• Smart Structures and Systems
• /
• v.20 no.5
• /
• pp.549-562
• /
• 2017

The US railroad network carries 40% of the nation's total freight. Railroad bridges are the most critical part of the network infrastructure and, therefore, must be properly maintained for the operational safety. Railroad managers inspect bridges by measuring displacements under train crossing events to assess their structural condition and prioritize bridge management and safety decisions accordingly. The displacement of a railroad bridge under train crossings is one parameter of interest to railroad bridge owners, as it quantifies a bridge's ability to perform safely and addresses its serviceability. Railroad bridges with poor track conditions will have amplified displacements under heavy loads due to impacts between the wheels and rail joints. Under these circumstances, vehicle-track-bridge interactions could cause excessive bridge displacements, and hence, unsafe train crossings. If displacements during train crossings could be measured objectively, owners could repair or replace less safe bridges first. However, data on bridge displacements is difficult to collect in the field as a fixed point of reference is required for measurement. Accelerations can be used to estimate dynamic displacements, but to date, the pseudo-static displacements cannot be measured using reference-free sensors. This study proposes a method to estimate total transverse displacements of a railroad bridge under live train loads using acceleration and tilt data at the top of the exterior pile bent of a standard timber trestle, where train derailment due to excessive lateral movement is the main concern. Researchers used real bridge transverse displacement data under train traffic from varying bridge serviceability levels. This study explores the design of a new bridge deck-pier experimental model that simulates the vibrations of railroad bridges under traffic using a shake table for the input of train crossing data collected from the field into a laboratory model of a standard timber railroad pile bent. Reference-free sensors measured both the inclination angle and accelerations of the pile cap. Various readings are used to estimate the total displacements of the bridge using data filtering. The estimated displacements are then compared to the true responses of the model measured with displacement sensors. An average peak error of 10% and a root mean square error average of 5% resulted, concluding that this method can cost-effectively measure the total displacement of railroad bridges without a fixed reference.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.40 no.2
• /
• pp.1-9
• /
• 2003

We develop an experimental system to inspect a metal mask and, in this paper, introduce its inspection algorithm. This system is composed of an ASC(Area Scan Camera) and a belt type xy-table. The whole area of the metal mask is divided into several inspection blocks. The area of each block is equal to FOV(Field of View). For each block, the camera image is compared to the reference image. The reference image is made by gerber file. The rotation angle of the metal mask is calculated through the linear equation that is substituted two end points of horizontal boundary of a specific hole in a camera image. To calculate the position error caused by the belt type xy-table, HT(Hough-Transform) using distances among the holes in two images is used. The center of the reference image is moved as much as the calculated Position error to be coincided with the camera image. The information of holes in each image, such as centroid, size, width and height, are calculated through labeling. Whether a holes is mado correctly by laser machine or not, is judged by comparing the centroid and the size of hole in each image. Finally, we build the experimental system and apply this algorithm.

• East Asian Journal of Business Economics (EAJBE)
• /
• v.5 no.4
• /
• pp.39-49
• /
• 2017

Purpose - This study is to propose a creative idea for constant business growth and development by examining characteristics of business outcomes by phase, which are "growth" and "erosion and stagnation," respectively. Research design, data, methodology - It is necessary to identify an occurrence of crisis and its diffusion with a dynamic model in order to identify a success and failure of businesses in an organic way, not on a binary structure. The static perspective is to understand a crisis as a simply one-time event or as a linear causation. Thus, it has a limited understanding of the overall situation and has limits to investigating a foundational cause and developing long-term countermeasures. On the contrary, the dynamic perspective is to understand the crisis as circulation process of the overall system. Thus, it divides elements of the crisis as external and internal ones to understand it as the causal relationship of each element. Results - During the growth period of Burger King, the company promoted its brand very successfully with aggressive and creative marketing activities. However, due to the founder's disposal of management rights and the following changes in the management, the company had no choice but to lose focus on its business philosophy and brand management, and eventually it had to face the big crisis (resonance) which was delisting from the stock market because of the external threat; well-being trend. However, Burger King resumed lifting on the stock exchange by making great efforts to clearly identify the current issues and seek solutions. Under the spirit of "perseverance" and its slogan "Have it your way" the company is now going head to head with McDonald's in the North American region and emerging countries. Conclusions - Then, what is the most crucial factor in the success and failure of businesses? Answers may vary, however, as learned from the case study of Burger King, corporations should inspect the present and focus on developing a long-term strategy for the future and actively fulfill the actions. McDonald's may not be able to innovate by itself in the future as it may become routinized to the growth. There will be chances of winning if we change conditions of individuals or organizations to an organic system in terms of being creative. There is a hopeful message here that an individual or small business may have more advantages in the era of the idea and innovation.

• Korean Journal of Environment and Ecology
• /
• v.24 no.6
• /
• pp.735-743
• /
• 2010

In order to inspect growth responses of Fraxinus rhynchophylla Hance, Koelreuteria paniculata Laxmann, Quercus acutissima Carruther and Ulmus parvifolia Jacquin to NaCl treatment, NaCl solution was treated for four months with 0, 25, 50, 100 and 200 mM concentrations, then survival rate, change of relative growth rate, weight, dry weight and pigment content of leaf were investigated. According to NaCl treatment, pH and EC (electrical conductivity) of soil increased, and growth rates of four tree species fell apparently as treatment time became longer. U. parvifolia had the highest survival rate with 15% in the 200mM treatment, and the other three species withered in the treatment. Relative growth rate, weight and dry weight decreased when NaCl treatment time grew longer. The total chlorophyll declined after it rose to 60 days, and the total chlorophyll and carotenoid of the all species according to NaCl treatment did not change very much. With the result from anlayzing growth responses of four tree species to oxidative stress which occurs during NaCl treatment, U. parvifolia has the highest tolerance, followed by K. paniculata, F. rhynchophylla and Q. acutissima.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.7
• /
• pp.230-238
• /
• 2014

In this paper, we propose the possible way of accurate analysis and examination of ITO sensor to discriminate whether mutual capacitance ITO sensor is defective by using mutual capacitance of data in each node which consists of electrodes inside of ITO sensor. We have analyzed the structure characteristic of mutual capacitance ITO sensor which is used as an input device for not only small size electronics like mobile phone and tablets but also big size electronics and designed the circuit to inspect ITO sensor using touch screen panel IC. Set a variable related with mutual capacitance of charge and discharge and Implement to find and analyze accurate position when defect is made through the data from each node of ITO sensor. First, we can set a yield effective range through the first experiment data of mutual capacitance ITO sensor and by using the data of each node of ITO sensor which is the result from the second experiment, we can verify accuracy and effectiveness of effective range from the first experiment as a sample which is used in this experiment.

• Journal of the Society of Naval Architects of Korea
• /
• v.36 no.4
• /
• pp.137-146
• /
• 1999

Inspection becomes to be important in the safety of structure and economical viewpoint, because structural damage accompanies lots of economical cost and social problems. Especially ship structure is composed of a lot of members and it is impossible to inspect all members continuously. The purpose of this paper is to get optimal inspection plan containing inspection time and method. Crack is one of major modes on the structural failure and can lead to collapse of structure. In this paper, the deteriorating process, which contains inspection to detect the crack before the propagation to large crack, is idealized as Markov chain model. Genetic algorithm is also used to accomplish the optimization of inspection plan. Especially, the probabilistic characteristics of cracks are changed, because ship is operating in corrosive environments and the scantling of structural members is reduced due to corrosion. Non-stationary Markov chain model is used to represent the process of corrosion in structural members. In this paper, the characteristics of indivisual inspection plan are compared by numerical examples for the change of corrosion rate, the cost due to scheduled system down and target failure probability. From the numerical example, it can be seen that the improvement of fatigue life for the members with short fatigue life is the most effective way in order to reduce total maintenance cost.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.18 no.2
• /
• pp.111-120
• /
• 2000

Water, waste, electric and gas facilities are urban based facilities that needed in our life and are often located in underground. Therefore, underground facilities are more difficult to manage efficiently than ground facilities. It is needed to carry out survey/probe into underground facilities and to build database in order to prevent city-misfortunes being occurred because of negligent management and in order to minimize budget-waste and a traffic jam according to repetition of road excavation constructions. Also, the development of application system is required to manage efficiently underground facility. Chonju city has launched underground water supply facility computerizing project as a part of National Geographic Information System project until December 1998 and executed survey/probe into 402.89 km water supply that is 80 mm up inside central town area 39.6 $km^2$. Also, chonju city built database into 537 km water supply that is 80 mm below based on water supply card without other survey/probe works. Also, existing work process each department is changed into GIS applied work process and underground water supply facility management system is developed by its work process basis. Water supply underground facility management system that is developed is composed of sub-system like base-map management, water supply inspect, water supply management and water supply inquiry, construction work management, administration management and map management. This research presents the procedure and method of underground water supply facility survey/probe and problem being occurred during survey/probe procedure and also show the functions of each sub-systems composing underground water supply facility management system.

• Korean Journal of Construction Engineering and Management
• /
• v.15 no.2
• /
• pp.62-70
• /
• 2014

An apartment house, a private facility, is a house built for many persons to live independently in a building. An apartment house is a building where life damage can happen most in case of a safety accident due to insufficient inspections. However, formal inspections are being realized due to awareness shortage of managing bodies about safety inspection and low-price order-receiving of diagnosing enterprises via the lowest bidding method. This is because it is judged that remarkable costs are inputted in repairs and reinforcement such as maintenance of a structure and that there is a large possibility of human damage in case of a safety accident in a structure. So, this paper aims to derive the points to improve in the current criterion to execute an efficient detailed inspection. As its method, the design price and execution price situation of 66 buildings inspected in detail for recent 3 years for the class 2 facilities in Gwangju Metropolitan City and Jeonranam-do are examined and analyzed. The state2 object buildings to inspect are selected through this. And this paper aims to present the points to improve through the analysis of current problems by evaluating the detailed inspection report and the detailed inspection execution price calculation criterion for the selected 10 apartment houses.

• 대한공업교육학회지
• /
• v.41 no.1
• /
• pp.1-21
• /
• 2016

The purpose of this study is to analyze job of die and mold makers for apprenticeship education of specialized high school using DACUM method. The contents of this study were to identify the duties, specific tasks performed and the level of importance, difficulty, frequency and entry level on each task. This study also make out a DACUM chart of die and mold makers for apprenticeship education of specialized high school. The DACUM committee, which consisted of one facilitator, nine die and mold experts, one recorder and one coordinator, was established to conduct DACUM. The conclusions are as follows; First, this study defines a die and mold makers as 'a person who make it possible to manufacture/assemble/inspect die and mold parts using various machine tool'. Second, duties in job of die and mold makers for apprenticeship education were total 12 and total tasks in job of die and mold makers for apprenticeship education were 86. Third, this study determine the level of importance, difficulty, frequency and entry level about each task. Finally, this study make out a DACUM chart of die and mold makers for apprenticeship education of specialized high school based on the results of DACUM job analysis. And knowledge, skills, tools, and positive behaviors, future trends/concerns about die and mold makers for apprenticeship education of specialized high school were presented.

• 대한공업교육학회지
• /
• v.44 no.2
• /
• pp.86-103
• /
• 2019

The purpose of this study is to provide basic data on the development of education and training programs for training 'mechanical facilities maintenance manager'. To this end, the DACUM technique was used for job analysis and education and training programs were developed through expert consultation meetings. The job analysis was based on the 10-member DACUM Committee to derive the job definition, job model, job description, and task description of the 'mechanical facilities maintenance manager'. The main findings are as follows. First, the 'mechanical facilities maintenance manager' was defined as those who operate, inspect, diagnose, and repair mechanical facilities to provide the best performance and efficient operation management, provide a safe and pleasant environment, and perform energy saving and facility life extension tasks. Second, the duties of the 'mechanical facilities maintenance manager' analyzed in the job model consist of the comprehensive plan for operation of mechanical facilities, energy management of mechanical facilities, operation management of mechanical facilities, maintenance of mechanical facilities, safety environment management of mechanical facilities, and customer support management of mechanical facilities. Considering the nature and content of the duties, 4 to 11 tasks per duty were derived and a total of 33 tasks were presented as job model. Third, the curriculum for the 'mechanical facilities maintenance manager' was set up in two courses: Practice I for Mechanical Facilities Maintenance and Practice II for Mechanical Facilities Maintenance. Considerations and policy suggestions were presented when applying and implementing education and training programs based on the results of the research.