• Title/Summary/Keyword: Construction joint

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Development of a Data Reference Model for Joint Utilization of Biological Resource Research Data (생물자원 연구데이터의 공동 활용을 위한 데이터 참조모델 개발)

  • Kwon, Soon-chul;Jeong, Seung-ryul
    • Journal of Internet Computing and Services
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    • v.19 no.4
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    • pp.135-150
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    • 2018
  • The biological resources research data around the world are not only very critical themselves but should be shared and utilized. Up to now, the biological resources have been compiled and managed individually depending on the purpose and characteristics of the study without any clear standard. So, in this study, the data reference model would be suggested which is applicable in the phase ranging from the start of the construction of the information system and which can be commonly used. For this purpose, the data model of the related information system would be expanded based on the domestic and foreign standards and data control policy so that the data reference model which can be commonly applicable to individual information system would be developed and its application procedure would be suggested. In addition, for the purpose of proving the excellence of the suggested data reference model, the quality level would be verified by applying the Korgstie's data model evaluation model and its level of data sharing with the domestic and foreign standards would be compared. The test results of this model showed that this model is better than the conventional data model in classifying the data into 4 levels of resources, target, activities and performances and that it has higher quality and sharing level of data in the data reference model which defines the derivation and relation of entity.

Experimental Studies on Bond and Splice Performance of Splice Sleeve for Connecting Rebar (철근연결용 스플라이스 슬리브의 이음 및 부착성능에 대한 실험적 연구)

  • Kang, Duk Man;Park, Yong Gul;Lee, Hyeon Gi;Moon, Do Young
    • Journal of the Korean Society for Railway
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    • v.20 no.2
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    • pp.257-264
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    • 2017
  • The PC (Precast Concrete) construction method is a technique where concrete members that have been produced in a plant are constructed on site. Thus, continuity and secure integration of a structure that can be obtained by connecting rebars at splicing joint for PC members are the main areas of concern for this method. To evaluate the splicing and bonding performance according to application of a splice sleeve for connecting rebar in this research study, the diameter of rebar, development length, grouting strength etc. were set as variables. The performance and stiffness of splicing according to the development length of grout strength were measured and evaluated. In addition, by conducting comparative analysis on each of the variables, the factors that affected the splice sleeve for connecting rebar were discussed. The results confirmed that the strength and stiffness of the splice sleeve for connecting rebar were significantly affected by the development length while the increase in performance according to grout strength was not as significant.

A Study on the Concept of Convergence and Combined Combat Based on South Korean-style AICBM for the Victory of Future War (미래전 승리를 위한 한국형 AICBM 기반 융·복합 전투개념 연구)

  • Jung, Min-Sub;Lee, Woong;Park, Sang-Hyuk
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.2
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    • pp.321-325
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    • 2020
  • The purpose of this study is to re-concept the future battle of the Army, which combines the effects of advanced technology on the concept of combat and the AICBM technology. The "war concept" changes with the times, and can be seen through the following two examples. First, it is a concept that achieves relative superiority by analyzing enemies. A case in point is the U.S. military's development of a "public joint battle" into a "multi-domain operation." Second, it is 'science and technology' that leads to a change in the concept of combat. A case in point is that the firepower warfare on land and sea in World War I developed from World War II to "air warfare" due to the emergence of aircraft. In this regard, the U.S. military is focusing on the concept of fighting in line with the future operational environment based on high-tech science and technology and the construction of the future military through the creation of the "Future Command." Therefore, our military needs to utilize the major technologies of the fourth industrial revolution as an opportunity to develop the concept of future combat, and the future war will greatly affect the development of the concept of advanced science and technology carrying out war, as AIC technology based on the fourth industrial revolution will promote innovation in defense operations in the form of super-connected, super-intelligence and super-integration. Therefore, this study will present the impact of advanced technology on the concept of combat and the concept of battle of the future Army incorporating the technology of AICBM.

Economic Analysis with Development of Rapid Setting Alumina-based Binder for Road Repair (알루미나계열 속경성 도로 보수재료 개발에 따른 경제성 분석)

  • Yang, Hee-Jun;Yang, Min-Jae;Hong, Sung-In;Ann, Ki-Yong
    • Journal of the Korea Concrete Institute
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    • v.29 no.1
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    • pp.3-10
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    • 2017
  • In case of Korea highways, about 60% of highways are paved by concrete and more than 50% of them were repaired due to reduction in required performance such as damage in pave or joint and delamination of cover pavement. However, repairing old material in such structure generally costs a lot of money and induces difficulty in maintenance. Thus, enhanced material for ensuring economic efficiency should be developed. The present study designed concrete mixtures with 3 levels of replacement using OPC (0, 10, 20%) in calcium aluminate cement and to evaluate material performance for load pavement, experimental works for setting time, compressive strength and flexural strength were carried out on those materials. As a result, 20% replacement for OPC was determined as an optimized material in terms of required physical performance and its unit price. Moreover, to determine cost in load pavement economy analysis using a program (CA4PRS) was conducted with widely used paving materials. Result showed that application for 20% replacement for OPC was the most efficient in economical aspect, arising from 4.052 and 1.577 billion won for total construction and user cost, respectively.

Necessity of the Physical Distribution Cooperation to Enhance Competitive Capabilities of Healthcare SCM -Bigdata Business Model's Viewpoint- (의료 SCM 경쟁역량 강화를 위한 물류공동화 도입 필요성 -빅데이터 비즈니스 모델 관점-)

  • Park, Kwang-O;Jung, Dae-Hyun;Kwon, Sang-Min
    • Management & Information Systems Review
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    • v.39 no.3
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    • pp.17-35
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    • 2020
  • The purpose of this study is to develop business models for current situational scenarios reflecting customer needs emphasize the need for implementing a logistics cooperation system by analyzing big data to strengthen SCM competitiveness capacities. For healthcare SCM competitiveness needed for the logistics cooperation usage intent, they were divided into product quality, price leadership, hand-over speed, and process flexibility for examination. The wordcloud results that analyzed major considerations to realize work efficiency between medical institutes, words like unexpected situations, information sharing, delivery, real-time, delivery, convenience, etc. were mentioned frequently. It can be analyzed as expressing the need to construct a system that can immediately respond to emergency situations on the weekends. Furthermore, in addition to pursuing communication and convenience, the importance of real-time information sharing that can share to the efficiency of inventory management were evident. Accordingly, it is judged that it is necessary to aim for a business model that can enhance visibility of the logistics pipeline in real-time using big data analysis on site. By analyzing the effects of the adaptability of a supply chain network for healthcare SCM competitiveness, it was revealed that obtaining competitive capacities is possible through the implementation of logistics cooperation. Stronger partnerships such as logistics cooperation will lead to SCM competitive capacities. It will be necessary to strengthen SCM competitiveness by searching for a strategic approach among companies in a direction that can promote mutual partnerships among companies using the joint logistics system of medical institutes. In particular, it will be necessary to search for ways to utilize HCSM through big data analysis according to the construction of a logistics cooperation system.

Selection of Postweld Heat Treatment Condition of a High-Temperature and High-Pressure Forged Valve (고온고압용 단조밸브의 용접후열처리 조건 선정)

  • Park, Jae-Seong;Heo, Ki-Moo;Yoon, Sung-Hoon;Moon, Yoon-Jae;Lee, Jae-Heon
    • Plant Journal
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    • v.10 no.2
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    • pp.48-59
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    • 2014
  • Coupons which have same figure as weld joint of the forged steel valves and 1 inch nominal weld thickness were manufactured using ASTM A182 F92 material. After welding with GTAW method, the welded specimens have been post-weld heat treated at $705^{\circ}C$, $735^{\circ}C$, $750^{\circ}C$, $765^{\circ}C$, $795^{\circ}C$ and $825^{\circ}C$ for 1 hour per 1 inch nominal weld thickness each (Group 1) to evaluate characteristics of welds based on various holding temperature. Indeed, 3 welded specimens were post-weld heat treated for 30 minutes, 1 hour and 2 hour (Group 2) at $735^{\circ}C$ to evaluate characteristics of welds based on various holding time. Hardness values were measured at the weld metal, heat affected zone and base metal to observe hardness change depending on the condition. As a result of the evaluation, appropriate holding temperature for PWHT is proved as $750^{\circ}C$ and $765^{\circ}C$ for 1hour per 1 inch nominal weld thickness. Indeed, holding for 1 hour per 1 inch nominal weld thickness was insufficient for PWHT effect when the holding temperature was at $735^{\circ}C$. The microstructure of post-weld heat treated weld metal was determined as tempered-martensite structure.

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A Diagnostic Study of safety education in elementary schools based on PRECEDE Model (PRECEDE 모형을 이용한 일부 초등학교 안전교육의 진단적 연구)

  • 백경원;이명선
    • Korean Journal of Health Education and Promotion
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    • v.18 no.1
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    • pp.35-47
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    • 2001
  • As the complexity of the our environment is further complicated by advancements in industry and increase in vehicle traffic flow, the incidents of injury causing accidents are on the rise. Consequently, there is increasing emphasis on the importance of systematic and continual safety education for injury preventive behaviors. This study investigates safety related problems of elementary school students based on the PRECEDE model, proposed by Green et al.(1980 Green), to comprehensively identify the requirements of school safety education. The identified requirements were used to diagnose the current state of elementary school safety education through the analysis of multidimensional factors. A questionnaire survey was conducted on 594 sixth grade students from randomly selected 4 schools in Seoul to examine their injury preventive behaviors and to determine the educational diagnosis variables that affect it. The duration of the survey was 3 weeks starting from April 12, 1999 to May 8, 1999. A summary of the survey results are presented below; 1. Situations in which accidents have occurred were, in their order of frequency, ‘during play or sports activities within the school grounds’ was most frequent at 59.6%, ‘during play on local streets’ at 49.5%, and ‘traffic accidents’ at 41.6%. 2. Categorization of the injury preventive behavior showed that ‘not playing at high traffic flow locations such as streets and construction sites’ had the higher level of observance, while ‘wearing of helmets and joint protection devices during playing’ was least observed. 3. Considering injury preventive behaviors in relation to educational diagnosis variables indicated, for predisposing factors, lower ‘perception to injury accidents’ (p〈0.001) combined with higher ‘concerns for injury accidents’(p〈0.001), ‘practice of preventive behavior’(p〈0.001), and ‘the level of safety knowledge’(p〈0.001) resulted in significantly higher observance of injury preventive behaviors. For enabling factors, higher ‘perceived level of the school safety education’ (p〈0.001) and ‘availability of safety education resources’(p〈0.01) indicated significantly higher observance of injury preventive behaviors. For the reinforcing factor, frequent exposure to ‘safety education brochure’ (p〈0.01) and ‘audio-visual material for safety education’(p〈0.01) combined with more ‘regional safety education’ (p〈0.01), ‘home safety education’ (p〈0.01), ‘school safety education’(p〈0.001), and, ‘parents’ observance of preventive behaviors' (p〈0.001) showed significantly higher observance of injury preventive behaviors. 4. An analysis of the factors that affect injury preventive behaviors showed that the enabling factor ‘awareness of school safety education’ had the highest correlation with injury preventive behaviors followed by factors, in their order of significance, ‘practice of preventive behavior’, ‘perception to injury accidents’, ‘level of safety knowledge’, ‘parents’ observances of preventive behaviors', and ‘concerns for injury accidents.’

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Study on Analysis for Factors Inducing the Whangryeong Mountain Landslide (황령산 산사태 원인 분석에 대한 연구)

  • 최정찬;백인성
    • The Journal of Engineering Geology
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    • v.12 no.2
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    • pp.137-150
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    • 2002
  • Recently, plane failure mode occurred frequently along the bedding plane having low angle dip about 20 degree when cutting slopes were constructed in sedimentary rock region of the Gyeongsang Basin. Landslide of the Whangryeong Mountain which was occurred at Busan Metropolitan City in 1999 belongs to the category mentioned above. Reconstruction for cutting slope of the Whangryeong Mountain has finished in 2000 and final grade of reconstructed cutting slope is 1:2.0. To analyze slope failure mode for landslide of the Whangryeong Mountain, various analyses were performed such as in-situ investigation and test, drilling, laboratory test, aerial photograph interpretation, X-ray diffraction analysis, and slope stability analysis using Stereographic Projection and Limit Equilibrium methods. As the result, it is identified that tension cracks had been developed one year before the landslide took place. The tension crack semis to be formed by merging several joint sets. It appears that failure blocks broke down along the sliding planes of different layers. Risk of plane failure is conformed as a result of stability analysis using Stereographic Projection and Limit Equilibrium methods in case that greenish gray tuffaceous shales, regared as sliding planes, are weathered. From now on, a detailed investigation is needed for the thin layers which is sensitive to weathering, and stability analysis for this layer is performed at cut slope construction site having similar geological condition.

A Study on the Change of Load Carrying Capacity of High-tension Bolt Joints by Critical Sections (단면결손에 따른 고장력볼트 체결부의 내하력 변화에 관한 연구)

  • Park, Jeong-Ung;Yang, Seung-Hyun;Jang, Seok-In
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.9
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    • pp.2402-2408
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    • 2009
  • This study conducted a static tensile test in order to prevent the lowering of load carrying capacity caused by critical sections made by over bolt holes in the base plate and the cover plate of steel member joints using high-tension bolts. The change of the load carrying capacity of joints was examined by comparison of the maximum load on joint fracture obtained from the tensile test with critical section rate and design strength. According to the results, the rate of decrease in strength was higher when the critical section rate was high, and in particular, decrease in strength was affected much more by critical sections in the base plate than by those in the cover plate. In high-tension bolt joints using over bolt holes for the base plate and the cover plate, load carrying performance was somewhat lower than that in joints using standard bolt holes, but the maximum tensile strength on facture was over 15% higher than design fracture strength. According to the results of this study, the use of over bolt holes in high-tension bolt joints had an insignificant effect on the lowering of load carrying capacity, so the allowance of over bolt holes in the joints of steel members is expected to enhance to the economy and efficiency of the works.

A Study on Cause Analysis and Countermeasures of Chloride Attack of Reinforced Earth Retaining Walls Installed on Bridge Abutment (염해로 인한 교대부 보강토옹벽 손상 원인 분석 연구)

  • Do, Jong-Nam;Kim, Nag-Young;Cho, Nam-Hun;You, Kwang-Ho
    • Journal of the Korean GEO-environmental Society
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    • v.19 no.12
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    • pp.59-64
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    • 2018
  • The damages to the reinforced earth retaining wall are divided into the front wall, foundation, drainage and upper slope. Damage of reinforced earth retaining wall is mainly caused by damage caused by drainage problem in the field. Recently, damage caused by snow removal materials have been occurred. Recently, the amount of snow removal materials used in winter is increasing due to abnormal weather. This chlorides degrades the concrete structure, where the reinforced earth retaining wall was no exception. There has recently been a case in which the front wall of the reinforced earth retaining wall deteriorates due to the chlorides introduced into the back filling portion through the drainage passage. Therefore, in this study, the cause of damages of reinforced earth retaining wall constructed in bridge abutment was analyzed, and an analytical study was conducted on the countermeasure. As a result, it was found that chlorides, which was introduced through the drainage system in the expansion joint of the bridge shift part or the upper structure, is infiltrated into the back part of the reinforced earth retaining wall and damaged. Therefore, it is suggested to improve the drainage system and restored the stiffness of the front wall.