• Korean Journal of Legislative Studies
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• v.27 no.2
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• pp.71-109
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• 2021

The purpose of this study is to find out what factors influence lawmakers' voting decisions in the plenary session. In particular, the study examines causes and characteristics of waffling and strategic waffling, which express opposition or abstention in a discharge petition or a vote at the plenary session despite participating in a bill sponsorship. The study on waffling is meaningful because it has not been covered in previous literatures. To this end, the Gadeokdo New Airport Special Act, which the National Assembly passed in February 2021, was set as an analysis target. The study examined the factors that affected legislators' voting decisions and participation in bill sponsorship and who were related with waffling. Statistical results showed that the age variable influenced the motion of the bill while seniority and party affiliation had an effect on the participation of the bill. Likewise, the study found that party affiliation and district had an influence on the approval of the bill. In addition, the analysis of waffling showed that lawmakers with higher seniority tended not to participate in the vote. It could be interpreted that lawmakers with more legislative experience judged that they would benefit from strategic waffling. There is a limit to understanding lawmakers' decision-making and waffling through a limited analysis of the Gadeokdo New Airport bill. However, given that lawmakers tend to choose avoidance strategies in ambiguous situations, and given the high intelligence of lawmakers who know better than anyone about the future impact of a new bill, the decision-making shown by lawmakers in each stage of the situation is a prudent judgment gained from their experience. It indicates that it is necessary to research the legislative activities of lawmakers in various ways.

• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.597-603
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• 2017

High-dose $^{131}I$ therapy has been generally carried out to remove remaining thyroid tissue or to cure metastasize lesion of patients who received full thyroidectomy due to differentiated thyroid cancers. In case high-dose $^{131}I$ therapy is carried out for a patient, the patient should be hospitalized being isolated for a certain period in order to restrict the amount of exposure to radiation of people at large from the patient within the limit of a level of radiation. Effective half-life is an important value to calculate how family members are exposed to radiation from a patient or to decide the period of isolation of the patient from the family members. Therefore, in this study we calculated the effective decay constant, effective half-life and period of isolation of high-dose $^{131}I$ therapy patient using NM670 SPECT/CT. As a result of carrying out this study, the effective half-life of high-dose $^{131}I$ therapy patients was derived and the time to reach the discharge level of 1.2 GBq was confirmed. When they were compared with each other in each of curative doses, the effective half-life did not have significant difference, but the time when the level of radiation remaining in the interior of the body to reach the criteria of isolation and discharge showed significant difference and it could be confirmed that the higher the curative dose the longer the period of isolation becomes. When the effective half-lives in each type of preparation were compared with each other, they did not show significant difference. However, When the times to reach the level of radiation that is the criteria of isolation and discharge in each type of preparations, they showed significant difference. The cause of the shortening of the isolation period for rhTSH patients group is decided to be low curative dose. Accordingly, if the current national health insurance (the insurance is applied to using of rhTSH in 3.7 GBq or lower) is maintained, while discerning them in each of types of preparation, we would be able to discharge patients at the time earlier than the current period of isolation (2 nights and 3 days).

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.1
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• pp.48-55
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• 2014

These Xenon flashlamp power supply for Ultra Violet has converter with high voltage conversion ratio. General model is composed of transformer with high voltage conversion ratio and voltage doubler rectifier circuit. Purpose of power supply leads dielectric breakdown of Xenon flashlamp and passes current rapidly. When passing current, it has to limit current to avoid over-heat, damage of electrode and acceleration of gas oxidation which are cause of performance degradation of lamps. Generally, inductors and resistors, which are called as "Ballast," are used to limit currents. Generally, Transformer has high turn ratio to make high voltages. But we can get high voltages using the transformer with low turn ratio which is driven with self resonance. Also, an advantage of self resonance is to make a circuit simply through impedance of transformer in resonance frequency which filters output voltage. As using an unique impedance of transformer, the circuit does not need other impedance elements like the ballast. So the power supply assures high efficiency of the arc discharge.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.3
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• pp.99-111
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• 2017

The purpose of this study is to provide a design and operation technical guideline for meeting the appropriate design criteria to bio-gasification facilities treating organic wastes. Based on the results obtained during the field surveys, the overall design and operation guidelines for bio-gasification facilities, monitoring items, cycle and commissioning period were presented. According to the flow of anaerobic digestion process, Various design factors for bio-gasification facilities were proposed in this study. When designing the initial anaerobic digestion capacity, 10 ~ 30% of the treatment capacity was applied considering the discharge characteristics by the incoming organic wastes. At the import storage hopper process, limit concentration of transporting organic wastes was limited to TS 10 % or less, and limit concentration of inhibiting factor was suggested in operation of anaerobic digester. In addition, organic loading rate (OLR) was shown as $1.5{\sim}4.0kgVS_{in}/(m^3{\cdot}day)$ for the combined bio-gasification facilities of animal manure and food wastes. Desulfurization and dehumidification methods of biogas from anaerobic digestor and proper periods of liquifization tank were suggested in design guideline. It is recommended that the operating parameters of the biogasification facilities to be maintained at pH (acid fermentation tank 4.5~6.5, methane fermentation tank 6.0~8.0), temperature variation range within $2^{\circ}C$, management of volatile fatty acid and ammonia concentration less than 3,000 mg/L, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.672-680
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• 2018

The opening angle of the duct cap assembly during the operation of a refrigerator ice dispenser was evaluated by transient structural analysis, and an improved design to maximize the opening angle was obtained. The opening angle of the existing design was found to be 78% of the upper limit. Several design modifications were proposed and analyzed to examine the effects of the design factors on the opening angle. As a result of the design modifications, the opening angle was improved by changing the lever material to a material with a high elastic modulus, moving the position of the support to the motor side, or increasing the lever shaft diameter. Considering the manufacturing cost of the new design, the design modification changing only the lever material was found to be the best because it does not require a change in the structure of the ice dispenser case. In conclusion, the opening angle can be improved by up to 95% of the upper limit value if the lever material is changed to an aluminum alloy. The methods and results presented in this study were found to be of great help in designing the duct cap assembly structure to facilitate the discharge of ice.

• Journal of Korea Water Resources Association
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• v.55 no.1
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• pp.99-109
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• 2022

This study was intended to suggest the applicability of stepped boulder fishway using the concept of traditional boulder weir, focusing on the problems of existing concrete pool-and-weir fishways installed in mountain streams. To achieve this purpose, a stepped boulder fishway was designed and constructed as a pilot project in consideration of ascending capacity of the selected target fishes. Under the given discharge conditions, the hydraulic characteristics of the fishway were investigated in the field, and the characteristics and ascending capacity of the fishes were compared and analyzed. The fishway had a short length and steep slope, but the mean drops between each baffle were the range of 0.15 to 0.29 m, and this range satisfied the limit condition of about 0.40 m, which was in the limit of the drop that target fishes can ascend. The mean velocities of each baffle and pool were 0.82 to 0.87 m/sec and 0.13 to 0.24 m/sec. This result satisfied the conditions of burst speed (10 to 30 times of body length) and mean velocity of the resting pool (7 to 25% of burst speed) for target fishes. Since the bottom surface of the pool formed of boulders had a gentle reverse slope and rotational flow did not occur, the efficiency of fishway can be increased, and it will also be possible to solve the maintenance problem by flushing bed materials.

• Journal of Korean Society on Water Environment
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• v.35 no.6
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• pp.497-509
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• 2019

After the Total Maximum Daily Loads(TMDLs) was applied, it became beyond the limit of concentration management. However, it does not adequately reflect the characteristics of various watersheds, and causes problems with local governments because of the standard flow set. Thus, in this study, the Han River system is organized into four groups in estimating the Pollution Contribution by applying the Flow Duration Curve(FDC) created by the daily flow of data from the HSPF. And the method of this study is expected to be valuable as basic data for the TMDLs. As a result, Group I contains the main watersheds with no large hydraulic structures and tributary watersheds. There is no specificity in the FDC and the Pollution Contribution is estimated as rainfall runoff. Group II contains watersheds near the city where the FDC is maintained above a certain level during the Low Flow Conditions and the Pollution Contribution is estimated as the discharge flow of large scale point pollution facilities. Group III contains the main watersheds in which the large hydraulic structures are installed and FDC is curved in the Low Flow Conditions. So the Pollution Contribution is estimated as the water quality of the large hydraulic structures. Group IV contains the upstream in mainstream watersheds in which the large hydraulic structures are installed and the FDC is disabled before the Low Flow Conditions. As the flow is concentrated in the High Flow Conditions, the non-point pollution sources are estimated as the Pollution Contribution.

• Journal of Korean Society on Water Environment
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• v.20 no.2
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• pp.110-119
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• 2004

The combination of biological and physical/chemical technologies is a promising technique to reduce highly concentrated pollutants in livestock wastewater. It is suggested to treat livestock wastewater efficiently as follows: firstly, biodegradable organic matters, nitrogen and some of phosphorus should be removed by a biological treatment process and then residual non-biodegradable organic matters, color and phosphorus be eliminated by physicochemical technologies. In this study, therefore, the integrations of chemical coagulation, activated carbon adsorption, Fenton oxidation and ozonation were evaluated to provide appropriate post-treatment processes for biologically pre-treated livestock wastewater. After chemical coagulation followed by ozonation or Fenton oxidation process, the quality of treated wastewater could meet the discharge limit in Korea. However, a yellowish brown color still remained in the treated wastewater after a single method such as coagulation and Fenton oxidation was applied. The ozonation was found to be the most effective technology for the decolorization. Neither simple biological nor physicochemical treatment provides adequate decolorization and sufficient depletion of organics in livestock wastewater so far. Consequently, the integration of Fenton oxidation and ozonation with a biological treatment process is recommended to treat livestock wastewater in terms of removal efficiency.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.8
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• pp.22-29
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• 2006

According to the recent revision of KS on the basis of the IEC, equipotential grounding systems has been come into focus and the use of surge protective devices(SPD) has been increased radically in order to operate the power system stably. $Z_nO$ varistor with non-linear resistance, which has an outstanding voltage-current(V-I) characteristic, is mainly used in power system to limit surge voltage and divert surge current. $Z_nO$ varistors are packaged several types based on the circuit assembly to be connected to a.c. power line. When the user assemble the $Z_nO$ varistors into parallel or series circuit package, there are my things to be taken into consideration including functions and thermal stability because they are directly related to the safety. We compare stabilities of each assembly type by measuring residual voltage, discharge current, leakage current and surface temperature concerned to the protection performances between a single device with a 40[kA] of current capacity and parallel or series circuits type of varistor package.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.1
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• pp.15-22
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• 2009

This study reports the serial use of a 3-D hydrodynamic model, EFDC-Hydro and a dynamic water quality model WASP7.2 that are maintained by USEPA. The 48 km section of the Geum River downstream between Daechung Dam and Gongju was selected as a sample study site. Topographical information was used to accurately represent morphology of the study site and boundary conditions were derived from governmental databases including WAMIS by Ministry of Land and Ocean and WEIS by Ministry of Environment. EFDC-Hydro was successfully calibrated for observed water level and WASP was calibrated using monthly observed water quality data obtained from the above sources. It was found that the current water quality target of BOD for the Geum River-H point could not be met on monthly basis though every other tributary of the area would meet its own water quality target as assigned in Korean TMDL. This study proposed the new target BOD water quality for the Gabcheon and Mihocheon as 4.3 and 3.6 mg/l, respectively so that the Geum River-H point can meet the target. When Sejong City is constructed, it is estimated that effluent discharge limit of BOD must be less than 4.5 mg/l to meet water quality of the point. This study shows that it is possible to carry out more precise modeling considering both water movement and water kinetics by using EFDC and WASP simultaneously.