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      • 政治資金制度에 관한 硏究

        이재옥 성균관대학교 2005 국내석사

        RANK : 247631

        The politics of the current representative state is mainly carried into effect by a political party. Likewise, as the importance of a political party has been emphasized, it's essential to secure political funds to carry out major functions of a party and improve growth of it. There is a necessity for a party to procure political funds to initiate a responsible political management and a policy for the benefit of the people. Moreover, a political party is heavily dependent on political funds as the driving force of political activities to encourage people to speak their political mind by nominating a candidate. But the fact that a party has no choice but to supply what is needed through an external income except for the internal means of raising money, party expenditure becomes an issue. Hereupon, the present paper aims to examine size and scope of the political funds actually spent on political activities, and under assumption that demand and supply of the political funds must be properly established, the paper analyzes procurement and spending of the political funds so that scheme for improving the current political funding system geared to meet the reality of our nation's politics. Some of the problems with Korean political funding system is that the central party is excessively large and that most of the funds is spent on election campaigning. The procurement of the political funds depends heavily on government subsidy and on political donation from supporters. The party member fees, one of the political parties' main source of party income, takes only a minimal percentage of the total funds for political activities causing parties's financial independence at a very low level. Furthermore, imbalance of funds available for the ministerial party and the opposition party is quite large and this is due to unreasonable distribution policy of the government subsidy between the political parties and also due to large difference in political donations from supporters to the ministerial and the opposition party. In proposing ways to improve the political funding system that is ridden with above mentioned problems, the governing by the political parties can be improved if should the employment of the funds be reduced and also if should political activities be centered around the national assembly. The political donations from the supporters and the government subsidy for the political funds call for reforms so that their original purpose for introduction in the first place can be fully realized.

      • 大形 디젤엔진의 構造應力解析 및 베어링 캡의 最適化 設計

        李在玉 忠南大學校 大學院 2008 국내석사

        RANK : 247631

        The heavy duty diesel engine must have a large output for maintaining excellent mobility. In this study, a three dimensional finite element model of a heavy-duty diesel engine was developed to conduct the stress analysis. The FE model of the heavy duty diesel engine main parts consisting with four half cylinder was selected. The heavy duty diesel engine parts included with cylinder block, cylinder head, gasket, liner, bearing cap, bearing and bolts.The loading conditions of engine were pre-fit load, assembly load, and gas load. As the results of structural analysis, because the stress values of cylinder block and bearing cap did not exceed the allowable strength of material the basic design could be satisfied. But on the part which contacts with cylinder block and bearing cap the stress value exceeded the allowable strength of material. In order to decrease the stress at that part, it was optimized with parametric study.The conclusions are described as follows;(1) The displacement of bearing shell must be within the oil clearance for efficient performance of engine and satisfied the condition of oil clearance under gas load.(2) As the results of structural analysis, the basic design could be satisfied because the stress values of cylinder block, cylinder head and bearing cap did not exceed the allowable strength of material.3) The stress value of bearing cap locally exceeded the allowable strength of material under gas load on the contact area of cylinder block and bearing cap. When the areas of cylinder block were larger than those of bearing cap, the level of stress was decreased with constant area.4) The more the contact areas of cylinder block and bearing cap were increased, the more stress values were decreased. When the height of bearing cap was 50 mm, it was the best design for the safety factor as 1.4.

      • 低溫 플라즈마와 NH₃SCR 複合工程의 低溫 DeNO 特性 硏究

        이재옥 忠南大學校 2008 국내박사

        RANK : 247631

        It is nowadays worldwide accepted that primary techniques are not sufficient for control of pollutants emitted from vehicles, and thus exhaust after-treatment systems are needed in order to comply with the current and the forthcoming emission standards. Recently, selective catalytic reduction (SCR) assisted by nonthermal plasma has been widely proposed as a promising deNOx technique for diesel applications.An experimental study on a combined deNOx process of nonthermal plasma and NH₃SCR, which can be operated under low temperature conditions, i.e., 150∼200 ℃, has been conducted. The type of nonthermal plasma reactor was dielectric barrier discharge (DBD). SCR catalyst used in this work is monolithic V₂O_(5)-WO₃/TiO₂catalyst of which reducing agent is ammonia.In the fore part of the present study, several technical issues, which are feasibility of fast SCR reaction, the effect of NO₂/NOx ratios in fast SCR reaction, the effect of water vapor contained in the reactant, production of ammonium nitrate salts under low temperature conditions, the effects of hydrocarbon and CO on the process and effect of aldehydes produced from HC (C₃H_(6)) in the course of low temperature oxidation were investigated with a lab-scale experiment.In the aft part of this work, NH₃SCR assisted by plasma oxidation is presented. In this part of work, that has been carried with a real 2,000 cc diesel engine, feasibility of plasma combined SCR process in real engine condition has been investigated with focus on the following parametric point of view. 1) The effect of HC addition as reacting gas that can affect the input energy of plasma reactor in fast SCR process. 2) Emission characteristic, especially NO to NOx ratio, according to the engine condition. 3) Comparison of deNOx efficiencies for standard SCR and fast SCR with diesel exhaust. The results are as following;Test results show that in the fast SCR reaction, the condition for equimolar amounts of NO and NO₂in the reactants, plays a dominant role in deNOx performance under relatively low-temperature conditions, i.e., 150∼200 ℃. and deNOx rate in the fast SCR reaction recorded higher value than that of conventional SCR reaction.The deNOx efficiencies along with the NO₂/NOx ratios makes asymmetric parabola curve. The highest deNOx efficiency or vertex of the parabola is observed when NO₂/NOx ratio is 0.5. The asymmetricity is attributed to the formation of ammonium nitrate that is formed in the condition of gas temperature lower than 150 ℃. The test showed that pre-oxidation step for the conversion of NO to NO₂is necessary for the fast SCR reaction, and the appropriate ratio of NO₂/NOx ranges from 0.3 to 0.5.When the water vapor exists in the reacting gases, the deNOx efficiency is lowered by 10~20% along with all the NO₂/NOx ratio conditions. Addition of hydrocarbon (C₃H_(6)) on the exhaust gas is effective for the reduction of the specific energy density (SED) applied to the plasma reactor.The oxidation of NO to NO₂by nonthermal plasma is useful for the control of NO₂fractions in NOx. The role of fast SCR reaction, however, decreases when C₃H_(6) is supplied to the process. here, C₃H_(6) is selected to simulate HC species in diesel exhausts. Followings are conclusions from the results: (1) C₃H_(6) promotes production of aldehydes in the process by nonthermal plasma. (2) production of aldehyde reduces fraction of NO₂leading to a diminished role of fast SCR reaction. This reduction in NO₂is predominant when water vapor is not added to the test gases. (3) decreased role of the fast SCR reaction is recovered when water vapor is supplied in the reactants, and the optimal NO₂fraction for highest deNOx rate is changed to higher value (greater than 0.5), this effect of water vapor should be counted in the application of plasma combined SCR process in diesel exhaust.The technique of NH₃SCR (selective catalytic reduction) assisted by plasma oxidation has been applied to a real 2,000 cc diesel engine. The plasma combined deNOx process consists of two steps. in the course of the first step, 50% of emitted NO from the engine is oxidized to NO₂by plasma process. and during the second step NO and NO₂are simultaneously reduced to N₂and H₂O by NH₃SCR process.Process cost can be reduced by supply of additional HC (C₃H_(6)). NO₂/NOx ratio in low rpm and low load condition ranges about 10-40% resulting less power consumption in oxidation process. The engine test results showed that the deNOx rates of the present combined process are higher than those of conventional SCR process by 20%. Such a high performance of the combined process is noticeable especially, when the exhaust temperature are relatively low, i.e., 180∼220 ℃.Considering that the emission in low rpm and low load condition has rather high NO₂/NOx ratio and UHC therein, fast SCR process that requires NO₂/NOx ratio of 0.5 for the cost down of the operation has high feasibility of application. and here, the nonthermal plasma process finds its place of application substituting conventional oxidation catalysts that requires rather high temperature for activation and light off.All of the results reported in this work is applicable in deNOx process of various type of emissions. and further work will be focused on the reduction of operating cost of the plasma oxidation process in high rpm and high load condition.

      • Ca2+ 조절에 의한 세포 노화 형질의 감소 효과

        이재옥 서울시립대학교 일반대학원 2013 국내석사

        RANK : 247631

        사람의 정상적인 섬유아세포는 in vitro에서 무한정 분열하지 않고 제한된 횟수의 세포 분열 후에 replicative senescence 상태에 들어간다. 암세포의 경우에는 화학적 약물을 이용하면 induced senescence 상태에 들어가게 된다. 이 두 가지 경우 모두 lysosome 함량의 증가와 residual body의 증가, SA-β Gal 활성의 증가, mitochondrial membrane potential이 감소하는 등의 노화 형질을 나타내는 것으로 밝혀져 있다. 노화세포에서 lysosome은 biogenesis에 의해 증가하며 Transcription factor EB(TFEB)의해 biogenesis는 조절된다. 또한 노화세포에서 증가한 lipofuscin의 경우도 TFEB가 Ca2+의 수준을 조절함으로써 세포 내에 축적되어 있는 lipofuscin을 제거한다는 것이다. 그래서 본 연구에서는 노화세포 내에서 활성을 가지는 TFEB가 Ca2+ 수준을 조절을 해주게 되면 증가한 lipofuscin을 감소시킬 것이라 생각하고 세포 내 Ca2+ 수준이 증가된 상황에서 세포 노화 형질들은 어떻게 변할 것이며, 노화세포에서 TFEB가 어떤 역할을 할 것인지에 대해 조사하였다. Ionomycin이라는 약물을 처리 하고 세포 내의 Ca2+ 수준 변화를 관찰한 결과 20분 만에 Ca2+ 수준이 최대로 증가하였다. 만약 lysosome의 exocytosis가 일어난다면, lysosome의 함량이 감소할 것이라 보고 실험한 결과 4㎛ ionomycin의 경우에서 감소한 것이 관찰되었다. 그렇다면 감소한 lysosome의 함량만큼 lysosome의 효소 활성도 변할 것인지 관찰하였는데, 효소의 활성은 in solution과 in situ assay 두 가지 경우에서 다른 결과를 보였다. 다음으로 TFEB가 과발현된 노화세포에서의 Ca2+ 수준의 변화는 정상 세포에서의 변화와 동일하며 증가한 lipofuscin이 5㎛ ionomycin에서 감소되었다. 이 결과를 종합해볼 때 노화 상황에서 증가한 lipofuscin은 Ca2+ 수준에 의해 감소될 수 있으며 이는 노화 상황에서 증가하는 여러 가지 표현형들의 감소에 영향을 미칠 것으로 생각된다.

      • Observational Studies of CME-Driven Shocks and Their Associated DH Type II Radio Bursts Using Multi-spacecraft Data

        이재옥 경희대학교 대학원 2017 국내박사

        RANK : 247631

        In this thesis, we have studied shock signatures driven by solar coronal mass ejections (CMEs) and their associated deca-hecometric (DH) type II radio bursts using multi-spacecraft data in order to both understand CME-driven shocks and determine coronal electron density distributions (CEDDs) and source regions of DH type II radio bursts. Firstly, we have conducted a statistical investigation to determine whether or not the appearance of faint structures ahead of CMEs depends on their speeds. For this purpose, we use 127 Solar and Heliospheric Observatory/Large Angle Spectroscopic COronagraph (LASCO) front-side halo (partial and full) CMEs near the limb from 1997 to 2011. We classify these CMEs into two groups by visual inspection of CMEs in the LASCO–C2 field of view: Group 1 has the faint structure ahead of a CME and Group 2 does not have such a structure. We find the following results. (1) 87 CMEs belong to Group 1 and 40 CMEs belong to Group 2. (2) Group 1 events have much higher speeds (average = 1230 km s−1 and median = 1199 km s−1) than Group 2 events (average = 598 km s−1 and median = 518 km s−1). (3) The fraction of CMEs with faint structures strongly depends on CME speed (V_CME): 0.93 (50/54) for fast CMEs with V_CME ≥ 1000 km s−1, 0.65 (34/52) for intermediate CMEs with 500 km s−1 ≤ V_CME < 1000 km s−1, and 0.14 (3/21) for slow CMEs with V_CME < 500 km s−1. We also find that the fraction of CMEs with DH type II radio bursts is consistent with the above tendency. Our results indicate that the observed faint structures ahead of fast CMEs are most likely an enhanced density manifestation of CME-driven shocks. Secondly, we have examined whether observational stand-off distance ratio, defined as CME stand-off distance divided by its radius, can be explained by bow shock theories or not. Among 535 SOHO/LASCO CMEs (from 1996 to 2015), whose speeds are greater than 1000 km s−1 and angular widths are wider than 60 ̊, we select 18 limb CMEs with the following conditions: (1) their Alfvenic Mach numbers are greater than one under Mann’s magnetic field and Saito’s density distributions; and (2) the shock structures ahead of CMEs are well identified. We determine observational CME stand-off distance ratios by using brightness profiles from LASCO-C2 observations. We compare our estimates with theoretical stand-off distance ratios from gasdynamic (GD) and magnetohydrodynamic (MHD) theories. Major results are as follows. Under the GD theory, 39 % (7/18) of the CMEs are explained in the acceptable ranges of adiabatic gamma (γ) and CME geometry. Under the MHD theory, all the events are well explained when we consider quasi-parallel MHD shocks with γ = 5/3. When we use polarized brightness (pB) measurements for coronal density distributions, we also find similar results: 8 % (1/12) under GD theory and 100 % (12/12) under MHD theory. Our results demonstrate that the bow shock relationships based on MHD theory are more proper than those based on GD theory to analyze CME-driven shock signatures. In last, we have determined coronal electron density distributions (CEDDs) by analyzing DH type II observations under two assumptions: DH type II bursts are generated by either (1) shocks at CME leading edges or (2) CME shock-streamer interactions. Among 399 Wind/WAVES type II bursts (from 1997 to 2012) associated with SOHO/LASCO CMEs, we select 11 limb events whose fundamental and second harmonic emission lanes are well identified. We determine the lowest frequencies of fundamental emission lanes and the heights of leading edges of their associated CMEs. We also determine the heights of CME shock-streamer interaction regions. The CEDDs are estimated by minimizing the root mean square error between the heights from the CME leading edges (or CME shock-streamer interaction regions) and DH type II bursts. We also estimate CEDDs of 7 events using polarized brightness (pB) measurements. We find the following results. Under the first assumption, the average of estimated CEDDs from 3 to 20 R_⊙ is about 5-fold Saito’s model (N_saito (r)). Under the second assumption, the average of estimated CEDDs from 3 to 10 R_⊙ is 1.5-fold N_saito (r). While the CEDDs obtained from pB measurements are significantly smaller than those based on the first assumption and CME flank regions without streamers, they are well consistent with those on the second assumption. Our results show that not only about 1-fold N_saito (r) is a proper CEDD for analyzing DH type II bursts, but also CME shock-streamer interactions could be a plausible origin for generating DH type II bursts.

      • 新羅의 弩 運用과 그 의미

        이재옥 경북대학교 교육대학원 2011 국내석사

        RANK : 247631

        The purpose of this paper, the basic structure and form of the Crossbow, starting with a review of the cognitive and the introduction of the Crossbow at the Silla period, and check the background, and became self-creation is to review the timing and the background. In addition, the Crossbow and my head to categorize the type and purpose, as well as being a weaponized Silla focused on the oar examined.Played by the mechanism as a weapon to shoot an arrow, has already appeared in the Warring States period, China was used as the main weapon. The Crossbow has a long range bow faster penetration is high.These play with the ability to enhance the variety of weapons will evolve.Nakrang playing in a country area around the excavation, and this also the first southern Woodwind Yeongcheon Yongjeon-ri's attention anger was excavated from tombs. Excavated Yongjeon-ri, the age of Crossbow-machine, I thought, as the late first century B.C. Silla, and at this point would have been aware of the presence Crossbow.When in the 4th century Goguryo southward policy and to the rigidity of the three kingdoms of Baekje escalating military confrontation between the sides are reinforced. Because of this, at the time of Silla had advanced weaponry from Goguryeo, you would like to receive weapons were aggressively. Therefore, accepting weapons from Goguryeo, Silla was the middle of the fourth century, about the time in the 5th century Silla who accept are estimated from the oars.Introduced through the process of these paddles in Silla, which leads to self- authoring stage, the mid-sixth century Silla King Jinheung case by making its own star on the paddle to the steps to install the above can be seen that development. Crossbow itself from this period include three major aspects of production in the background, was able to look at.First, the short-range distances from the aspect of the battle changes. Second, the type of battle field higher than the proportion of the temple. Third, the 6th century, the race centered period other regions are actively produced in the construction of acid. Thus due to the changes in a variety of combat environments with Crossbow can show that and therefore the weight.Silla's play can be categorized according to size and type, the intended use of each furnace is then divided by type. Silla also spread the oars and rowing in earnest efforts to operate as the main weapon will be war. The war was devastating, especially the Three Kingdoms unification king Munmu(文武王) is concentrated in the Crossbow operation. No paddles, including the existence of specialized producers to manage the Crossbow Tang' What is Labor that is being installed out his office, no private party adult Production Installation at this time Silla glimpse of rowing has been trying to concentrate that can be weaponized, is a big tree.Under this management, playing as a Goguryeo and Baekje Silla's main weapon in the battle, including the Tang(唐) and Silla victory would have been a big role to. After the unification of the Three Kingdoms of Silla after several externally achieved due to the deterioration of the military response relationships will be sought. As the military preparedness of these Crossbow to improve the performance, which it will visit and inspect, it was the Silla and the ongoing management of the oars can be seen that.

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