• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.29 no.6C
• /
• pp.321-329
• /
• 2009

Laboratory compressive test was conducted on 6 different types of rock in order to investigate the characteristic of critical strain under uniaxial and triaxial stress condition. The results of uniaxial compressive test mostly ranged within 1~100MPa, the critical strain was also located between 0.1~1.0%. Therefore the results distributed within the upper and lower boundary proposed by Sakurai (1982). And the failure/critical strain ratio (${\varepsilon}_f/{\varepsilon}_0$) showed between 1.0~1.8 value depending on the uniaxial compressive strength. The results of critical strain by triaxial compressive test showed below 0.8% value for all test, the M value calculated from uniaxial and triaxial compressive test results ranged 1.0~8.0 for most of rock specimens. It is concluded that failure strain (${\varepsilon}_{f3}$) of rock mass, which is in triaxial stress condition is larger than the results of uniaxial stress condition (${\varepsilon}_{f1}$) by 1.0~8.0 times and value showed 1.0~1.8 larger value than critical strain (${\varepsilon}_{01}$). Therefore it is a conservative way for rock tunnel to use critical strain (${\varepsilon}_{01}$) calculated from a uniaxial compressive strength on tunnel displacement monitoring.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.7
• /
• pp.1044-1050
• /
• 2021

After the occurrence of several passenger ship accidents in Korea, various systems are being developed for passenger ship safety management. A total of 162 passenger ships operate along the coast of Korea, of which 105 (65 %) are car-ferries with open vehicle decks. The car-ferry has a navigation pattern that passes through 2 to 4 islands. Safety inspections at the departure point(home port) are carried out by the crew, the operation supervisor of the operation management office, and the maritime safety supervisor. In some cases, self-inspections are carried out for safety inspections at layovers. As with any system, there are institutional and practical limitations. To this end, this study was conducted to suggest a method of detecting a vehicle using image processing and linking it to the calculations for ship stability. For vehicle detection, a method using a difference image and one using machine learning were used. However, a limitation was observed in these methods that the vehicle could not be identified due to strong background lighting from the pier and the ship in the cases where the camera was backlit such as during sunset or at night. It appears necessary to secure sufficient image data and upgrade the program for stable image processing.

• Journal of Korean Institute of Industrial Engineers
• /
• v.40 no.1
• /
• pp.43-51
• /
• 2014

Statistical process control (SPC) is an important technique for monitoring and managing the manufacturing process. In spite of its easiness and effectiveness, some problematic sides of application exist such that the SPC techniques are hardly reflect the changes of the process conditions. Especially, update of control limits at the right time plays an important role in acquiring a reasonable performance of control charts. Therefore, we propose the control chart performance evaluation index (CPEI) based on count data model to monitor and manage the performance of control charts. The CPEI could indicate the degree of control chart performance and be helpful to detect the proper update cycle of control limits in real time. Experiments using real manufacturing data show that the proper update intervals are made by proposed method.

• Journal of the Korean Geosynthetics Society
• /
• v.17 no.2
• /
• pp.9-18
• /
• 2018

In this study, a field model experiment was performed to analyze the bahavior of slope during failure. It was analyzed through x-MR control chart method with inverse displacement and K-value. As a result, the portent was confirmed at 4 minutes before slope failure in Case 1. The change of the control limit line according to moving range was analyzed and it was effective to apply K = 3. Use of the inverse displacement and x-MR control chart method will be useful for the prediction of abnormal behavior through quick and objective judgment. Prediction of slope failure using control chart method can be used as basic data of slope measurement management standard, and it can contribute in reduction of life and property damage caused by slope disaster.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.12
• /
• pp.197-204
• /
• 2011

In this paper, There is a study of a smartphone-based App for e-learning when the process control of manufacturing. First, That is obtained the control limit lines after inputted by the measured data and able to look up the assignable causes and then can display those causes. A User of this App can access the record about assignable causes using the record menu and can use with an e-Learning tool. Because that were provided in the form of a control process theory and bulletin announcements. Helped to exchange information. In addition, the user's guide how to use this App. The result of this process control is provided by charts. The alarm message to the alertsymbol, depending on the level of color clearly was designed to UI which displays the results. After the questionnaire responses with respect to satisfaction of Utilization and satisfaction of the learning experience. The Utilization' satisfaction results Appeared that 82% of the participants were satisfied. And The learning's satisfaction results Appeared that 90% of the participants were satisfied.

• Korean Journal of Food Science and Technology
• /
• v.36 no.5
• /
• pp.711-716
• /
• 2004

Gamma irradiation was applied to dried pollack to improve its microbiological quality and evaluate quality stability of irradiated samples. Thermoluminescence (TL) properties of minerals separated from irradiated samples were measured for possible use in identifying irradiation treatment. Dried pollack was packaged in commercial unit (PVC film, 0.06 mm thickness) and stored at $15{\pm}1^{\circ}C$ for 6 months. Samples showed over $10^4\;CFU/g$ in total aerobic bacteria or yeasts&molds, which increased during storage, reaching $10^6-10^7\;CFU/g$ at 3rd month of storage. Irradiation at 3 kGy was effective for improving hygienic quality for 6 months, keeping microbial population under 20 CFU/g. Gamma irradiation at 3 kGy or less did not significantly influence physicochemical quality attributes, such as browning, TBA value, volatile basic nitrogen, trimethylamine, and sensory properties, whereas storage time remarkably induced quality changes of dried pollack. TL analysis was proved suitable for identifying irradiated from non-irradiated samples over 6 months of storage.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.26 no.6
• /
• pp.212-221
• /
• 2022

In this paper, the evaluation procedure applying the limit state design method is studied to be consistent with the newly issued bridge design code in Korea. The live load factor for evaluation is proposed by calibrating for the target reliability index through reliability analysis. Using the actual bridge information collected for the representative bridge types in Korea, the load effects of the design live loads for the previous and current design codes are calculated and compared. The live load factor is calibrated through reliability analysis using the minimum required strength which equals to the load effect obtained for the example bridge. Bridge evaluation is performed by applying the live load factors for the evaluation level as well as design level. The load rating result is generally increased by applying the limit state design method compared to the previous design method and applying the proposed load factor for lowered target reliability index further increased the rating result.

• Journal of Korean Society for Quality Management
• /
• v.12 no.2
• /
• pp.15-24
• /
• 1984

Since W.A. Shewhart (1931) developed the quality control method using the control chart, many theoretical and empirical works about such an analytical method have been done. However there are two major methods relating to the control chart analysis; the conventional 3 sigma control method and the warning limit method which has been suggested as a modification of the former. The conventional 3 sigma method requires to take a remedial action only when a quality characteristic is beyond the control limit (3 sigma). However, once a quality characteristic is over the control limit, searching and repairing an assignable cause requires time consuming job and high costs. Therefore if we set the warning limit between the central line and the control limit, we will be able to take remedial measures before too late. In spite of its advantage, much attention has not been paid to use the control chart with warning limit in Korean industries. The main object of this study is to examine improvement of quality and productivity when the control chart with warning limit is used.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.10c
• /
• pp.607-609
• /
• 2004

기존 웹 서비스 모델에서는 Client-Server 모델을 기반으로 서비스 영역의 설정과 서비스 지원 방안에 대한 연구들을 수행했다. 그러나 기존 웹 서비스 모델들은 주로 정보의 수집을 통한 검색기반 서비스 모델을 제시하고 있으며, 이렇게 수집된 정보들을 가공하거나 분석하는 등의 처리방안을 지원하지 못하고 있다. 기존 웹 서비스 모델의 한계를 극복하기 위해 서비스 환경의 다양성 및 확장성을 수용하고, 효율적인 웹 서비스를 제공할 수 있는 기반 구조가 필요하다. 지식기반 웹 서비스는 광역 환경에 산재한 웹 서비스들을 관리하고 최적의 서비스 성능을 확보하기 위한 기술들을 포함한다. 온톨로지를 기반으로하는 지식 기반의 웹 서비스를 이용한다면 웹을 통해 정보를 찾는 방법과 정보를 입수하는 방법을 고려하여 최적의 웹 서비스를 받을 수 있다. 본 논문에서는 광범위한 비즈니스 시장을 갖는 웹 서비스 환경의 기본 서비스 모델을 확장하여 최적의 서비스 제공자를 동적으로 선정하고, 목적 서비스의 효율성을 향상 시 킬 수 있는 지식기반 웹 서비스 모델을 연구하였다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2003.11b
• /
• pp.793-796
• /
• 2003

B2B 전자상거래와 같이 XML을 이용한 정보교환이 확산되고 있으며 이에따라 상호 교환되는 정보에 대하여 체계적이고 안정적인 저장 관리가 요구되고 있다. 이를 위해 XML 응용과 데이터베이스 연계를 위하여 다양한 연구가 XML DTD와 관계형 데이터베이스 중심으로 수행되었다. 그러나 XML DTD가 다양한 데이터 타입 및 표현의 한계 때문에 관계형 데이터베이스와 원활한 연계가 불가능하게 되었다. 그러므로 다양한 데이터 타입과 데이터 표현에 강력한 XML Schema에 대한 연구가 필요하게 되었다. 또한 계층구조를 2차원 정보로 변환하는 방법에 의해서 각 구조화된 정보를 관계형 데이터베이스로 저장하기 위한 데이터 모델링과 XML schema 모델링이 요구된다. 본 논문에서는 XML schema로 정의된 XPDL 정의 스키마를 UML로 변환하는 방법론과 UML을 RDB 스키마로 변환하는 방법론을 제시함으로써, 워크플로우 정의 언어인 XPDL 정의 스키마를 토대로 관계형 데이터베이스의 스키마를 확정하는 방법론을 제안하였다.