• Journal of Energy Engineering
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• v.26 no.4
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• pp.127-142
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• 2017

After individual consumption tax on bituminous coal has been imposed by Korean government after 2014 Jul, we analyse the influence of tax and conclude that the consumption of high calorie coal has been increased and that of low/middle calorie coal has been decreased. And also, the average calorie of coal consumption has been increased and the more fuel cost happens on account of the average calorie increase. Those effects have been caused by the current tax imposition system which does not reflect the bituminous coal trait. The motivation of oversea resource development and the effort of coal blending skill have been decreased because of the current tax policy. We suggest 2 ways of the tax policy improvement system[1. tax imposition system in proportion to 5,000kcal/kg, 2. 15 stages(1 stage : 200kcal/kg) segmentation tax imposition system equal to the tax/(5,000kcal/kg)] to increase the current tax amount, to prevent the coal consumption distortion and to remove the further fuel cost.

• Journal of Construction Engineering and Project Management
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• v.2 no.2
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• pp.18-27
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• 2012

Despite the rapid development in the construction industry due to the changing new technologies, many projects still fail to meet target deadlines. Shortage in manpower and skilled laborers is one of the main reasons for such delays. Markets with high economic growth and economic expansion (such as Gulf Countries in the Middle East) may have pronounced labor the shortages. Labor subcontracting practices are used sometimes to increase production rates and meet project deadlines. This paper explains and analyses labor subcontracting practices currently being used in many places around the world (and especially in the Gulf Countries) and in particular defines a maximum overtime rate for laborers in the laborer-subcontracting method ensuring that the contractor gains both the time saved during overtime and also reduces the cost per unit produced. The mathematical model used formalizes a closed-form equation for overtime pay in similar situations and as such can be applicable worldwide. Data was collected from representative projects that employed such practices from various trades. Validation of the model and formula has been tested successfully by analyzing historic data. The results prove that contractors often do not reach the optimum use of their practices resulting in a higher cost per unit. The presented model and the analysis should be of interest to many contractors currently involved in the practice or considering its use and to those who wish to find new methods that would help in eliminating as much wastes as possible by allocating their resources in the most efficient way.

• Smart Structures and Systems
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• v.12 no.3_4
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• pp.415-426
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• 2013

Condition assessment and monitoring of bridges is critical for safe passenger travel, public transportation, and efficient freight. In monitoring, displacement measurement capability is important to keep track of performance of bridge, in part or as whole. One of the most important parts of a bridge is the expansion joint, which accommodates continuous cyclic thermal expansion of the whole bridge. Though expansion joint is critical for bridge performance, its inspection and monitoring has not been considered significantly because the monitoring requires long-term data using cost intensive equipment. Recently, a wireless smart sensor network (WSSN) has drawn significant attention for transportation infrastructure monitoring because of its merits in low cost, easy installation, and versatile on-board computation capability. In this paper, a rapid wireless displacement monitoring system, wireless hybrid sensor (WHS), has been developed to monitor displacement of expansion joints of bridges. The WHS has been calibrated for both static and dynamic displacement measurement in laboratory environment, and deployed on an in-service highway bridge to demonstrate rapid expansion joint monitoring. The test-bed is a continuous steel girder bridge, the Founders Bridge, in East Hartford, Connecticut. Using the WHS system, the static and dynamic displacement of the expansion joint has been measured. The short-term displacement trend in terms of temperature is calculated. With the WHS system, approximately 6% of the time has been spent for installation, and 94% of time for the measurement showing strong potential of the developed system for rapid displacement monitoring.

• Journal of Digital Convergence
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• v.17 no.7
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• pp.157-165
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• 2019

Geron-technology contributing to successful "Aging in place" increases the quality of life for the elderly and decreases the social caring cost. This study aims to identify influencing factors on pre-implementation acceptance of geron-technology for the elderly residing in a community. Data for 129 participants were analyzed. Results indicated that location, physical function, lack of technical support by family members, and the high financial cost as a 28% power were identified as the influencing factors on pre-implementation acceptance of geron-technology. Therefore, in the development of health and welfare strategy, these influencing factors should be considered in order to archive 'aging in place' for the elderly.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.2
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• pp.173-184
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• 2021

In this study, internationally widely utilized bioeconomic models were used to make a comparison and analyze the effectiveness of red snow crab fisheries management measures. As a specific effect analysis, biological and economic effects of both total allowable catch (TAC) and effort reduction management measures were analyzed simultaneously. Model results showed that the red snow crab biomass would be decreased from 106,000 tons to 73,076 tons after ten years when the TAC is set to and maintained at the current level of 26,000 tons. The amount of biomass would be increased to 125,316 tons when the level of TAC is set to 22,000 tons. In cases of reduced fishing efforts, a 30% decrease from the current level would result in greater biomass and NPV would be also estimated at the highest level. In addition, a sensitivity analysis by market price was conducted to analyze the minimum TAC level of the red snow crab offshore pot fishery. Results showed that the minimum TAC level would be 8,210 tons when the market price increased by 30% and it would be also 15,247 tons when the market price decreased by 30%. Furthermore, results of the sensitivity analysis by fishing cost showed that the minimum TAC level was analyzed to be 13,857 tons when the fishing cost increased by 30% from the current level.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.91-97
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• 2021

The United States is responding to evolving cyberattacks through the Commercial Solutions for Classified Program (CSfC). Authorized safety evaluation and certification are being carried out so that US government agencies can quickly introduce civilian commercial security products into the national pavilion. Commercial security products registered in the CSfC process can be used by defense agencies through a rapid approval process. Defense agencies approve commercial security products without duplicate evaluation. Approved security products can reduce the time, cost, and cost of the approval process required to implement the defense information system. In this study, security control for 4 types of network security architecture MSC (Multi-Site Connectivity), MA (Mobile Access), Campus WLAN, and DAR (Data at Rest) proposed by the US National Security Agency (NSA) for introduction to national defense A detailed analysis was performed on the items.

• International journal of advanced smart convergence
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• v.4 no.1
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• pp.11-17
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• 2015

Fouling in heat exchanger becomes a major problem of dairy industry and it increases the production cost. These are lost productivity, additional energy, additional equipment, chemical, manpower, and environmental impact. Fouling also introduces the risk of food safety due to the improper heating temperature which allow the survival of pathogenic bacteria in milk, introducing biofilm formation of pathogenic bacteria in equipments and spreading the pathogenic bacteria to milk. The aim of this study is to determine the fouling rate during pasteurization process in heat exchanger of pasteurized milk produced by Village Cooperative Society (KUD) "X" in Malang, East Java Indonesia by using empirical modeling. The fouling rate is found as $0.3945^{\circ}C/h$ with the heating process time ranged from 0 to 2 hours and temperature difference (hot water inlet temperature and milk outlet temperature) ranged from 0.654 to $1.636^{\circ}C$. The fouling rate depends on type and characteristics of heat exchangers, time and temperature of process, milk type, age of milk, seasonal variations, the presence of microorganism and more. This results will be used to plan Cleaning In Place (CIP) and to design the control system of pasteurization process in order to maintain the milk outlet temperature as standard of pasteurization.

• Journal of Environmental Impact Assessment
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• v.15 no.5
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• pp.289-297
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• 2006

The study investigates the problems of silt protector used for mitigation measure of suspended sediments (SS) during coastal construction and provides their improvements based on the field investigation and analysis of the environmental impact assessment reports for the coastal development projects of Korea. The field investigation along west, east and south coasts of Korea reveals a variety of problems in the installation and management of silt protector solely used for the SS mitigation in Korea. Major problems include installation itself, low cost and quality of silt protector, and maintenance. These problems superimpose the effectiveness of silt protector in mitigating coastal environment impact. The present study provides the specific guideline on the project type needed for the installation of silt protector, installation standard and planning, maintenance and management. The study also suggests new mitigation options such as environmental window to limit the construction period and environmental dredger to compensate for the deficits of silt protector.

• Proceedings of the Korean Society of Crop Science Conference
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• 2001.09a
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• pp.72-90
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• 2001

Environment agriculture carried out from 1999 in Daeho reclaimed saline area, located in central east cost of Choongnam Korea, resulted in dramatic reduction of amount of nitrogen fertilizer and application times and amount of pesticides. The ecological status of Daeho reclaimed saline area was considered to still very sound from the results of ecological survey on flora and fauna. However, it was desirable to adapt precision agriculture for production of high eating quality of rice and preservation of Daeho ecosystem. Especially, precise application of nitrogen and phosphorus fertilizer was recommendable for prevention of water pollution in environment rice cultivation by duck or mud snail or crab. The bioefficacy of Scirpus maritimus and Echinochloa crus-galli in paddy field of environment rice cultivation by duck or mud snail or crab in Daeho reclaimed saline area was revealed very low. Therefor, it was concluded that the pre-measures of reduction of natural weed population were necessary for successful environment agriculture. The most desirable and ideal environmentally sound agriculture in Daeho reclaimed saline area was performance of crop rotation, introduction of legume crops and green manure crops, and also, simultaneous management of crop production and animal husbandry for smooth flow of energy cycle within the closed Daeho ecosystem.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1314-1321
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• 2010

The west express way which links south west area of the central city of Seoul has been notorious for extremely heavy traffics since its first opening in 1991(i.e. the average vehicle speed is less than 25km/h, a daily traffic is 112,000 and among them, more than 94% of the vehicles are the light vehicles). The city government recently initiated a new BTO(Build-Transfer-Operate) project as an alternative in releasing heavy traffic and a high construction cost. The proposed underground express road is the first double-level tunnel (i.e. a total length of road is 10,91km and the tunnel is 9.308km long) ever built in South Korea, while such tunnel system is not new worldwide as such A86 East tunnel in France, SMART tunnel in Malaysia, and Fuxing tunnel in China. This paper discusses major design issues regarding the internal structures such as deck slab, and secondary liner.