PURPOSES : The purpose of this study is to investigate the stresses of the middle slab in a double-deck tunnel owing to the slab lift to replace the underlying elastic pads during maintenance workMETHODS: The middle slab was divided into three different sections: typical section, expansion joint section, and emergency passageway section. Finite element analysis models of these three sections of middle slab were developed, and the stress distribution and maximum stresses were obtained using the models when the middle slab was lifted to replace the underlying elastic pads. Various slab lifting methods were examined in this study such as one-, two-, and multiple-point lifts, distributed lifts, and one or both slab side edge lifts.RESULTS: When the slab side edge is lifted, the longitudinal stresses of the slab are almost the same as the principal stresses. This implies that the governing stresses are the longitudinal stresses. The maximum stresses with both-edge lifts are generally smaller than those with one-edge lifts at all three sections of middle slab.CONCLUSIONS: If the middle slab in a double-deck tunnel is lifted for maintenance, the slab should be lifted at multiple points along the longitudinal direction to reduce the tensile stresses.

본 논문은 미얼 래더맨 유켈리스의 유지관리예술에 관한 연구이다. 1969년 유켈리스는 ‘유지관리예술 전시계획서’ 선언문을 통해 여자들이 집안일을 떠맡는 것에 반박했 다. 이 선언서는 페미니즘 미술성향으로 쓰여 졌으며, 유켈리스는 의존이라는 불변의 제도에 갇힌 가정주부 이미지를 바꾸고자 시도하였다. 당시 첫째 아이를 임신했던 그녀는 사회적, 정치적 변화에 대항하는 한편 생물학적, 심리적 변화를 겪고 있었고, 이런 경험은 예술에 대한 그녀의 태도에 직접적인 영향을 미쳤다. 다시 말해서 유켈리스는 예술과 생활을 양립시킬 수 있는지 의문을 가졌고, ‘유지관리예술가’가 되어 가정주부와 예술가의 전형을 재해석하고자 했다. ‘우리의 일상이 돌아가도록 만드는 행위(performance)’인 ‘유지관리예술’은, 전통적으로 열등한 노동으로 여겨지는 여성의 가사노동, 즉 요리와 청소, 육아, 쇼핑(장보기) 등의 일을 ‘유지관리(maintenance)’ 양식의 작업이라고 선언하였다. 이러한 유지관리 양식은 ‘발달(development)’ 양식의 작업과는 대립되는 것으로서 정의한다. 즉 작가는 유지 관리예술 전시계획서에서 ‘발달’과 ‘유지관리’를 두 개의 기본적인 체계로 구분한다. 즉, 발달은 순수하게 개인적인 창조, 새로운 것, 변화, 발전, 전진, 흥분 등이며, 유지관리는 순수하게 개인적인 창조물에서 먼지를 털어내는 것, 새로운 것을 보존하는 것, 변화를 인정하고, 발전을 보호한다, 전진을 방어하고 연장한다, 흥분을 새롭게 한다 등으로 해석한다. 그리고 ‘유지관리’의 작업도 발달의 양식과 동등한 지위를 얻어내야 함을 주장 하였다. 이러한 유켈리스의 작품 성향은 마르셀 뒤샹의 레디메이드와 같이 일반 사물이 예술적 공간에서 기능을 잃고 변형됨으로써 나타나는 경계의 와해와 영역의 파괴라는 점에서 아방가르드의 성격이 있다. 뒤샹은 미술에 대한 기존의 관념, 작품의 인습적인 제작, 평가, 수용, 유용의 모든 과정에 도전했다. 작품과 작가의 범주, 미에 대한 관객의 기대, 작품의 서사 체계, 이성적 해석 등을 무력화하기 위해 우연이라는 방식을 선택하고 미의 객관적 가능성을 시도했다. 뒤샹의 방식대로, 유켈리스의 작품은 가사생활에서의 문제점들과 관련된 레디메이드를 지속하고 확장시켜나갔다. 그녀의 작품들이 담아내고자 하는 내용은 명백히 일상적인 가사노동과 관련이 있었고, 이는 예술활동의 대상에 대한 개념주의적인 태도로써 레디메이드의 본래의 도전도 계속적으로 이어나갔다. 그녀는 또한 초기부터 제도비판에 대한 옹호자였으며, 하트퍼스에서의 퍼포먼스를 통해 박물관의 권력구조가 어떻게 전복되는가를 분명히 보여주었다. 유지관리를 위한 노동은 예술처럼 흥미롭거나 전위적인 것이 아닐지 모르지만, 삶에 있어서 필수적인 것 이다. 유켈리스의 유지관리 작업은 행동주의와 학문적 관점에 대한 접근을 통해 페미니즘적인 자기 정체성과 공동체 사회와의 연관성을 명백하게 드러내면서 다양하게 확장하게 한다.

As a system complexity increases and technology innovation progresses rapidly, it tends to lease a system rather than own one. This paper deals with a decision-making model to determine the preventive maintenance strategy for leased equipment. Various maintenance options are presented and formulated via the non-homogeneous Poisson process. During the lease period, the preventive maintenance strategy that minimizes the total cost among the presented maintenance options is selected. A numerical example is provided to illustrate the proposed model.

Despite the importance of city parks and the changes in perception and involvement of users, park management budgets are constantly being contracted. Accordingly, the problems on maintenance control of neighborhood parks are now being realized, and studies on management improvement are required. This study is focused on the operation conditions and user satisfaction of the neighborhood parks in Daegu. Based on the analysis, efficient park management measures are suggested and baseline data are provided for subsequent studies. Targeting the neighborhood parks that the primary local government of Daegu is directly managing, the maintenance management costs were compared for a period of five years, and the average budget per unit area was calculated based on the completed neighborhood parks. Eight neighborhood parks were selected, including Dalseo-gu, whose average budget per unit area is the highest, and Buk-gu, where it is the lowest. Further, field and user attitude surveys were carried out. From the results of the field survey, the administrative status on neighborhood parks of Dalseo-gu and Buk-gu showed a satisfactory level, beyond the average one. The management score on neighborhood parks of Dalseo-gu appeared higher than that in Buk-gu. According to the results of the attitude survey, which targeted the users of these parks, the main users utilizing the neighborhood parks were nearby residents, and their share of responses indicating that they go to the park on foot was the highest, 74.6%. Regarding the importance and satisfaction on the elements that compose the parks, classified in 7 point-scaled criteria, the favorable answers were those over 5 points. According to the levels of user satisfaction calculated based on this method, Buk-gu ranked higher than Dalseo-gu. Based on the expected level of service and the evaluation of how they are perceived, through an IPA analysis, the park facilities were divided into to four areas. As a result, it emerged that continuous interest and intensive management of the properties would be required.

This paper presents another maintenance policy for a group of units under finite operating horizon. A group of identical units are subject to random failures. Group maintenances are performed to all units together at specified intervals, and the failed units during operation are remained idle until the next group maintenance set-up. Unlike the traditional assumption of infinite operating horizon, we adopt the assumption of the finite operating horizon which reflect the rapid industrial advance and short life cycle of modern times. The units are under operation until the end of the operating horizon. Further, the operation of units are extended to the first group maintenance time after the end of the horizon. The total cost under the proposed maintenance policy is derived. The optimal group maintenance interval and the expected number of group maintenances during the horizon are found. It is shown that the proposed policy is better than the classical group maintenance policy in terms of total cost over the operating horizon. Numerical examples are presented for illustrations.

This paper suggests a specific model that could efficiently improve the interaction and the interface between MES(Manufacturing Execution System) server and POP(Point of Production) terminal through electronic document server and electronic pen, bluetooth receiver and form paper in disassembly and process inspection works. The proposed model shows that the new method by electronic document automation system can more efficiently perform to reduce processing time for maintenance work, compared with the current approach by handwritten processing system. It is noted in case of the method by electronic document automation system that the effects of proposed model are as follows; (a) While the processing time per equipment for maintenance by the current method was 300 minutes, the processing time by the new method was 50 minutes. (b) While the processing error ratio by the current method was 20%, the error ratio by the new method was 1%.

The study seeks to cooperate with the investigation of a fire investigation based on public-private partnership. Fire protection systems provide a wide variety of viewpoints from the perspectives of design, construction, management, maintenance, maintenance and maintenance systems at a particular point in time, construction, management, and maintenance systems. What is controversial is that there are illegal activities such as illegal activities of the Patent Office, misconduct of construction work and unreasonable construction of construction works.As a theoretical framework, the present study identified the four key elements of a successful disaster response system : responsiveness, control, professionalism, and bias.

군사용으로 먼저 개발되어 온 드론은 요소기술의 급격한 발전을 통해 민간 분야로 확대되면서 최근 다양한 산업분야에 활용되 고 있다. 이러한 시대적 흐름에 따라, 조선해양 산업계에서도 유지보수 및 점검용으로 드론의 활용이 유럽을 중심으로 본격화되고 있다. 이와 관련하여, 본 논문에서는 조선해양 분야에 적합한 드론의 기술개발을 위해 선박 및 해양플랜트의 유지보수 점검의 현상태를 진단함 으로써 드론 기술개발의 방향성을 제시한다. 즉, 조선해양용 드론이 이미 상용화 된 선진국의 기술력을 살펴보고, 조선해양 산업계에서 드론시대를 대비하여 해결해야 할 기술적 과제들을 소개한다. 또한, 이러한 드론의 시장성장 가능성을 전망함으로써 기술개발의 추진력 을 제공하고자 한다.

This research focuses on the condition of the coveralls that automobile maintenance workers wear. The objective of this survey is to conduct a thorough analysis on the quality of the coveralls and put forth suggestions for improving their quality. The research data were collected through interviews and the results are as follows. The participants in this research engage in a variety of types of maintenance work including oil changes and overall system checks and they usually wear extra-large-sized coveralls. The coveralls are generally worn during the winter for warmth and the company handles all purchasing and maintenance of the work clothes. Participants mentioned that certain parts of the clothes where they bend and stretch are cumbersome and areas around the knees and arms become easily tainted. They have also reported that although the coveralls are necessary, they are for the most part dissatisfied when it comes to the materials, design, and color. The participants have suggested that new coveralls would help to increase their work efficiency. As a result, it is concluded that the coveralls require much more development to meet the workers’ needs and improvements need to be made on the functionality, aesthetics, and symbolic aspects of the design.

This research focuses on the condition of the coveralls that automobile maintenance workers wear. The objective of this survey is to conduct a thorough analysis on the quality of the coveralls and put forth suggestions for improving their quality. The research data were collected through interviews and the results are as follows. The participants in this research engage in a variety of types of maintenance work including oil changes and overall system checks and they usually wear extra-large-sized coveralls. The coveralls are generally worn during the winter for warmth and the company handles all purchasing and maintenance of the work clothes. Participants mentioned that certain parts of the clothes where they bend and stretch are cumbersome and areas around the knees and arms become easily tainted. They have also reported that although the coveralls are necessary, they are for the most part dissatisfied when it comes to the materials, design, and color. The participants have suggested that new coveralls would help to increase their work efficiency. As a result, it is concluded that the coveralls require much more development to meet the workers’ needs and improvements need to be made on the functionality, aesthetics, and symbolic aspects of the design.

본 연구는 철도 시설의 선로를 대상으로 하여, Building Information Modeling(BIM)을 위한 데이터 모델인 Industry Foundation Classes(IFC)의 유지관리관점의 부분집합인 Construction Operations Building information exchange(COBie)를 통해 철도 시설물 유지관리문서를 생성할 수 있는 방안을 제시하였다. 철도 선로유지관리 문서 생성에 필요한 항목을 정의 하기 위해 국토교통부의 선로유지관리지침 분석을 수행하였고, 이를 COBie 스프레드시트에서 참조하기 위한 방식을 정의하 였다. 철도 시설물 선로의 유지관리정보 항목을 반영한 정보모델 생성을 위하여 IFC 프레임워크 내의 사용자 정의 속성집합 을 활용하였으며, 이를 통해 IFC에서 지원하지 않는 철도 선로에 대한 추가 항목을 생성하였다. BIM 소프트웨어를 통해 추 가적으로 생성한 사용자 정의 속성집합을 반영한 IFC 기반의 정보모델을 생성하였고, 이를 정의된 참조방식에 따라 선로 유 지관리 정보항목을 COBie 스프레드시트에 전달하고 그 결과를 확인하였다. 이를 통해 IFC 기반의 As-built 모델로부터 COBie 스프레드시트로 정보를 전달함으로써 철도 시설물 유지관리업무를 위해 필요한 문서 생성에 활용할 수 있음을 확인 하였다.

This study was conducted to evaluate the protein requirement for maintenance of fattening Korean black goat (Capra hircus coreanae). Six male goats with average initial body weight (BW) of 31.78±4.54kg and an average age of 8 months were used in this study. The experiment had a replicated duplicated 3×3 Latin square design for balancing carryover effects. In the course of the experiment, each of Black goats were fed three diets that were formulated to contain T1 (13%), T2 (16%) and T3 (19%) levels of crude protein (CP). A 14-day diet adjustment period was followed by a 5-day collection period. Dry matter intake (DMI) of groups fed diets with T2 was 966.67g/d which was higher than group fed diets with T1 and T3 were 925.14g/d and 936.08g/d each. Average daily gains (ADG) of black goats were the highest in T2(167.13g/d) But, there was no significant difference. Dietary protein levels affected the apparent digestibility of CP (p<0.05). A significant difference was found in CP intake among treatments and goats receiving T3, T2, and T1 recorded 181.23, 154.57, and 128.78g CP/d, respectively. This was excepted because CP intake is proportional to CP content of diet, which from highest to lowest was as follows: T3 (19%) > T2 (16%) > T1 (13%). Intercept of the regression equation between CP intake and CP balance indicated that maintenance CP requirement was 1.63g/BW0.75.

PURPOSES: Pavement Management System contains the data that describe the condition of the road. Under limited budget, the data can be utilized for efficient plans. The objective of this research is to develop a mixed integer program model that maximizes remaining durable years (or Lane-Kilometer-Years) in road maintenance planning. METHODS: An optimization model based on a mixed integer program is developed. The model selects a cluster of sectors that are adjacent to each other according to the road condition. The model also considers constraints required by the Seoul Metropolitan Facilities Management Corporation. They select two lanes at most not to block the traffic and limit the number of sectors for one-time construction to finish the work in given time. We incorporate variable cost constraints. As the model selects more sectors, the unit cost of the construction becomes smaller. The optimal choice of the number of sectors is implemented using piecewise linear constraints. RESULTS: Data (SPI) collected from Pavement Management System managed by Seoul Metropolitan City are fed into the model. Based on the data and the model, the optimal maintenance plans are established. Some of the optimal plans cannot be generated directly in existing heuristic approach or by human intuition. CONCLUSIONS: The mathematical model using actual data generates the optimal maintenance plans.

The competition of maintenance services in the offshore wind industry is continually increasing. The quality of the services acts as the distinguishing feature in the industry. Furthermore, there are public standards, which lead to the permanent necessity to offer further education and training programs for employees. To meet the requirements for further training in the specific field of application within the offshore wind industry, a gamified e-learning application has been developed and is introduced in this paper. It consists of a complete solution, which contains the automated analysis of service protocols to identify qualification needs, the involvement of service technicians in the generation of learning materials, the preparation, transmission as well as the further development of those materials in accordance with the principles of e-learning. Finally, the solution contains a gamified mobile application for qualification, which is designed to meet the individual learning needs of the service technicians. This concept paper follows a problem-centred approach. Based on the current state of technology and research, the problem and motivation are identified and the urgency is verified. Furthermore, a detailed specification of the solution and a first implementation approach is presented.

For the purpose of economic growth in the nineteenth century, social infrastructures have been rapidly aging since the 21st century, Currently, many of the existing infrastructure has been aged, and many national costs have been spent on safety Inspection and maintenance. It is expected that more maintenance will be costly in the future, and maintenance cost can be expected to be reduced due to safety inspection and repair and reinforcement measures in a timely manner. The measures provided in the national and international safety inspection and maintenance manual reduce the efficiency of the work by repeating document work. In addition, due to lack of information sharing among practitioners performing inspection and maintenance, it is considered that incomplete work or incurring additional costs will lead to a large national loss. Building Information Modeling (BIM) can manage all the information generated during the whole life cycle of social infrastructures. Domestic institutions are increasing the use of BIM, and the Public Procurement Service is obliged to design BIM. We expect to increase the work efficiency of practitioners by reducing repetitive document work using BIM, It will make the integrated management information enable bi-directional communication among practitioners. First of all, building a library of social infrastructures and standardizing the information classification system and procedures for BIM application should be essential. As a result, standardization studies on standard information classification system and procedures based on representative bridges among social infrastructures were conducted.