• Journal of Korea Water Resources Association
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• v.44 no.1
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• pp.23-30
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• 2011

Any significant inflow of fresh water due to flood or snow melting can rapidly reduce salinity at the bay. In such a case, the habitat environment in the sea near river mouth can be partly destroyed. Therefore, research to understand the salinity distribution quantitatively at the bay for the utilization of natural environment and for the inhabitant conservation must be very important. In this study, the investigation on the relationship between satellite image and turbidity is carried out first, and then the salinity distribution at the bay using the relationship between turbidity and salinity is derived. The main results are as follows. First the reappearance ability of RGB bands respectively of the satellite image is investigated, and then it was confirmed that the combination of band2 and band3 expressed best the movement characteristics of turbid water at the bay is chopped up into 4 small areas. Second the turbidity of river mouth is estimated using the travel time from the upward monitoring station to the river mouth. Finally the satellite image is converted into the salinity distribution by the correlation of salinity and turbidity. It is confirmed that the salinity distributions obtained from above three investigation methods are quite reasonable and clear.

• Journal of the Korean Institute of Navigation
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• v.13 no.3
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• pp.37-44
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• 1989

Recently recognize the labor productivity of port physical distribution system in the port and shipping areas, Much Efforts for evaluating this productivity has been made continuously. BUt still there is little study, so far, on a systematic research for the management of port labor gangs, and even those were mainly depended on a rule of thumb. Especially the object of this study is to introduce the method of optimal allocation and assignment for the labor gangs per pier unit in the multiple ships berthed at an arbitary pier or port. In case the multiple ships have a homogeneous cargoes or do not have sufficient labor gangs to be assigned. The problem of optimal allocation and assignment of the labor gangs to be i) formalized with multi-state decision process in form of difference equation as the pattern which converted the independent multiple ships into a single ship with the intra-multiple ships, and ii) the optimal size of labor gangs could be obtained through the simple mathematical method instead of complicated dynamic programming, and iii) In case of shortage of labor gangs available the evaluation function considering the labor gangs available and total shift times was introduced, and iv) the optimal allocation and assignment of labor gangs was dealt at the point of minimizing the summation of the total shift times and at the point of minimizing the total cost charged for the extra waiting time except PHI time during port times for the multiple ships combinations.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.9
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• pp.172-181
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• 1999

The brakes employed on commercial vehicles must be able to withstand three types of demanding services which are use-emergency stops from high speed, many repeated stops as in a delivery or bus route, and speed control in mountain descents. Two type of friction brakes are in use ; drum breaks and disc brakes. Drum brakes are of the internally expanding type in which two shoes fitted externally with friction material are forced outward against the inside of a rotating drum on the wheel unit. In this case, the Braking power is produced by the friction force between a drum and a lining, and is converted into heat. In this research an unsteady state heat transfer analysis for drum brake system of heavy truck has been performed by ABAQUS/standard code in the case of single-braking and the repeated braking condition. The temperature histories obtained by the finite Element analysis have been compared with the result calculated by the simplified formulation and the result obtained by the experiment of real vehicle conditions.

• The Journal of Asian Finance, Economics and Business
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• v.4 no.2
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• pp.55-68
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• 2017

This research is carried out to investigate the relationship between sustainability practices and performance in a financial sense for Malaysian Oil and Gas sector. Objectives include to study the state of sustainability disclosure among Malaysian oil and gas companies, to understand if companies that practiced sustainability had better performances to their financial bottom-line and to conduct a data analysis to understand the relationship between Environmental, social and governance performance [represented by the acronym ACSI] and financial performance. Sustainability performance is measured using ACSI checklist, which is an adaptation of the GRI 3.0 by Global reporting initiative while financial performance was measured on financial and profitability parameters namely EBITDA, EPS and PE ratio. Secondary data sources are used which were then converted into a rating scale to develop quantitative data. SPSS 21 is used for the analysis. The result shows that the majority of oil and gas companies in Malaysia had poor performance in terms of sustainability disclosure. On all three chosen profitability parameters, the companies that practiced sustainability were found to perform better than their counterparts that did not. Strong and significant relationship exists between sustainability practices and better financial performance.

• The Journal of Korean Obstetrics and Gynecology
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• v.19 no.3
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• pp.247-256
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• 2006

Purpose : To research the Skin Resistance Variability(SRV) of premature ovarian failure(POF) patients by Autonomic Bioelectric Response Recorder(ABR-2000 system, Meridian, Korea) and report the specific results in SRV of POF patients. Methods : We measured SRV of 17 POF Patients who came to Conmaul Oriental Medical Hospital during August 2005 ${\sim}$ July 2006 by ABR-2000 system. We analyzed the results which height of graph Part was converted into 0${\sim}$10, and the readings of Low/Normal/High. Results : The mean value of graph height on each(1, 2, 3) part is lower than normal range(4-6) in POF patients. The distribution ratio of Low/Normal/High on each(1, 2, 3) part shows that there are much more Low proportion in POF patients. Conclusion : The low graph height of POF patients on 1, 2, 3 part means that conductivity & capacitance of POF patients is low, especially on head.

• Korean Journal of Veterinary Research
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• v.26 no.1
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• pp.61-68
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• 1986

This paper described the distribution and transmissibility of BLV(bovine leukemia virus), the relationship between antibodies against BLV and lymphocyte count in 313 dairy cattle from 36 herds, the clinical signs and hematological findings of 2 lymphosarcomatous cattle in the northern area of Kyungpook. Eighty three (26.5%) of 313 cattle from 36 herds were positive for BLV antibodies and 19 (52.8%) of 36 herds were infected with BLV by the immunodiffusion test with BLV-gp antigen. The rate of BLV infection in cattle varied from 9.5 to 87.5% in 19 positive herds, it was higher in herds pastured during summer and included lymphosarcomatous onset than the other and also higher with the age. Eight (88.9%) out of 9 cattle which showed persistent lymphocytosis by the hematological test were positive for BLV antibodies. After 5 to 14 months, 13 (31.0%) of 42 cattle being negative for BLV antibodies in the positive herds converted into positive. Two lymphosarcomatous cattle were identified to be EBL (enzootic bovine leukemia) by the clinical sign, hematological examination and serological test.

• Water Engineering Research
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• v.6 no.1
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• pp.31-38
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• 2005

Groundwater recharge is defined in an addition of water to groundwater reservoir. Recently, many people have been moving to the Edwards aquifer and urban and agricultural industry have been expending. Hydrologists and water planning managers concern about insufficient groundwater amounts and irrigation water price variability. In this paper, I focus on estimates of local recharge volumes and quantify preferential flow through GIS technique. Chloride Mass Balance (CMB) and hydrochemical components have been widely applied to recharge rate and evaluate flow paths. The CMB method is based on relationship between wet-dry chloride deposition data and Rainfall data. These data are manipulated using ArcGIS. Especially, hydrochemical concentration distribution is good index for groundwater residence times or flow paths such as $[Mg^{2+}]/[Ca^{2+}],[Cl]$ and log$([Ca^{2+}]+[Mg^{2+}])/[Na^+]$. Well information such as hydrological-hydrochemical data are imported into ArcGIS and manipulated by interpolation techniques. For each potentiometric surface and water quality, point data are converted to spatial data through each Kriging and Inverse Distance Weighted (IDW) techniques.

• Korean Journal of Optics and Photonics
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• v.14 no.1
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• pp.44-50
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• 2003

This paper describes the thermal effect at Nd:YAG using a laser-diode side-pumping. To detect the depolarization loss and the retardation caused by the thermal effect, a λ/4 plate is inserted between the polarizer and the Nd:YAG laser material. Using a CCD has allowed detection of the variation of the beam pattern that could analyze the change of the refractive index of the Nd:YAG laser material by the thermal effect. Through the change of the probe beam power, we know that 21% of the pumping power was converted into heat in the material. The depolarization loss was 24.7% under a temperature of $25^{\circ}C$ of the laser material and a pumping power of 15 W. The inhomogeneous distribution showed that the retardation angle was 7$^{\circ}$ in the center of the material and 19$^{\circ}$ on the edge of it. It is confirmed that the thermal effect is analyzed at the each point of the laser material and it suggests an effective method to reduce the thermal effect on the LD side-pumped laser material.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.4
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• pp.555-563
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• 2012

Due to the importance of energy-saving and CO2 reduction is being emphasized in the world, efforts to find a solution for the problems is increasing rapidly. In particular, the renewable energy is on understanding as a breakthrough for the protection of the environment and the economic development, so it is intensively fostered as future industries. Developed countries are already pursuing policy and technology development related with renewable energy. In this paper, we will develop MHD(Magneto Hydro Dynamics) technology to supply the commercial power that can is targeted at water pipe related with hydro power among renewable energy technologies. Kinetic energy of fluid flowing in the water pipe is converted into electric power. It allows stable power supply to the various sensors and devices on water pipe. We have performed several experiments to verify the application possibility of the developed technologies and present the result and a method of performance improvement of the technologies.

• Particle and aerosol research
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• v.8 no.1
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• pp.29-35
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• 2012

The Faraday cup electrode of different size has been developed and evaluated to investigate the diffusion effect of particles by Brownian motion in a particle beam mass spectrometer(PBMS). Particles which focused and accelerated by aerodynamic lens are charged to saturation in an electron beam, and then deflected electrostatically into a Faraday cup detector for measurement of the particle current. The concentration of particles is converted from currents detected by Faraday cup. Measurements of particle current as a function of deflection voltage are combined with measured relationships between particle velocity and diameter, charge and diameter, and mass and diameter, to determine the particle size distribution. The particle currents were measured using 5, 10, 20, 40 mm sized Faraday cup that can be move to one direction by motion shaft. The current difference for each sizes as a function of position was compared to figure out diffusion effect during transport. Polystyrene latex(PSL) 100, 200 nm sized standard particles were used for evaluation. The measurement using 5 mm sized Faraday cup has the highest resolution in a diffusion distance and the smaller particles had widely diffused.