• Journal of Ocean Engineering and Technology
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• v.20 no.1 s.68
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• pp.1-6
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• 2006

The effects of microstructure on the damping capacity and tensile properties of 316L stainless steel were investigated. Increasing the degree of cold working, the volume fraction of $\varepsilon-martensite$ decreased after rising to maximum value at specific level of cold working, the volume fraction of d-martensite slowly increased and then dramatically increased from the point of decreasing $\varepsilon-martensite$ volume fraction. Increasing the degree of cold working, the behnvior of damping capacity is similar to that of the $\varepsilon-martensite$. After the damping capacity showing the maximum value at about $20\%$ of cold rolling, damping capacity was decreased with the volume fraction of $\varepsilon-martensite$. Tensile strength was proportional to the volume fraction of d-martensite, and elongation steeply decreased in the range low volume fraction of a'-martensite, then slowly decreased in range the above $10\%$ volume fraction of d-martensite. The damping capacity and elongation is strongly controlled by the volume fraction of $\varepsilon$ martensite with liner relationship. However, the effect of the volume fraction of d-martensite and austenite phase on the damping capacity was not observed. Tensile strength was governed by the volume fraction of d-martensite.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.5
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• pp.857-862
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• 2008

This paper evaluate the performance using a simulated 490KHz narrow band filter based on characteristic parameters appropriately extracted from 490KHz band-pass filter after considering each characteristic, which is modeled on equivalent circuit and applied to NAVTEX receiver using crystal oscillator. The evaluation results show that the value of a series capacitor of crystal oscillator has only little capacity by Cs=21.094fF and the bandwidth characteristics of filter go worse as the capacity value of crystal oscillator grow increase. Moreover, the series inductance value of crystal oscillator has a relatively big value by L=5H, therefore the bandwidth characteristic according as inductance's capacity shows more little effect than the capacity.

• Journal of Korean Society of Water and Wastewater
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• v.36 no.4
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• pp.229-237
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• 2022

The sewer capacity design have been based on the Huff model or the rational equation in South Korea and often failed to determine optimal capacity, resulting in frequent urban flooding or over-sizing. A time distribution of rainfall (i.e., Huff or ABM method) could be used instead of a rainfall hyetograph obtained from statistical analysis of previous rainfalls. In this study, the Huff method and the ABM method, which predict the time distribution of rain intensity, which are widely used to calculate sewage pipe drainage capacity using the SWMM, were compared with the standard rainfall intensity hyetograph of Seoul. If the rainfall duration was 30 minutes to 180 minutes, the rainfall intensity value calculated by the Huff model tended to be less than the rainfall intensity value of the standard rainfall intensity in the initial 5-10 minutes. As a result, more than 10% to 30% of under-design would be made. In addition, the rainfall intensity value calculated by the Huff model from the section excluding the initial 5-10 minutes of rainfall to the rainfall duration was calculated larger than the value using the standard rainfall intensity equation, which would result in an over-design of 10% to 30%. In the case of a relatively long rainfall duration of 360 minutes (6 hours) to 1,440 minutes (24 hours), it showed an lower rainfall intensity of 60 to 90% in the early stages of rainfall, but the problem of under-design had been solved as the rainfall duration time had elapsed. On the other hand, in the alternating block method (ABM) method, it was found that the rainfall intensity at the entire period at each assumed rainfall duration accurately matched the standard rainfall intensity hyetograph of Seoul.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.5
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• pp.1-13
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• 2017

Recently, due to worldwide industralization and urbanization, natural environment has been severly damaged and global warning is worsening. Heat wave, torrential rainfall, typhoon and other natural disasters continuously occur due to global warming. Policies such as carbon emission regulation are taken into effect to solve such problems. Such global trend has affected interest to natural ecosystem and developed as a concept of ecosystem-services. This study particularly focused on ground water storage capacity among various ecosystem-services such as climate control and soil formation. It is because Korea suffers from drought and flood every year. Therefore, this study aims to understand objective numerical value of ecosystem-services value regarding ground water storage capacity of biotop classes based on relationship among precipitation, amount of evapotranspiration, and runoff of 7 regions of Chilgok-gun, Gyeongsangbuk-do and to convert the value into economic value. The study calculated ground water storage capacity based on relationship among precipitation, amount of evapotranspiration, and run off. Calculated amount of each capacity was 29.26 million ton($30.2mm/m^2$), 430.46 million ton($140.4mm/m^2$), 11.30 million ton($150.1.0mm/m^2$), 33 milion ton($3.0mm/m^2$). Economical value of ecosystem-service by each biotop classes appeared 4,128,800 thousand KRW ($21.32KRW/m^2$) for agricultural biotop, and 60,403,600 thousand KRW ($98.52KRW/m^2$) for forest biotop, 1,572,800 thousand KRW ($104.4KRW/m^2$) for grassland biotop, and 47,600 thousand KRW ($2.18KRW/m^2$) for bare ground biotop. The result of this study like above, it will be used as important evidentiary material to preserve natural resource effectively from various development business and policies that damages natural eco-system. Also, it is judged that ecosystem-service value by each land coverage will be used as important material for preparing legalistic institution such as establishing natural environment preservation plan, budget for alternative forest resource creation cost.

• Journal of the Korean Geotechnical Society
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• v.35 no.6
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• pp.27-38
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• 2019

Bearing capacity of a pile in homogeneous soil is the sum of end bearing and skin resistance, and the skin resistance is more prominent in sandy soil. Bearing capacity of a pile in pile groups especially in sandy ground should be designed under the consideration of the influence by the adjacent piles. In this study, the end bearing capacity of a pile in pile groups was experimentally investigated. For this purpose, piles were installed in sandy ground in a circular test box, and end bearing - settlement behavior of the pile was measured while the pile was loaded. As the results, end bearing - settlement relation curves of the piles showed a distinct limit value. Limit value of the end bearing was little affected by skin friction and pile diameter, and it became a constant value as pile penetrates deeper. End bearing was not affected by the adjacent piles in a group of piles, when their clearance was larger than the pile diameter.

• Journal of Korea Entertainment Industry Association
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• v.15 no.5
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• pp.33-43
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• 2021

Kakao M and Kakao page have been merged to form contents corporation, Kakao entertainment. Kakao M has 15 contents management agencies and 4 music labels, in addition to movie and drama productions. Kakao Page currently holds IP rights for about 8,500 content stories. This study explores the relationship between M&A for absorptive capacity and content value chain by considering the factors that determine boundary spanning behaviors. Using the Kakao entertainment in-depth case study as the practical lens, research results of this study are suggested. Kakao's effective M&A activities are critical key factor for absorptive capacity in the entertainment industry and has a strong network with advantage assets. Also, as the contents business becomes even more competitive, Kakao need to venture beyond entertainment boundaries to seize creative opportunities. Kakao entertainment with absorptive capacity and boundary spanning behaviors through M&A and contents value chain best qualified for entertainment dominant strategy.

• International Journal of Highway Engineering
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• v.17 no.4
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• pp.107-115
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• 2015

PURPOSES: This study analyzes the characteristics of traffic flow on freeway sections under daytime and nighttime conditions to improve traffic safety, and suggests a method to estimate an accurate freeway capacity value that reflects these characteristics. METHODS : The trends and differences in capacity were investigated using comprehensive field data collected under both daytime and nighttime conditions on freeway sections with designated speeds of 80, 100, and 120 kph. RESULTS : The capacity values under nighttime driving conditions were reduced by 3.3%, 6.9%, and 8.8% at 80, 100, and 120 kph, respectively. Several nighttime adjustment factors were deduced for each designated speed category from the analysis results. CONCLUSIONS : It is expected that more accurate capacity values can be estimated for freeway sections under nighttime conditions by applying the resulting adjustment factors. In addition, traffic safety will be improved through the increased efficiency of traffic management on these freeway sections.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.12
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• pp.1043-1048
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• 2003

An experimental investigation was executed to determine the capacity degradation due to non-uniform refrigerant distribution in a multi-path evaporator. In addition, the possibility of recovering the capacity reduction by controlling the refrigerant distribution among refrigerant paths was assessed. The finned-tube evaporator, which had a three-path and three-depth-row, was tested by controlling inlet quality, exit pressure, and exit superheat for each refrigerant path. The capacity reduction due to superheat unbalance between each path was as much as 30%, even when the overall evaporator superheat was kept at a target value of 5.6$^{\circ}C$. It may indicate that the internal heat transfer within the evaporator assembly caused the partial capacity drop. For the evaporator having air mal-distributions, the maximum capacity reduction was found to be 8.7%. A 4.5% capacity recovery was obtained by controlling refrigerant distribution to obtain the target superheat at the outlet of each path.

• Environmental Engineering Research
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• v.17 no.2
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• pp.117-122
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• 2012

A central composite design and response surface methodology were applied to investigate the optimum conditions for maximum adsorption capacity in activated alumina as an adsorbent. The optimized conditions were determined for adsorption capacity using variables of flow rate and temperature. It was found that flow rate and temperature greatly influenced the adsorption capacity, as determined by analysis of variance analysis of these variables. Statistical checks indicated that second order polynomial equations were adequate for representing the experimental values. The optimum conditions for adsorption capacity were $0^{\circ}C$ and 2,718 mL/min, with the estimated maximum adsorption capacity of 17.82%. The experimental adsorption capacity was 17.75% under these optimum conditions, which was in agreement with the predicted value of 17.82%.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.111-112
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• 2007

This paper presents the capacity payment in electricity power markets. The capacity payment (CP) needs to recover fixed costs. But most CP is allocated by energy policy. So, this paper analysis CP using capacity proportion and Reliability Pricing Model (RPM). The capacity proportion method uses base capacity price and supply available capacity. The RPM method uses value of each region and operation attribute of each generator.