cost created by housework is rising in the context of increase of women's work participation rate. The wind of change like these will become the foundation on which cyber food industry will be developed. The factors having an effect on consumer purchasing intentions when one buy foods through internet shopping malls are researched in this thesis. For the investigation, women of 697 were surveyed by a questionnaire, and the data were analyzed by the SPSS for WINDOW(Version 12.0). The result is as follows: Factors having an effect on food purchasing intentions are Convenience(Timesaving, Troublesomeness), Customer service(Responsiveness, Reliability, Empathy, Tangibility), Perceived Customer Risk(Economic, Social, Performance risk) and Shopping experience(Easy to find out, Easy process for payment) in order.

Dynamic Material Testing of Aged Concrete Cores From the Outer Wall of the High-Flux Advanced Neutron Application Reactor

  • JaeHoon Lim;Byoungsun Park;Jongmin Lim;Yun-Young Yang;Sung-Hyo Lee;Sang Soon Cho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.22 no.2
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    • pp.139-144
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    • 2024
  • Concrete structures must maintain their shielding abilities and structural integrity over extended operational periods. Despite the widespread use of dry storage systems for spent nuclear fuel, research on the properties of deteriorated concrete and their impact on structural performance remains limited. To address this significant research gap, static and dynamic material testing was conducted on concrete specimens carefully extracted from the outer wall of the High-flux Advanced Neutron Application ReactOr (HANARO), constructed approximately 30 years ago. Despite its age, the results reveal that the concrete maintains its structural integrity impressively well, with static compression tests indicating an average compressive strength exceeding the original design standards. Further dynamic property testing using advanced high-speed material test equipment supported these findings, showing the consistency of dynamic increase factors with those reported in previous studies. These results highlight the importance of monitoring and assessing concrete structures in nuclear facilities for long-term safety and reliability.