• Structural Engineering and Mechanics
• /
• v.86 no.6
• /
• pp.715-730
• /
• 2023

Broad studies have addressed the issue of structural element damage identification, however, rubber bearing, as a key component of load transmission between the superstructure and substructure, is essential to the operational safety of a bridge, which should be paid more attention to its health condition. However, regarding the limitations of the traditional bearing damage detection methods as well as few studies have been conducted on this topic, in this paper, inspired by the model updating-based structural damage identification, a two-stage bearing damage identification method has been proposed. In the first stage, we deduce a novel bearing damage localization indicator, called element relative MSE, to accurately determine the bearing damage location. In the second one, the prior knowledge of bearing damage localization is combined with sailfish optimization (SFO) to perform the bearing damage estimation. In order to validate the feasibility, a numerical example of a 5-span continuous beam is introduced, also the noise robustness has been investigated. Meanwhile, the effectiveness and engineering applicability are further verified based on an experimental simply supported beam and actual engineering of the I-40 Bridge. The obtained results are good, which indicate that the proposed method is not only suitable for simple structures but also can accurately locate the bearing damage site and identify its severity for complex structure. To summarize, the proposed method provides a good guideline for the issue of bridge bearing detection, which could be used to reduce the difficulty of the traditional bearing failure detection approach, further saving labor costs and economic expenses.

• Korean Journal of Hazardous Materials
• /
• v.2 no.1
• /
• pp.12-17
• /
• 2014

With a rapid growth of domestic industry in korea, now about 25,000 kinds of chemicals are being distributed, and it has been known that just about 15% of them has toxic substances. Recently, South Koreans have an anxiety about the stability and accidents of chemicals because chemical accidents like Gumi hydrofluoric acid accident have occurred. The U.S. has adopted the systems like EPCRA (Emergency Planning and Community Right-to-Know Act), TRI (Toxic Release Inventory) and TSCA (Toxic Substances Control Act), and is also managing the hazardous chemicals by providing the information about them to its people and site workers. Japan's Ministry of Health, Labor and Welfare also has adopted J-CHECK system and is implementing it to let Japanese people know the information of safety of chemicals about REACH. However, the Korean government has a difficult situation to mediate the different idea with the Korean industry to make lower statute of Pre-legislation registration & evaluation of chemicals that will be implemented and Chemical Material Control Association that is being implemented. Especially city and country areas located in the industrial areas need political improvement focusing on vulnerable area through the check about current situation of hazardous chemicals of jurisdiction and management method, but the information about the management situation of small scale work places is insufficient. Therefore this study set up the urgent management area in Ansan Smart Hub through NFPA code according to the types of accident and dander characteristics of each chemical being used in the companies that have less than 50 workers and deal with chemicals located in Ansan Smart Hub in Gyeonggi-do.

• Journal of the Korean Geotechnical Society
• /
• v.31 no.5
• /
• pp.5-21
• /
• 2015

An energy pile is a novel type of ground heat exchangers (GHEX's) which sets up heat exchange pipes inside a pile foundation, and allows to circulate a working fluid through the pipe for exchanging thermal energy with the surrounding ground stratum. Using existing foundation structure, the energy pile can function not only as a structural foundation but also as a GHEX. In this paper, six full-scale energy piles were constructed in a test bed with various configurations of the heat exchange pipe inside large-diameter cast-in-place piles, that is, three parallel U-type heat exchangers (5, 8 and 10 pairs), two coil type heat exchangers (with a 500 mm and 200 mm pitch), and one S-type heat exchanger. During constructing the energy piles, the constructability of each energy pile was evaluated with consideration of the installation time, the number of workers and any difficulty for installing. In order to evaluate the thermal performance of energy piles, the thermal performance tests were carried out by applying intermittent (8 hours operating-16 hours pause) artificial cooling operation to simulate a cooling load for commercial buildings. Through the thermal performance tests, the heat exchange rates of the six energy piles were evaluated in terms of the heat exchange amount normalized with the length of energy pile and/or the length of heat exchange pipe. Finally, the economic feasibility of energy pile was evaluated according to the various types of heat exchange pipe by calculating demanded expenses per 1 W/m based on the thermal performance test results along with the market value of heat exchange pipes and labor cost.

• Steel and Composite Structures
• /
• v.21 no.1
• /
• pp.73-91
• /
• 2016

The use of box columns has been increased due to the rigidity in rigid orthogonal moment resisting frames. On the other hand, the installation and welding of necessary horizontal continuity plates inside the columns are both labor-consuming and costly tasks. Accordingly, in this paper, a new beam-to-box column connection by trapezoidal external stiffeners and horizontal bar mats is presented to provide seismic parameters. The proposed connection consists of eight external stiffeners in the level of beam flanges and five horizontal bar mats in Concrete Filled Tube (CFT) columns. The new connection effectively alleviates the stress concentration and moves the plastic hinge away from the column face by horizontal external stiffeners. In addition, the result shows that proposed connection has provided the required strength and rigidity of connection, so that the increased strength, 8.08% and rigidity, 3.01% are compared to connection with internal continuity plates, also the results indicate that this connection can offer appropriate ductility and energy dissipation capacity for its potential application in moment resisting frames in seismic region. As a result, the proposed connection can be a good alternative for connection with continuity plates.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.15 no.5
• /
• pp.1-7
• /
• 2001

Factors which affect largely the economics of lighting system, are initial installation costs, maintenance costs, energy costs as so on. In these costs, maintenance cost, lamp replacement labor cost, luminaire cleaning cost et al. so the economics of lighting system are evaluated different by maintenance planning. It is important to evaluate which lighting system would be economically advantageous in a initial design. In this study, the importance of maintenance factor is verified by the evaluations of the economics of lighting systems while maintenance factor is varied composition factors in ZCM which is used to calculate the average illuminance.

• Current Research on Agriculture and Life Sciences
• /
• v.3
• /
• pp.55-61
• /
• 1985

In an attempt to compare the mash and pelleting costs, individual production costs of eash mash and pelleting are analyzed. For the analysis, Park's model (1982) are used. According to the results of the analysis, the following conclusions are made. 1. Total energy cost for pelleting is 4 times higher than that for mash feed production. 2. Labor cost for pelleting is 20 % higher than that of mash feed. 3. Capital requirements for pelleting feed mill is approximately 20 % higher than that for mash feed mill when feed mill size is 200 ton/day. 4. Total production cost for pelleting is from 30 % to 50 % higher than that for mash feed when mill size ranges from 100 ton/day to 400 ton/day.

• Asian Journal of Business Environment
• /
• v.10 no.2
• /
• pp.17-21
• /
• 2020

Purpose: This paper explores diverse issues related to the problem of women's unpaid domestic care work, and as a factor of gender inequality in their professional practice. Research Design: This article concentrated only on the analysis of secondary data available on the topic along with observation of facts in Kazakhstan based on diverse sources. In current conditions, the problem of women's unpaid domestic care work, and consequently, the lack of enough time and energy for professional employment. Distinguish domestic work vs. job/career/occupation, self-fulfillment, education, and leisure has a significant impact on women's life satisfaction. Data, and Methodology: This article focuses only on secondary data available in different sources from which the researchers procures comprehensive data and information. Results and conclusion: A family policy that aims to promote combining maternity, and domestic work with paid employment is an effective way to increase the proportion of working mothers/women. It is crucial to not only proportionally distribute the household responsibilities in the family but also to form an effective mechanism of state support for women through the development of the social services sector, as well as the adoption of a system-wide approach to gender equality.

• Journal of Haehwa Medicine
• /
• v.8 no.2
• /
• pp.133-152
• /
• 2000

1. At the Menstruation Period, the uterus is easy to be invaded by a toxin because of its patency. Take cleanliness and hygiene into consideration. 2. At the Menstruation Period, much attention must be paid at the regulation of coldness and heat to harmonize the Menstruation. 3. At the Menstruation Period, excessive exercise must be avoided. Appropriate labor can help the circulation of vital energy & blood and reinforce the immunity of body. 4. The nourishing, plain, warming, digestible food is good at the Menstruation Period. Hot, stenched, stimulating food must be avoided and nuts & water fruit must not be overeaten. 5. At the Menstruation Period, sharpness & excessiveness of emotion must be avoided and a comfortable mood must be maintained. Especially premenstrual or postmenstrual period, peaceful spirit and sufficient sleep must be kept. 6. Women generally feel uncomfortable at the Menstruation Period, but it disappears spontaneously after menstruation. Don't take an overdose of medicine because it can disturb the normal condition.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.3
• /
• pp.167-174
• /
• 2008

Cost related to building equipment accounts for about 85% of the life cycle cost of buildings. Therefore proper selection of air-conditioning system is important for reducing the overall cost of buildings. In this study, medium capacity EHP and GHP for air-conditioning a building with a floor area of 1,200 $m^2$ are compared economically. To consider all the factors of initial and operation costs effectively, an annual equal payment method is proposed. For the initial cost, cost of equipment, construction, installation, electric facility, financial subsidy and tax cut is considered. Cost of basic electricity, energy(electricity and gas), space charge, labor, insurance and repair is considered for the operation cost. Under the assumptions made in this study, overall cost of EHP is less than that of GHP, but this is not absolute and different outcome may result if different assumptions are made. This study is useful for those who are interested in choosing an air-conditioning system that costs less for mid-size buildings with simple calculations.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1998.03a
• /
• pp.138-143
• /
• 1998

The continuous casting process has been adopted increasingly in recent years to save both energy and labor. It has experienced a rapid development in the production of semi-finished steel products, replacing the conventional route of ingot casting plus rolling. To achieve this good merit, however, more studies about a heat transfer mechanism between roll and slab are needed. So this paper shows the results of the deformation behavior of steel cast slabs, which are about the solidification and heat transfer. This study is used to prevent internal cracks of a slab in a bending and unbending zone. The value of moving strand shell bulging between two supporting rollers under ferrostatic pressure and slab-self weight has been computed in terms of creep and elastic-plasticity. The high strand distributions in solidified shell undergoes a series of bulging are calculated with boundary condition a very closed to continuous steel cast slabs productions.