• 전기의세계
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• v.20 no.4
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• pp.31-36
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• 1971

This is intending to introducdine the pipe type 161KV underground cable system in Capital City of Seoul which will be constructed in 1972 or 1973 by Korea Electric Co using the AID loan and Won currency. In order to make readers to have an easy understanding and a clear view of underground cable transmission line, the first part will be for the introduction of the description on future underground cable system by Mr. E.H.F inch appeared on 1969 Sept. Consulatant Engineer. the second part will introduce our 161KV underground cable system in Seoul and it's feasibility study, and the third part will mention calculation methods of electrical properties of pipe type cable and the results of calculation of our own system.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.665-672
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• 2002

In this paper, the utilization of waste foundry sand produced in the molding process is studied as a backfill material for underground electric utility systems such as concrete box structures and pipe lines for power supply. The physical, chemical and thermal properties for waste foundry sand are investigated for mechanical stability, environmental hazard and power transmission capacity. Also its properties are compared with the natural river sand. The test results show that waste foundry sand can be utilized for underground concrete box structures as a backfill material; however, it can not be applied to underground pipe lines due to high thermal resistivity or low power transmission capacity.

• 전기의세계
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• v.21 no.1
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• pp.22-30
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• 1972

가공송전선의 전기특성은 corona손등 특수한 것을 제외하고는 이론공식에 의하여 비교적 간단히 그리고 정확한 수치를 구할 수 있었으나, 지중선의 전기특성은 도체의 근접효과, 절연체의 유도손, pipe내의 과류손, 그리고 토양의 방열효과등이 그 영향을 미치므로 간단치 않고 따라서 그 이론공식도 대단히 복잡하다. 그러나 본문에서는 관계기술서적에서 필요부분을 초록하여 우리나라에서 시초로 사용될 154KV pipe type cable의 선로정수 허용전류 등 그 전기특성을 산출하는데 필요한 수식을 소개하고, 그 계산도 실시하고저 한다.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.3
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• pp.341-348
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• 2007

The efficiency of powdered activated carbon (PAC) for removing taste and odor (T&O) in drinking water supplies is dependent on the contact time, quality of mixing, and the presence of competing compounds. All of these are strongly influenced by the stage in the treatment process at which the PAC is added. In conventional water treatment plants (WTPs), PAC is commonly added into the rapid mixing basin where chemicals such as coagulants, alkaline chemicals, and chlorine, are simultaneously applied. In order to prevent interference between PAC and other water treatment chemicals, alternative locations for addition of PAC, such as at transmission pipe in the water intake tower or into a separated PAC contactor, were investigated. Whatever the location, addition of PAC apart from other water treatment chemicals was more effective for geosmin removal than simultaneous addition. Among several combinations, the sequence 'chlorine-PAC-coagulant' produced the best result with respect to geosmin removal efficiency. Consequently, when PAC has to be applied to cope with T&O problems in conventional WTPs, it is very important to prevent interference with other water treatment chemicals, such as chlorine and coagulant. Adequate contact time should also be given for adsorption of the T&O compounds onto the PAC. To satisfy these conditions, installation of a separated PAC contactor would be the superior alternative if there is space available in the WTP. If necessary, PAC could be added at transmission pipe in the water intake tower and still provide some benefit for T&O treatment.

• Journal of the Korean Society for Advanced Composite Structures
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• v.4 no.3
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• pp.38-44
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• 2013

Glass fiber reinforced plastic (GRP) pipes buried underground are attractive for use in harsh environments, such as for the collection and transmission of liquids which are abrasive and/or corrosive. In this paper, we present the result of investigation pertaining to the structural behavior of GRP flexible pipes buried underground. In the investigation of structural behavior such as a ring deflection, experimental and analytical studies are conducted. In addition, vertical ring deflection is measured by the field test and finite element analysis (FEA) is also conducted to simulate behavior of GRP pipe buried underground. Based on the results from the finite element analyses considering soil-pipe interaction the vertical ring deflection behavior of buried GRP pipe is predicted. In addition, analytical and experimental results are compared and discussed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2641-2646
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• 2009

The more growing on home automation system at automatic control, the more efficiency required for energy consumption and for recycling energy in near future. Heating is essential in general apartment. Heating method is two types in apartment. One uses electricity, and other one uses warm water. If use electricity, is not efficient by rise of electric charges. But, It can reduce much in expense aspect, if use warm water. When use warm water, temperature of warm water is not equal from all pipe parts. Therefore, indoor tempera can be unequal with set point. Solution of these problems is as following. Temperature sensor in warm water attach pipe. The measured temperature transmits by real time. Temperature of warm water controls in receiver side. In this paper, we propose an automatic temperature transmission system for the heating pipe at home, that is a low-power based, and supply the energy source from a small AC motor resided in bottom cement mortal. The proposed system is used in power mechanism from a collision process of water-jet using propeller water-difference and also designed a CPU module by Atmega8 at ATMEL co., Inc. and a communication module by CC1020 at Chipcon co., Inc.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.751-758
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• 2002

Boreholes that are drilled in soft or unconsolidated materials such as gravels and coals are prone to collapse. To maintain the hole, some kinds of casing pipes are needed. If thereby a plastic pipe e.g. PVC is used for the casing, Televiewer tool is still capable of detecting structural features such as fractures in the borehole wall behind the pipe, whereas other borehole-imaging logging devices such as BIPS (Borehole Image Processing System) and FMS(Formation Micro Scanner) won't provide any information about that. Televiewer's primary component is a piezoelectric transducer centered in the hole. It acts as both a transmitter and receiver, and sends an ultrasonic beam. That is reflected, in the same manner as the seismic wave propagation, from the both sides(inner and outer surfaces) of the casing pipe, transmits through the pipe and then reflected from the borehole wall. With an appropriate choice of time-windowing, it is possible to capture the returning signals from both the borehole wall and the outer side of casing pipe as well. A suite of laboratory tests were performed on various physical models composed of plastic pipes with different diameters. Although the amplitudes of returning signals were reduced to about half the usual value due to the transmission loss, the dynamic range of Televiewer tool was sufficient to observe the structural features behind the casing pipe. Besides, several representative case studies at various research areas in our country are presented. The results demonstrate the usefulness of the transmissivity of Televiewer acoustic km, which will assist in further structural interpretation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.733-735
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• 2014

The paper deals with the energy transmission ratio of the elastic waves obliquely transmitting through a plate and a pipe. The incidence angle corresponding to the maximum transmission was determined theoretically and considered in the design of ultrasonic transducers for flow velocimetry. Experimentally-obtained transmission ratios were compared with and confirmed the theoretically-calculated results.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.2
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• pp.124-132
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• 2015

The paper deals with the energy transmission of the elastic waves obliquely transmitting and refracting through a plate and a pipe. By calculating the transmitting ratio depending on the incidence angle, the angle corresponding to the maximum transmission was determined theoretically and considered in the design of ultrasonic transducers for flow velocimetry. Experiments were carried out by using prototypes of the transducers. Experimentally-obtained transmission ratios were compared with and confirmed the theoretically-calculated results.

• Journal of Power System Engineering
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• v.18 no.5
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• pp.100-105
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• 2014

It has been previously reported that in principle sludge and blockages can be detected and even characterized by using guided ultrasonic torsional waves, based on an idealized model in which the sludge layer was simplified in terms of geometry and material properties. The work revealed that the presence of a layer inside a pipe scatters the guided wave propagating in the pipe and both the reflection and transmission of the guided wave can be used to effectively detect and characterize the layer. This paper proceeds the work by taking into account more realistic sludge characteristics, including irregular circumferential profiles of the sludge layer and imperfect bonding state between the sludge and the pipe. The influence of these issues is investigated to identify the critical factors that influence the detection and characterization capability of the two measurements.