• Economic and Environmental Geology
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• v.27 no.6
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• pp.601-609
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• 1994

Uranium resources of Mongolia are generally confined to sediments deposited during Jurassic to Cretaceous volcanism. Territory of Mongolian uranium deposits is divided into four districts as follows; Mongol-Priargun, Gobi-Tamtsag, Hentii-Dauer, North-Mongolian. Potential uranium deposits were discovered by Airborne Gamma ray Spectrometric Survey(AGSM). One of them, Haraat deposit, which was interested to us, has been under detailed survey for exploitation by one of American companies, Concord company. The Erdes uranium mine is partly operated by about hundred Russian staffs at the open pit, while underground mining facilities such as the main hoist are almost closed. Ore minerals of the Erdes Mine are coffinite and pitchblende. Uranium content in ore ranges from 0.06% to 1%, averaging 0.2%. Ore reserves of uranium ore in the Dornod deposit including the Erdes Mine accounts 29,000 ton. It is reported that Uranium resources of Mongolia are 1,471,000 ton.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.974-976
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• 1993

A design method of three phase induction motors that have characteristics of low starting current and high starting torque is proposed. This design method is based on the traditional theory related to the skin effect and the gap saturation effect. The starting performances and the analysis method are explained in short. Finally, comparison of example design data on electric hoist motor with standard motor is shown.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.44-45
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• 2019

Tower cranes are essential equipments that play a key role in the overall process of large-scale construction projects, as well as high-rise apartments construction projects. Tower cranes hoist various loads near and over people, working in crowded environments, sometimes in overlapping work areas, and often under the constraints of time, budget, and labor. This work system further increases the safety risks of sites with inherently hazardous workplaces. The methodology of this research was based on a comprehensive inquiry of a team of experts, including safety managers and equipment managers of major construction companies and previous literature search. Due to the limited resources available to improve safety and prevent accidents, more attention should be paid to all parties involved in factors that have been evaluated to have a significant impact on site safety due to tower crane operations.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.555-557
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• 2019

본 논문은 고객 가치를 극대화한 솔루션 전용화를 통해 전략시장을 집중 공략하고, 제품 진입 영역 확대 및 고부가가치 시장 창출을 주도한 LS산전의 Application 전용 저압 드라이브 개발 현황에 관한 것이다. 다양한 지역별 & Application별 목표 시장 공략을 위해 대응한 사례인 북미 오일 Pump Jack, 북미 향 Hoist, 인도 직물 공장, 중동 엘리베이터, 국내 PVC 장판 생산용 Winder 시장 등의 분야에서 전용화 한 사례들에 대한 전반적인 내용을 설명한다. 이와 같은 글로벌 Application 분야를 발굴하여 신 성장 동력을 창출하고, 고부가 가치를 고객별로 맞춤형 최적 Solution 적용하여 LS산전의 드라이브 시장에서 경쟁력과 시장 점유율을 증대하고자 한 사항을 확인 해 볼 수 있다.

• Journal of the Korea Society for Simulation
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• v.28 no.4
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• pp.11-20
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• 2019

This paper presents a HILS(Hardware-In-the-Loop Simulation) approach for the verification of the OHT (Overhead Hoist Transport) controller in a semiconductor FAB. Since hundreds of OHTs can run simultaneously on the OHT network of a FAB, the full verification of the OHT controller is very essential to guarantee the stableness of the material handling system. The controller needs to fully consider not only normal situations but also abnormal situations that are difficult to predict. For the verification of the controller, we propose a HILS approach using a virtual environment including OHTs on a rail network, which can generate abnormal situations. The proposed HILS approach has been implemented and tested with various examples.

• Journal of Navigation and Port Research
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• v.29 no.3 s.99
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• pp.291-298
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• 2005

In this article. the specifications of a future container crane for a 18,000 TEU megaship are investigated After studying the transitions of containerships through the past half century, the characteristics of the past and current container cranes are outlined. together with various research trends throughout the world Upon these results, the size and performance of the container crane that will be used beyond the year 2014 are forecast. Specifically, the structure, trolley and hoist mechanism, control method, outreach. backreach, rail gage, loading capacity, stability, durability, and others are summarized.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1598-1611
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• 2016

In some special occasions with strict size requirements, such as mine hoists, improving the design accuracy of the forced-air cooling systems of NPC three-level inverters is a key technology for improving the power density and decreasing the volume. First, a fast power-loss calculation method was brought. Its calculation principle introduced in detail, and the computation formulas were deduced. Secondly, the average and dynamic power losses of a 1MW mine hoist acting as the research target were analyzed, and a forced-air cooling system model based on a series of theoretical analyses was designed with the average power loss as a heat source. The simulation analyses proves the accuracy and effectiveness of this cooling system during the unit lifting period. Finally, according to an analysis of the periodic working condition, the maximum power-loss range of a NPC three-level inverter under multi cycle operation was obtained and its dynamic power loss was taken into the optimized cooling system model as a heat source to solve the power device damage caused by instantaneous heat accumulation. The effectiveness and feasibility of the optimization design based on the dynamic power loss calculation of the maximum power-loss range was proved by simulation and experimental results.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.1
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• pp.53-60
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• 2005

The wire rope of container crane is a important component to container transfer system and is used in a myriad of various applications such as elevator, mine hoist, construction machinery, and so on. If it happen wire rope failures in operating, it may lead to the safety accident and economic loss, which is productivity decline, competitive decline of container terminal, etc. To solve this problem, we developed the active and portable wire rope fault detecting system. The developed system consists of three parts that are the fault detecting, signal processing, and remote monitoring part. All detected signal has external noise or disturbance according to circumstances. Therefore we applied to discrete wavelet transform to extract a signal from noisy data that was used filter. As experimental result, we can reduce the expense for container terminal because of extension of exchange period of wire rope for container crane and this system is possible to apply in several fields to use wire rope.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2591-2593
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• 2005

본 연구는 물체의 좌우측 상단에 연결된 와이어로프를 모터 및 드럼을 통하여 감아 올리거나 내려 놓는 과정에서 물체가 수평상태를 유지하여 이동될 수 있도록 Two Motor-Two Drum 형식의 권양기를 제어 하는 권양기의 밸런스제어장치에 관한 것이다. 본 연구에 Two Motor-Two Drum 형식의 권양기 제어장치에 있어서, 물체의 상단에 연견된 일측 와이어로프와 타측 와이어로프의 이동길이를 실시간으로 검출하는 와이어로프 이동길이검출부와, 이 와이어로프 이동길이검출부를 통하여 검출되는 일측 와이어로프와 타측 와이어로프의 이동길이를 비교하여 물체의 기울어진 좌 우 편차를 검출하는 편차검출부와, 이 편차검출부를 통해 검출되는 좌우 편차를 제거하기 위하여 일측 또는 타측 와이어로프가 감겨있는 드럼을 회전시키는 모터의 구동속도를 조절하여 물체를 수평상태로 보정하는 밸런스제어부로 구성 되어 있다.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.268-270
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• 1995

In crane drives, DC motor has been most widely used due to simple control characteristic and favorable transient behavior. Nowadays, however, the squirrel cage induction motor is known as an attractive candidate due to elimination of all sliding electrical contacts, resulting in an exceedingly simple and rugged construction. Especially, in hoist application, the smooth torque control and four quadrant operation are essential. In this paper, an operation of dual inverters with common DC bus fed by vector controlled induction motor is described. Single DSP is employed as a main processor to control dual inverters and communicates each input/output signal with PLC. As well as giving a detailed expression, full simulation and experimental results are presented.