• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.1
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• pp.161-167
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• 2001

The purpose of this study is to find out the difference of Zoysia matrella's evaporation in between 100 percent soil and mixed soil with 50 percent of perlite to create green spaces on the artificial ground. It is believed that the weight against the artificial ground will be reduced, provided the vegetation is possible in the circumstance of the mixed sol with 50 percent of perlite. The study employed a modified Makkink's model by Iwasa who had developed the model for estimating Zoysia matrella's evaporation in the natural ground using the Makkink's formula in 1997 at Chiba University, Japan. The parameter of Makkink's formula is the solar radiation. For that reason, the Makkink's formula is simple and easy to measure the parameter and has a high utility. If the outcomes from mixed soil are close to modified Makkinks formula, the modified Makkink's formula will be applied to estimate in the artificial ground with mixed soil with 50 percent of perlite. Weather observation and actual amount of evaporation of Zoysia matrella have been measured, and the relation between weather condition and actual amount of evaporation had been also investigated. In line with this, we found out that there is a relevant relationship between daily average temperature, the modified Makkink's model by Iwasa, and the actual amount of evaporation. As the results of the experiment, the outcomes from mixed soil with 50 percent of perlite have very high relation to 100 percent soil. In addition, mixed soil has more adhesion with water than natural soil. However, it needs to be adequately maintained in terms of fertilization and damage from disease and harmful insects until the gras fastens its roots into the soil. By using mixed soil with 50 percent of perlite, the load from soil on the artificial ground can be reduced. The study on the growth of the grass throughout the plant vegetation and the actual amount of evaporation in the mixed soil with 50 percent of perlite should be performed in the future.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.3
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• pp.167-176
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• 1995

The purpose of this study is to suggest objective basic data for park management proposal through the quantitative analysis of users' behaviors and satisfaction for the actual conditions of management in Moaksan provincial park. For this, users' behaviors and socio-ecnomic characteristics have been analyzed. Specifically, it attempts to investigate users' anticipation and degree of satisfaction applied Expectancy Theory by Likert scale. And users' satisfaction for the actual conditions of management had been analyzed by using the multiple regression. Results of this study can be summarized as follows ; From the aspect of utilization reality, the male usage was silighty higher than female usage, and the usage rate reality, the male usage was slighty higher than female usage, and the usage rate among the young and students such as university students also appeared slightly higher than the norm. Due to the fact, subject park had been provincial park, bus usage was predominant, and users' visit park 1 or 2 times a year. Generally, the value of users' post occupancy evaluation were higher than those of anticipated, and Use in night and facilities were lower. A sense of the season, dense of forest, beauty of skyline and a perspective view appeared as main explicatory variables having positive effects on the satisfaction level for the landscape. Amount of plant and shade were positive variables on the satisfaction and users' had dissatisfaction with trial damage. According to the multiple regression analysis, the major variables to the satisfaction for the actual condition of vegetation management were diversity, recovery of artificial injury.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.12
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• pp.545-552
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• 2003

When a Si PIN diode is exposed to fast neutrons, it results in displacement damage to the Si lattice structure of the diode. Defects induced from structural dislocation become effective recombination centers for carriers which pass through the base of a PIN diode. Hence, increasing the resistivity of the diode decreases the current for the applied forward voltage. This paper involves the development of a neutron sensor based on the phenomena of the displacement effect damaged by neutron exposure. The neutron effect on the semiconductor was analyzed. Several PIN diode arrays with various thickness and cross-section area of the intrinsic layer(I layer) were fabricated. Under irradiation tests with a neutron beam, the manufactured diodes have a good linearity to neutron dose and show that the increase of thickness of I layer and the decrease of cross-section of PIN diodes improve the sensitivity. Newly developed PIN diodes with thicker I layer and various cross section, were retested and then showed the best neutron sensitivity at the condition that the I layer thickness was similar to a side length. On the basis of two test results, final discrete PIN diodes with a rectangular shape were manufactured and the characteristics as neutron detectors were analyzed through the neutron beam test using on-line electronic dosimetry system. Developed PIN diode shows a good linearity as dosimetry in the range of 0 to 1,000cGy(Tissue) and its neutron sensitivity is 13mV/cGy at constant current of 5mA, that is three times higher than that of commercially available neutron detectors. And the device shows little dependency on the orientation of the neutron beam and a considerable stability in annealing test for a long period.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2000.11a
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• pp.1-2
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• 2000

In chip plating, several parameters must be taken into consideration. Current density, solution concentration, pH, solution temperature, components volume, chip and media ratio, barrel geometrical shape were most likely found to have an effect to the process yields. The 3 types of barrels utilized in chip plating industry are the onventional rotating barrel, vibrational barrel(vibarrel), and the centrifugal type. Conventional rotating barrel is a close type and is commonly used. The components inside the barrel are circulated by the barrel's rotation at a horizontal axis. Process yield has known to have higher thickness deviation. The vibrational barrel is an open type which offers a wide exposure to electrolyte resulting to a stable thickness deviation. It rotates in a vertical axis coupled with multi-vibration action to facilitate mixed up and easy transportation of components. The centrifugal barrel has its plated work centrifugally compacted against the cathode ring for superior electrical contact with simultaneous rotary motion. This experiment has determined the effect of barrel vibration intensity to the plating thickness distribution. The procedures carried out in the experiment involved the overall plating process., cleaning, rinse, Nickel plating, Tin-Lead plating. Plating time was adjusted to meet the required specification. All other parameters were maintained constant. Two trials were performed to confirm the consistency of the result. The thickness data of the experiment conducted showed thatbthe average mean value obtained from higher vibrational intensity is nearer to the standard mean. The distribution curve shown has a narrower specification limits and it has a reduced variation around the target value. Generally, intensity control in vi-barrel facilitates mixed up and easy transportation of components. However, it is desirable to maintain an optimum vibration intensity to prevent solution intrusion into the chips' internal electrode. A cathodic reaction can occur in the interface of the external and internal electrode. 2H20 + e $\rightarrow$M/TEX> 20H + H2.. Hydrogen can penetrate into the body and create pressure which can cause cracks. At high intensity, the chip's motion becomes stronger, its contact between each other is delayed and so plating action is being controlled. However, the strong impact created by its collision can damage the external electrode's structure there by resulting to bad plating condition.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.138-147
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• 2018

With the recent series of damage caused by earthquakes in Korea, such as Gyeongju and Pohang, we know that Korea is no longer a safe zone for earthquakes and that we need to be prepared for them. In addition, bridges built prior to the introduction of seismic design concepts remain without adequate seismic reinforcement measures, and earthquake reinforcement should be performed efficiently considering economic and structural safety. Preliminary assessment of seismic performance of existing bridges is divided into four seismic groups, taking into account seismicity, vulnerability and Impact, considering the magnitude of the existing bridge's seismic, and prioritization for further evaluation of seismic performance. In this study, unlike the existing anti-seismic reinforcement priority method, scores are calculated based on the seismic design criteria applied to bridges, importance coefficient of the bridge including the zone coefficient and the Importance, vulnerability index of the bridge including the soil condition and the elapsed years, detail coefficient of the bridge including the superstructure form, the span length, the width, the height, the design load, and the daily traffic volume. The calculated score items will be weighted and grouped according to the results. Using this, a simpler and more efficient algorithm was proposed to determine the priority of seismic reinforcement on a bridge.

• Journal of Korean Institute of Fire Investigation
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• v.10 no.1
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• pp.47-57
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• 2007

If it were the occurrence of fire by electricity with the rapid growth of economy, it would be serious damage for nation that effect human life and properties. To prevent electrical fires, it was basic countermeasure that make detail statistics classified by the source, place etc. with examining correct cause of fire. In this paper, we analuzed the present condition of fire occurrence of the lastest ten years and classified fires by the source, place, month in 2006. In addition our corporation staff execute in-depth and professional research on the actual state of electrics fire by visiting fire stations fire of the whole country for 8,554 electric fires in 2005. I expect this thesis to be used for preventing electric fires and providing a stepping stone on correct production of fire statistics.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.3
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• pp.142-163
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• 2009

Taebaek city is located in the mountainous plateau area therefore the major industry was coal industry. According to dramatically declining of the major industry, Taebaek city is need to alternative industry which associated with considering the geographical characteristics of natural tourism resources for increasing the local economy. On the basis of these reasons, this study can be suggested ecological planning and mitigation of deterioration technique about the these study site. That is the reserved area for mountainous experience theme park. As the results of environmental ecology assessment are following as; The natural ecosystem areas, multi-layer structure forest such as forest of Pinus densiflora, forest of Quercus mongolica and deciduous forest have a high value of nature, diversity and potential. In addition, wild bird habitats were important area as a inhabitation, breeding, feeding and hiding. Therefore, on these areas should be preserved. Also, it needs to conserve on there such as more than three types of wild bird inhabitate areas, the fringe of high biological diversity, the wetland that have got good vegetation condition and the function of amphibia, reptiles crossing. In addition, inhabitation, the waterway of wetland form that have got wide waterside width needs to conserve. In conclusion, on the basis of analysis results such as conditions of plan, environment, ecological assessments, survey informations are able to suggest the connectivity of the axis of forest and management plan. Moreover, in the part of forest restoration plan, we suggest the plan of transplant for a compensation of damaged forest by land use.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.8 no.1
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• pp.81-86
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• 1996

Subsea pipelines have an important role in the overall tasks of offshore oil and gas production but arc exposed to various hazards with high potential risks of damage resulting in serious economic loss and impact on ocean environment. In this paper, the dynamic free span is analysed, which is one of main risk factors against the safety of subsea pipelines and the allowable length of dynamic free span which is important for the design of subsea pipelines is determined. The allowable free span length is examined by considering the relationship between vortex shedding frequency and natural frequency of pipeline free span, and the variation of the allowable length is analysed for different boundary conditions of pipe ends. The free span is regarded as a beam on elastic foundations and the boundary condition of the beam is generalized by modelling as restrained by linear and rotational spring at each end. A non-dimensionalized curve is obtained to facilitate the determination of exact allowable length of dynamic free span for subsea pipelines and is applied to the pipelines which is to be installed in the gas fields of the south of East Sea of Korea.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.4 s.19
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• pp.79-84
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• 2005

When polymeric materials are exposed to fire condition, a lot of heat and toxic gases evolved and cause damage to property and human being. Especially toxic gases are major hazard to life safety. This study FTIR(Fourier Transform Infrared) spectrometer analysis was performaed to etermine the gas analysis and the concentration of gases evolved from PVC, FRP, SMC and Ureathane foam using ASTM E 1678 fire model. And FED toxicity index calculated from FTIR data also presented. By the comparison of animal test adopted in KS F 2271 and FTIR gas analysis method, FTIR gas analysis method can replace current animal toxicity test and produce precise and quantitative combustion gas data.

• Journal of Korean Society of Disaster and Security
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• v.11 no.1
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• pp.1-5
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• 2018

Power plant is the important infrastructure to generate electricity. This plant in normally located next to river and seashore in order to take cooling water through intake. However, the plant is stopped when marine organism blocks the intake, and it caused damages by social and commercial. Therefore, air bubble barrier has been used to block marine organism in order to operate the plant properly. The aim of this study was to test the rates of cut off of floating substance by air bubble barrier to develop the facility for the plant. The test was conducted by current velocity, pressure of air, specific gravity of the substance and the layer of the barrier, and the result showed the blocking rates by the condition. It will be used as basic data to develop the air bubble barrier and to operate power plant properly from the marine organism.