• Geomechanics and Engineering
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• v.18 no.3
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• pp.277-289
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• 2019

In this study, an innovative anchoring approach has been developed dealing with all relevant aspects in consideration of previous works. An ultimate pulling force calculation of anchor is presented from a geotechnical point of view. The proposed umbrella anchor focuses not only on the friction resistance capacity, but also on the axial capacity of the composite end structure and the friction capacity occurring around the wedge. Even though the theoretical background is proposed, in-situ application requires high-level mechanical design. Hence, the required parts have been carefully improved and are composed of anchor body, anchor cap, connection brackets, cutter vanes, open-close ring, support elements and grouting system. Besides, stretcher element made of aramid fabric, interior grouting system, guide tube and cable-locking apparatus are the unique parts of this design. The production and placement steps of real sized anchors are explained in detail. Experimental results of 52 pullout tests on the weak dry soils and 12 in-situ tests inside natural soil indicate that the proposed approach is conservative and its peak pullout value is directly limited by a maximum strength of anchored soil layer if other failure possibilities are eliminated. Umbrella anchor is an alternative to conventional anchor applications used in all types of soils. It not only provides time and workmanship benefits, but also a high level of economic gain and safe design.

• Journal of Korea Soil Environment Society
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• v.3 no.1
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• pp.75-81
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• 1998

In most of studies on solidification/stabilization with waste, small columns have been used to examinate adsorption or leachate. However, these experiments using small apparatus have been limited to apply with the field. In this study, considering an application to the field, a large Lysimeter(100cm$\times$100cm$\times$100cm) used for the simulation. Then, the open dumping waste was mixed directly with bentonite to simulate the stabilization of waste, environmental aspects and several basic tests. As a result, the concentration of heavy metals and contaminated substances changed with bentonite rate. Most of contaminated substances were decreased in leaching with increased mixing rate of bentonite. Especially, the concentration of CODcr removed 25~30%. Also, the residual soil in dumping waste produced approximately 80% of total volume by 40$\times$40mm screen.

• 전기의세계
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• v.22 no.1
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• pp.35-41
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• 1973

An automatic point traffic control method is recommended for more idealistic traffic flow over coarse road netowrks. The automatic control apparatus recommended, consists of a transceiver, amplifier, digital-to-analog converter, signal light controller for emergency and steady state, and digital counter as monitor. The transmitter sends a signal to the target vy means of Microwave-FM-CW and a diode detector picks up the echo signal. Thus the operation of the entire system will be carried out through an open loop state. Some factors necessary for an ideal detector system are rapid response, longevity and stability. An analytical method of the Doppler effect substitutes the conventional frequency deviation into the amplitude of detector output. The changing rate of amplitude is proportional to the voltage of the detector output. Some induced formula from Maxwell's radiation field theory ensures this new method, and, new method, and proves the fact with an experimental data presentation. Stability depends upon Klystron as an oscillator and a diode as a detector. the transceiver installation affects on the response and sensitivity of the system. In accordance with the detector output, several targets are easily classified by amplitudes on the scope. The traffic flow, i.e., target movement which is analyzed by the amplitude method, is shown through the scope and indicates it on the digital counter. The best efficiency for the amplitude analysis can be attained through use of an antenna having the highest sensitivity.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2008.03a
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• pp.164-164
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• 2008

The beach-chair traction position is designed to allow the use of traction while allowing the surgeon to orient the shoulder in an upright position and convert to an open procedure, if necessary. The patient is placed in the beach-chair position under general anesthesia. A three-point shoulder holder (Arthrex, Naples, Florida) is attached to the rail of the operating table on the same side as the surgeon, whereas it is placed on the side opposite the surgeon in the lateral decubitus position. A shoulder traction and rotation sleeve (Arthrex) are affixed to the arm following the manufacturer's instructions. Positioning the thumb toward the closed side of the sleeve ensures a field for the anterior portion of the rotator cuff and prevents the tendency of the suspension apparatus to place the arm in internal rotation. The arm is maintained in 30 to 40 degree abduction and 30 to 40 degree flexion by controlling the length and height of the bar and the location of the universal clamp. The universal clamp allows multiple planes of adjustment to control abduction and forward movement of the arm. The sleeve is attached to the longitudinal traction cable using a sterile hook, and a lateral strap is secured around the proximal portion of the sleeve to the overhead traction cable to ensure a field for glenohumeral reconstruction. The use of a lateral strap permits ideal shoulder positioning for improved access to the anterior and inferior glenohumeral joint. The lateral strap can be released or removed to widen the subacromial space during subacromial decompression or rotator cuff repair. A 10-lb weight is attached to the longitudinal traction cable for an average-sized person.

• Journal of the Korean earth science society
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• v.31 no.3
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• pp.276-287
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• 2010

The purpose of this study is to develop a measurement tool quantifying the degree of high school students' scientific experience. Based on previous studies, we divided the factors that compose school scientific experience into three categories: general activity experience, scientific inquiry experience and laboratory apparatus experience. While, outside of school scientific experience was divided into general activity experience, interesting activity experience and field trip experience. Items consisting each factor were selected from scientific experience measurement tools used in previous researches, most frequent answers showed in open questionnaire about scientific experiences, and exploratory analysis of textbooks. After the measurement tool developed by pilot-questionnaires and previous researches were preliminary tested and then was secondarily tested for a group of 413 high school students. The content validity and construct validity of the measurement tool was evaluated by two school teachers and two experts in science education and by factor analysis, respectively. The reliability of the tool was estimated with Cronbach Alpha. The results of validity and reliability revealed that the tool was appropriate for measuring scientific experience.