• Proceedings of the KOR-KST Conference
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• 1998.10a
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• pp.488-495
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• 1998

대도시지역은 인구와 경제활동의 밀집도가 매우 높은 지역이나 계속되는 교통혼잡의 가중에의한 신속한 물자이동의 제약과 화물작업을 위한 공간의 부족 등으로 인하여 원활한 수송활동과 물류활동을 제한하는 장애요인들이 화물의 이동에 비하여 많은 실정이다. 도시가 존속하고 생산활동, 소비활동을 하기 위해서는 원자재, 에너지, 제품 등이 도시내·외를 통해 생산부문간과 개인·집단간에 원활한 수송이 이루어져야 한다. 하지만, 서울과 같은 대도시는 우리 나라 전체 경제에 미치는 영향이 매우 큼에도 불구하고 급속하게 증가하는 승용차 위주로 교통소통, 교통체계개선(TSM), 도로망 구축 등의 정책이 시행되어 왔다. 대규모 물류이동이 필수적인 서울의 남대문시장, 동대문시장, 용산전자상가 등 오래전부터 형성되어 온 도심상가지역은 굳이 언급하지 않더라도 서울 근교 신도시에 점차 확산되고 있는 대형 할인매장 등의 유통업무지구, 대형 사무용 건물 등에 원활하고 적시의 수송지원을 위해서는 체계적이고 합리적인 물류체계와 화물시스템 못지 않게 그에 따른 도로의 기하하적 구조나 화물차량을 고려한 신호체계 등이 필요하다. 따라서, 본 연구에서는 일반적인 도시 TSM기법 중에서도 화물차량 위주의 TSM기법에 중점을 두고 대도시에 적용 가능한 도로상의 화물차량 소통기법을 연구하여 그 적용성과 기대효과를 살펴보는데 그 목적이 있다. 본 연구는 크게 도시외곽을 경유하는 화물차량에 관한 도시외곽 화물 TSM 기법과 도시내 통과차량 소통기법, 주·정차 및 조업차량관리기법의도시내 화물TSM 기법으로 구성되어 있다. 도시외곽 화물 TSM 기법의 주내용은 신호체계 개선과 도로의 기하구조 개선 등이며, 도시내 화물 TSM 기법은 화물차량의 도시내 교통소통 기법과 화물차량의 주·정차 관리 및 조업차량 관리에 대한 연구를 수행한다. 대부분의 TSM 개선방안의 시행주체가 경찰청과 시이므로 본 연구의 결과는 도시의 원활한 화물교통소통을 위하여 적용가능할 것으로 예상된다.

• Journal of Environmental Impact Assessment
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• v.23 no.5
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• pp.364-378
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• 2014

Ecological Footprint (EF) in Korea has increased steeply over the past 50 years and, thus, the overshoot. It has been known that the main causes of the overshoot are population growth and the increase of the consumption intensity per person. In this study, the EF trend in Korea is analyzed for the past 50 years and it is found the major cause of the rapid increase of EF in Korea is the increase of the consumption intensity per person. Among the sectors of the consumption, Carbon Footprint (CF) from the energy consumption and Grazing Land Footprint and Fishing Grounds Footprint from the protein consumption are the major players for the increase. It is also found that if current trend of the EF per person would be maintained until 2060, EF in Korea would be expected to increase also continuously, despite of the decrease of the population from 2031. Therefore, the direction of the environmental management should be considered for inducing the change of the individual consumption patterns and the behavioral changes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10B
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• pp.973-980
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• 2009

Many studies which have been done for efficient installation and management of wireless sensor networks (WSN) include energy savings, key managements and sensor deployments. Sensor deployment problem is one of the most important and fundamental issues among them in that the topic is directly related with the system cost and performance. In this paper, we suggest a sensor deployment scheme that reduces the system cost of WSN while satisfying the fundamental system requirements of connectivity between sensor nodes and sensing coverage. Using graphical information system(GIS) which contains region-dependent information related with connectivity condition, the initial positions of sensors in the procedure simulated annealing (SA) are determined. The GIS information helps in reducing system cost reduction not only at the initial deployment of SA but also at the final deployment of SA which is shown by computer simulations.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.11
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• pp.601-611
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• 2002

As resent trends in structural construction have been to build taller and larger structures than any time in the past, they have had high flexibility and low damping that can cause large vibration response under severe environmental loading such as earthquakes, winds, and mechanical excitations. The damper with mass and sqring is one aproach to safeguarding the structure against excessive vibrations. In this paper, a large capacity hybrid-type linear motor damper(LMD) was designed and fabricated for the application to the vibration control of a large building structure model. It has been designed to be able to move the damper mass, 1,500 kg up to ${\pm}250mm$ strokes at the first mode natural frequency of the building structure model, ${\pm}0.51Hz$. Linear motor is consisted of the fixed coil and the movable NdFeB permanent magnets field part. The PM field part composed magnet modules and iron yoke, is the damper mass itself, 1500kg. LMD therefore has a simplified structure and requires a few elements in the driving system, being compared with a rotary motor damper and a hydraulic damper. However, the manufacture of large PM linear actuator is difficult because of the limit of PM size and the attraction and repulsion at the assembly of PM. Therefore, large damper system is manufactured and tested for dynamic characteristics and frequency response.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.5
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• pp.241-248
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• 1999

Recently, many linear motion generators and motors are rapidly finding applications that ranges from short stroke linear motion vibrators, such as dynamic cone type loudspeakers to stirling engine driven linear reciprocating alternators, compressors, textile machines etc. The stroke-length may go up to 2m, and the maximum speed is in the range of 5 to 10m/s with oscillating frequency as high as 15 kHz. Therefore, the linear oscillating actuators(LOAs) may be considered as variable speed drivers of precise controller with stoke-length and reversal periods during the reciprocating motion. In this paper, the design, fabrication, experiments, and extraction of control parameters of a moving coil type LOA for driving of linear reciprocating motion control systems, are treated. The actuator consists of the NdFeB permanent magnets with high specific energy as the stator produced magnetic field, a coil-wrapped nonmagnetic hollow rectangular bobbin structure, and an iron core as a pathway for magnetic flux. Actually, the design is accomplished by using FEM analysis for the basic configuration of a magnetic circuit, and characteristic equations for coil design. In order to apply as the drivers of a linear motion reciprocating control system, the control parameters and circuit parameters, such as input voltage-stoke, exciting frequency-stoke, coil inductance and so on, are extracted from the analysis and experiments on concerning a fabricating LOA.

• Nuclear Engineering and Technology
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• v.27 no.1
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• pp.74-83
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• 1995

The accurate determination of the fast neutron flux/fluence onto the pressure vessel is an essential part of the reactor pressure vessel surveillance program. It has been reported recently that the iron cross section data in ENDF/B versions III through V might underestimate the flux/fluence of fast neutrons in steel structures such as reactor pressure vessel. In this study, for the comparison of iron data of ENDF/B-IV and VI we produced two 47-group cross section sets, CXFe-IV and CXFe-Ⅵ, which are based on Yonggwang nuclear unit-3/4 model and the iron data of ENDF/B-IV and VI, respectively. A comparison was made of the results obtained from DOT4.3 calculation using CXFe-IV and CXFe-VI. From the results, it was found that the fast flux(E 〉 1.0 MeV), which is important for the pressure vessel embrittlement analysis, increases by about 7.6％ at the inner wall and 20％ at the outer wall of the vessel, if the iron data are used from ENDF/B-VI instead of ENDF/B-IV.

• Journal of the Korean association of regional geographers
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• v.11 no.6
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• pp.640-656
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• 2005

A chronic depression in the Korean economy, which depends mostly on imported oil, has been attributed partly to rising crude oil prices recently. Against the backdrop of these realities in Korea, Azerbaijan in the Caspian region, with vast oil and gas deposits, has been greeted enviously by some Koreans. Many transition economies, especially on the Caspian region trumpeted by the oil boom, however, are rich in natural resources, but the benefits of those resources are appropriated by the local elite in collusion with foreign companies. Azerbaijan, in particular, is dominated by a series of internal and external patronage networks. Foreign capital nourishes those networks surrounding President Aliev. Thus, the case of Azerbaijan shows that resource rents in the transition economies sometimes do not help in improving the living conditions of ordinary people. Rather rich resource rents turn out to be a major impediment to the emerging development of the transition economy, lessening the incentives to reform in the country. The result was the possibility of the so-called Dutch Disease, in which disproportionate growth in a certain energy sector tends to crowd out investment in other sectors of the economy.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.10
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• pp.581-586
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• 2002

To improve the current waveform of diode rectifiers, we propose a new operating principle for the voltage-doubler diode rectifiers. In the conventional voltage-doubler rectifier circuit, relatively large capacitors are used to boost the output voltage, while the proposed circuit uses smaller ones and a small reactor not to boost the output voltage but improve the input current waveform. A circuit design method is shown by experimentation and confirmed simulation. The experimental results of the proposed diode rectifier satisfies the harmonic guide lines. A high input power factor of 97(%) and an efficiency of 98[%] are also obtained. The new rectifier with no controlled switches meet the harmonic guide lines, resulting in a simple, reliable and low-cost at-to dc converters in comparison with the boost-type current-improving circuits. This paper proposes a nonlinear impedance circuit composed by diodes and inductors or capacitors. This circuit needs no control circuits and switches, and the impedance value is changed by the polarity of current or voltage. And this paper presents one of these applications to improve the input current of capacitor input diode rectifiers. The rectifier using the nonlinear impedance circuit is constructed with four diodes and four capacitors in addition to the conventional rectifiers, that is, it has eight diodes and five capacitors, including a DC link capacitor. It makes harmonic components of the input current reduction and the power factor improvement. Half pulse-width modulated (HPWM) inverter was explained compared with conventional pulse width modulated(PWM) inverter. Proposed HPWM inverter eliminated dead-time by lowering switching loss and holding over-shooting.

• Journal of Digital Convergence
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• v.11 no.11
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• pp.37-52
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• 2013

Prior to full-scale implementation of smart grid, the Korean government is conducting a smart grid testbed in Jeju island. However, the participants of the ongoing program are skeptical about the success of the expansion of smart grid. The concern rises from various reasons; the limits of the Korean electricity market mainly led by both the government and KEPCO, high stability and reliability of the existing electricity grid, insufficient utilization of renewable energy, and public fear of raised electricity bills. Five key issues in regards to facilitating the Korean smart grid market are extracted and evaluated. The issues are conflict of interest among participants, the effect of introducing real-time pricing, lack of customer participation of demand response, and absence of business models.

• Journal of Korea Port Economic Association
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• v.26 no.2
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• pp.36-48
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• 2010

This primary purpose of this study is to suggest strategy a green-logistics strategy of Gwanyang bay area. The Green growth is the new growth concept based on the low carbon and environment-friendly industry. The new paradigm on the global economy growth requests a established logistics industry to be shifted into establishing the environment-friendly green logistics system. Some findings derided from this study are follows: Frist, in order to establish a environment-friendly green growth foundation, it is necessary to attract a green industry such as solar cell, wind force, hybrid car etc. Second, a green logistics system has to be established, including a green port strategy and reducing emission of carbon.