• Title/Summary/Keyword: technology reliability

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Estimation of Consolidation Characteristics of Soft Ground in Major River Mouth (주요 강하구 연약지반의 압밀 특성 평가)

  • Lee, JunDae;Kwon, YoungChul;Bae, WooSeok
    • Journal of the Korean GEO-environmental Society
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    • v.20 no.2
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    • pp.69-79
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    • 2019
  • The coastal area forms various sedimentary layers according to the environmental conditions such as the topography and geological features of the upper region of the river, ocean currents, and river mouth. Therefore, identifying the characteristics of the marine clay deposited in the coastal area plays a key role in the investigation of the formation of soft ground. In general, alluvial grounds are formed by a variety of factors such as changes in topography and natural environment, they have very diverse qualities depending on the deposited region or sedimentation conditions. The most important thing for the construction of social infrastructures in soft ground areas is economical and efficient treatment of soft ground. In this study, the author collected data from diverse laboratory and field tests on five areas in western and southern offshore with relatively high reliability, and then statistically analyzed them, thereby presenting standard constants for construction design. Correlation between design parameters such as over consolidation ratio, preconsolidation pressure was analyzed using linear and non-linear regression analyses. Also, proposed distribution characteristics of design parameters in consideration of each region's uncertainty through statistical analyses such as normality verification, outlier removal.

An Empirical Study on the Management Performances of Korean Tourism Firms : Focusing on the Economic Effects caused by FTA (FTA의 경제적 효과가 한국 관광기업의 경영성과에 미치는 영향에 관한 연구)

  • Shin, Kwang-Ha;Park, Myung-Chan
    • International Area Studies Review
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    • v.14 no.1
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    • pp.221-254
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    • 2010
  • This study is for analyzing the mgmt performances of Korean tourism firms, operating as preparing strategically against FTA, one of the most importantly external environment in int'l mgmt since in the mid of 1990s. The main purpose can be mentioned to test empirically some relations between the mgmt performances of Korean tourism ones and the economic effects originated from FTA. The dependent variables of mgmt performances are classified with sales, profits and mgmt satisfaction, while the independent one regarding with economic effects from FTA are sorted based on the previous studies with the 2 following factors like direct with inbound/outbound and indirect effects. This study is conducted in two stages. Firstly, the research model is designed by the reviewing relevant theories and previous studies. Secondly, the survey of Korean tourism firms engaging in mgmt activities is implemented by collecting questionnaires. And for testing the hypothesis, the analyzing tools are used for correlation, reliability, validity and multi-regression on SPSS 12.0 and the path analysis of structural equation modeling is activated with AMOS 11.0.

The Data Transmission of Image Storage System of PACS (PACS내 영상저장 장치의 데이터 전송)

  • Cho, EuyHyun;Park, Jeongkyu
    • Journal of the Korean Society of Radiology
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    • v.12 no.6
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    • pp.785-791
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    • 2018
  • Recently, Disk array is widely used as a long term storage device in PACS, but reliability is not enough in relation to annual failure rate of disk. Between October 2016 and February 2017, we scanned the serial port of the hard disk while reading or storing medical images on a PACS reader. The data rate was calculated from the data stored in HDD 99ea that were used in the PCAS image storage device and in HDD 101ea that were used in the Personal Computer. When a CT image was read from a PACS reader, Reading was 87.8% and Writing was 12.2% in units of several tens of megabytes or less. When the CT image was stored in the PACS reader, Reading was 11.4% and Writing was 88.6% in units of several tens of megabytes or less. While reading the excel file on the personal computer, Reading was 75% and Writing was 25% in less than 3 MB, and In the process of storing the excel file on the personal computer, Reading was carried out by 38% and Writing was carreid out 62% in the units of 3 MB or less. The transfer rate of the hard disk used in the PACS image storage device was 10 GB/h, and the transfer rate per hour of the hard disk of the personal computer was 5 GB / h. Annual failure rate of hard disk of image storage system is 0.97 ~ 1.13%, Annual failure rate of Hard Disk of personal computer is 0.97 ~ 1.13%. the higher transfer rate is, the higher annual failure rate is. These results will be used as a basis for predicting the life expectancy of the hard disk and the annual failure rate.

Test and Evaluation for GNSS based Lane Level Precise Positioning User System (위성항법 기반 차로구분 정밀위치결정 사용자 시스템 시험 평가)

  • Lee, Jung-Hoon;Lee, Sangwoo;Ahn, Jongsun;Im, Sunghyuck;Choi, Yunseong;Jang, Youngsu;Lee, Dongchul;Heo, Moon-Beom
    • Journal of Advanced Navigation Technology
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    • v.22 no.6
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    • pp.566-576
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    • 2018
  • The C-ITS requires the lane level positioning of the vehicle in the land transportation environment, and it is most effective to utilize the GNSS. In the precision positioning system based on satellite navigation, the evaluation of dynamic environment of lane level positioning performance should be accompanied and the evaluation system configuration should be preceded. In this paper, we selected performance indicators, assessment equipment, and reliability of reference equipment for evaluation of precision positioning user systems based on the GNSS. The performance evaluation system described above is applied to a real system, and the performance evaluation tool developed for the evaluation system is described. The numerical performance evaluation was carried out based on the data collected by carrying out the actual testbed driving. The performance evaluation by the actual driving trajectory and driving image comparison was performed to derive and analyse the evaluation results of the vehicle lane level positioning user system.

Exploring Job Aptitude through Analyzing the Relationship between Six Types of GEOPIA and MBTI's four Function Types (도형심리검사 GEOPIA 6가지 유형과 MBTI 4기능 유형 간 관계연구를 통한 직업적성탐구)

  • Oh, Mi-Ra;Choi, Jeang-Han
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.9
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    • pp.82-92
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    • 2019
  • The purpose of this study was to analyze the relationship and degree of agreement between the six types of Geometry Psychological Assessment (GEOPIA) and four functions of the Myers-Briggs Type Indicator (MBTI) personality test, and to investigate the appropriate level of vocational aptitude commonly recommended by each tool. A total of 377 adult men and women from Korea, aged between 19 and 70 years, were tested using GEOPIA and the MBTI. Cronbach's alpha was calculated to verify the validity and reliability of the measuring tools, and the mean and standard deviation of each variable were calculated. Also, a cross-sectional analysis was conducted to examine the relationship between GEOPIA and the MBTI. The results showed that Round/Triangle (RT) types, Round/Box (RB) types, Triangle/Box (TB) types and Box/Curve (BC) types among the GEOPIA personality types are highly related to MBTI's Sensing/Thinking (ST) types. GEOPIA RC types were related to Intuition/Feeling (NF) and Sensing/Feeling (SF) types, and TC types were highly related to Intuition/Thinking (NT) types. Based on the common characteristics of the two tests, the findings suggest appropriate levels of vocational aptitude. Through this research, it was confirmed that GEOPIA (a Korean psychology and personality test) can be used in counseling, coaching, and education, and above all, is a reliable tool for vocational psychological assessment to search for career aptitude.

Antifouling Effect of an Ultrasonic System Operating at Different Frequencies (주파수 변동에 따른 초음파방오장비의 파울링제거효과)

  • Bae, Jin-Woo;Park, Guan-Sik;Ru, Myung-Lok;Park, Goun-Ha
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.5
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    • pp.609-616
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    • 2019
  • When the fouling of a vessel occurs, its resistance at sea increases and there is a corresponding increase in fuel consumption. The maintenance cost of the vessel also increases because it is time-consuming to remove the fouling. To solve this problem and minimize environmental contamination of sea-water, there have been recent developments in anti-fouling paints as self-polishing copolymers that not include toxic elements such as tin. When these conventional techniques are applied to vessels, polishing is promoted during the operation whereby friction or vibration with seawater occurs. This leads to enhanced anti-fouling performance. However, when fouling is intensified such as during an anchorage, there is no flow of seawater and polishing is suppressed. This leads to a deterioration of the performance of anti-fouling. To solve these problems, we developed a system that induces vibration in a vessel during anchorage. As such, the deterioration of polishing due to insuf icient flow of seawater is inhibited. The reliability of the ultrasonic antifouling system was evaluated by calculating its repeatability. The removal efficiency of fouling of the proposed system was qualitatively evaluated using test specimens. The test revealed that the value of the coefficient of variation for the reproducibility of the frequency and amplitude was 0.2 % and 4.0 % on average. The degree of fouling of the specimens was the highest at 73.3 g in the No.5 sepcimen. Moreover, efficiency of fouling removal was 93.2 % on average compared to the specimens without the proposed system.

Standardization Method for Vessel Collision Warning Service Using WAVE Communication Technology (WAVE 선박충돌경보 서비스를 위한 표준화 방안 개발에 관한 연구)

  • Kang, Won-Sik;Kim, Young-Du;Choi, Choong-Jung;Park, Young-Soo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.5
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    • pp.542-549
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    • 2019
  • Maritime accidents, such as the collision of a fishing boat in Incheon's Yeongheung Island, result in several casualties and property damage, even if they occur just once. To prevent such accidents, the Incheon Metropolitan Government is implementing safety management policies; further, they will provide ship collision warning services to prevent collisions on WAVE (Wireless Access in Vehicular Environment) communication-based ship safety operation pilot projects. However, to realize these objectives, a service standardization method is required that defines specific service types, configurations, and systems, which should be prepared based on user requirement analyses. In this study, a standardization method of WAVE communication-based collision warning service was developed by analyzing the requirements of the vessel operators subject to the services and related authorities. This will help improve the quality of service, ensuring professionalism and reliability through continuous improvement and efforts for standardization, as well as data derived from demonstration projects. Therefore, it is expected to help prevent maritime accidents to a considerable extent.

A Review on Measurement Techniques and Constitutive Models of Suction in Unsaturated Bentonite Buffer (불포화 벤토나이트 완충재의 수분흡입력 측정기술 및 구성모델 고찰)

  • Lee, Jae Owan;Yoon, Seok;Kim, Geon Young
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.17 no.3
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    • pp.329-338
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    • 2019
  • Suction of unsaturated bentonite buffers is a very important input parameter for hydro-mechanical performance assessment and design of an engineered barrier system. This study analyzed suction measurement techniques and constitutive models of unsaturated porous media reported in the literature, and suggested suction measurement techniques and constitutive models suitable for bentonite buffer in an HLW repository. The literature review showed the suction of bentonite buffer to be much higher than that of soil, as measured by total suction including matric suction and osmotic suction. The measurement methods (RH-Cell, RH-Cell/Sensor) using a relative humidity sensor were suitable for suction measurement of the bentonite buffer; the RH-Cell /Sensor method was more preferred in consideration of the temperature change due to radioactive decay heat and measurement time. Various water retention models of bentonite buffers have been proposed through experiments, but the van Genuchten model is mainly used as a constitutive model of hydro-mechanical performance assessment of unsaturated buffers. The water characteristic curve of bentonite buffers showed different tendencies according to bentonite type, dry density, temperature, salinity, sample state and hysteresis. Selection of water retention models and determination of model input parameters should consider the effects of these controlling factors so as to improve overall reliability.

Improvement of Access Control at Partially Grade-Separated Intersection (단순입체교차 도로의 진출입로 설치 금지구간 개선방안)

  • Kim, Young-Jin;Kim, Jin-Uk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.12
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    • pp.725-733
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    • 2018
  • With urbanization projects involving trunk roads progressing, many simple interchanges, which separate passing traffic into the main traffic and access subtraffic, are being constructed to maximize the traffic capacity. Under the current Road Connection Rule, the access-prohibited section in an interchange is determined based on the access lane and limit distance in the complete interchange road, but separate criteria for the simple interchange are not defined. This may cause confusion in the Road Management Office's determination of the access-prohibited section in the simple interchange, or lead to the application of the criteria for the access-prohibited section in the complete interchange without considering the features of such interchange. This study conducted a comparative analysis of the domestic and overseas systems related to the installation of access section in trunk roads, such as general national roads. This paper presents a survey of the methods for applying the access-prohibited section in the interchange along with the actual cases and proposes improvement measures for a rational calculation of the access prohibited installation section in the simple interchange to minimize the downsides associated with the application of the extremely strict criteria. The proposed road connection rule improvement measures based on the consideration of the purpose of installing the simple interchange and on the consideration the features of the simple interchange are expected to prevent administration confusion by the field road management offices as well as the waste of unnecessary efforts and costs by petitioners so they can boost the service satisfaction for people and the administrative reliability.

A Security Nonce Generation Algorithm Scheme Research for Improving Data Reliability and Anomaly Pattern Detection of Smart City Platform Data Management (스마트시티 플랫폼 데이터 운영의 이상패턴 탐지 및 데이터 신뢰성 향상을 위한 보안 난수 생성 알고리즘 방안 연구)

  • Lee, Jaekwan;Shin, Jinho;Joo, Yongjae;Noh, Jaekoo;Kim, Jae Do;Kim, Yongjoon;Jung, Namjoon
    • KEPCO Journal on Electric Power and Energy
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    • v.4 no.2
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    • pp.75-80
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    • 2018
  • The smart city is developing an energy system efficiently through a common management of the city resource for the growth and a low carbon social. However, the smart city doesn't counter a verification effectively about a anomaly pattern detection when existing security technology (authentication, integrity, confidentiality) is used by fixed security key and key deodorization according to generated big data. This paper is proposed the "security nonce generation based on security nonce generation" for anomaly pattern detection of the adversary and a safety of the key is high through the key generation of the KDC (Key Distribution Center; KDC) for improvement. The proposed scheme distributes the generated security nonce and authentication keys to each facilities system by the KDC. This proposed scheme can be enhanced to the security by doing the external pattern detection and changed new security key through distributed security nonce with keys. Therefore, this paper can do improving the security and a responsibility of the smart city platform management data through the anomaly pattern detection and the safety of the keys.