• 드라이브 ㆍ 컨트롤
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• 제20권4호
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• pp.71-79
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• 2023

In the field of agricultural machinery, various on-field tests are conducted to measure design load for optimal design of agricultural equipment. However, field test procedures are costly and time-consuming, and there are many constraints on field soil conditions due to weather, so research on utilizing simulation to overcome these shortcomings is needed. Therefore, this study aimed to model agricultural soils using discrete element method (DEM) software. To simulate draft force, predictions are made according to travel speed and compared to field test results to validate the prediction accuracy. The measured soil properties are used for DEM modeling. In this study, the soil property measurement procedure was designed to measure the physical and mechanical properties. DEM soil model calibration was performed using a virtual vane shear test instead of the repose angle test. The DEM simulation results showed that the prediction accuracy of the draft force was within 4.8% (2.16~6.71%) when compared to the draft force measured by the field test. In addition, it was confirmed that the result was up to 72.51% more accurate than those obtained through theoretical methods for predicting draft force. This study provides useful information for the DEM soil modeling process that considers the working speed from the perspective of agricultural machinery research and it is expected to be utilized in agricultural machinery design research.

• 전자공학회논문지S
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• 제34S권12호
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• pp.50-59
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• 1997

A wireless LAN medical information transmission system is useful for patients who need mobility in a local area environment. This paper proposes a method using WLAN(wireless local area network) and implements a stand-alone system with MAC(meidum access control) layer protocol referenced IEEE 802.11 draft standard. The system consists of a 8bit-microprocessor which handles media access control protocol and a WL100(GEC Plessey) chip which takes care of phsical layer specific routines and uses a RF module DE6003(GEC Plessey). The major features of the implemented system are the CSMA/CA protocol used a consecutive DATA-ACK trasmission method which yields more effective bandwidth allocation for asyncronous traffic transmission and the modified PCF protocol for time-bounded traffic transmission, which operates in ad-hoc network topology apart from IEEE 802.11 draft standard confirm PCF mode operate in infrastruture topology.

• 한국기계가공학회지
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• 제14권2호
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• pp.7-13
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• 2015

In this study, we developed a gear-type vane damper which replaces the link type through a proper gear design by means of a finite element analysis. We analyzed the fluid flow according to the amount of angular displacement. torque and backlash problems were addressed in conjunction with the pinion as a structural improvement of the forced draft fan (FD FAN). Through an environmental test. Also, results nearly identical to those in the test could be drawn when using a numerical method. Finally, we compared the gear driving result with simulation results. objective of the present study is to identify a nonlinear flow rate control method for a gear-type vane damper and to propose a damper shape which offers linear flow rate control. This study is related to the development of a gear-type vane damper of the change-link type in a forced draft fan.

• 한국생산제조학회지
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• 제19권1호
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• pp.134-139
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• 2010

In this study, we developed the gear type vane damper replacing the link type through gear design using Finite Element Analysis(FEA). FEA about the pinion and the vane shaft in the boss of gear type damper for quality improvement was accomplished. We analyzed fluid flow according to angular displacement. Catched the problem of the torque and backlash bring to the pinion as structure improvement of the forced draft fan(FD FAN). Finally, we compared the gear driving result with simulation. It is the objective of the present study to identify a nonlinear flow rate control of gear type vane damper and to suggest a damper shape with a linear flow rate control. This study is related to the development of gear type vane damper change link type in forced draft fan.

• 수산해양교육연구
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• 제5권2호
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• pp.138-146
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• 1993

In accordance with the establishment of 200 nautical miles EEZ regime as a customary international law since the mid - 1980s, the area of global high seas became reduced relatively. On the other hand, the importance of high seas fishing ground became serious for the distant-water fishing states like Korea. But it can be expected that international dispute on the jurisdictional problem of the fishing vessels engaging high sea fishery will occur frequently owing to institutional inertia of the UNLOS Convention on this matter. "The Draft Agreement to Promote Compliance with International Conservation and Management Measures by Fishing Vessels on the High Seas" as an international code of conduct for responsible fishing which was adopted by FAO in 1993 is providing the more consolidating and definiting rules for jurisdictional responsibility of flag states to make completion the loophole of the UNLOS Convention. As a precondition for the effective control and enforcement of activities of the fishing vessels engaging high sea fishery, the Draft Agreement is providing some articles allowing the flag states to hold the rights of granting nationality, fishery permission, fishery supervision and control with punishment for the fishing vessels entitled to fly their own flag. Accordingly it can be evaluated that this Draft Agreement does not deviate on the whole from the traditional practice and the basic legal principle of the UNLOS Convention.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.514-514
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• 2017

Floating breakwaters were treated as solid bodies without any perforation in previous studies. In this study, however, a floating breakwater is perforated to allow the partial absorption of the energy produced by incident waves and an air chamber is placed in the upper part to control the breakwater draft. A series of laboratory experiments for a floating breakwater installed with a mooring system are carried out. In general, a mooring system can be classified by the number of mooring points, the shape of the mooring lines, and the degree of line tension. In this study, a four-point mooring is employed since it is relatively easier to analyze the measured results. Furthermore, both the tension-leg and the catenary mooring systems have been adopted to compare the performance of the system. In laboratory experiments, the hydraulic characteristics of a floating breakwater were obtained and analyzed in detail. Also, a hydraulic model test was carried out on variable changes by changing the mooring angle and thickness of perforated wall. A hydraulic model was designed to produce wave energy by generating a vortex with the existing reflection method. Analysis on wave changes was conducted and the flow field around the floating breakwater and draft area, which have elastic behavior, was collected using the PIV system. From the test results the strong vortex was identified in the draft area of the perforated both-sides-type floating breakwater. Also, the wave control performance of the floating breakwater was improved due to the vortex produced as the tension in the mooring line decreased.

• 동력기계공학회지
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• 제14권5호
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• pp.30-35
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• 2010

Recently, the large capacity draft fans in power plants had been changed to variable speed type to educe the power consumption. But the fan experienced the unexpected vibration at specific speed regions. In this study, the high vibration frequency of the fan was confirmed and the natural frequency of the rotor were measured and analyzed by FEM programs. It was analyzed that the vibration was caused by the resonance at the frequency, 30.7Hz. So, the rotor vibration characteristic was changed by adjusting the distance between the shaft bearings. It was conformed the high vibration was disappeared over the all operation speeds.

• 패션비즈니스
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• 제1권3호
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• pp.95-102
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• 1997

This study is aimed for men's jacket draft not only to other style but also helping for men's jacket fits for trend by presenting the course to get a style we want by adding to the partial drafty changes in existing pattern of men's formal jacket selected two kinds of men's jacket style fit for 1997 S/S trend. In this 1997 S/S trend, the trend I of the characteristic formal jacket is a style slim expressed over the basic formal wear, and trend II of the characteristic casual jacket appears to women's wear that roundly expressed by collar line of V-zone returened back by the shoulder line of jacket made of a big diagonal wrinkled line of X-style in front centered around a button of center front line. In this study, it called that the existing traditional formal jacket of men is a A style of jacket and jacket style I, II is a jacket B, C style. Jacket A, B, C style, a distingtion in draft that added to make form an oblique wrinkled line of the X-shaped-making artificially to the front button line sharply distinguished by eyes will be come out by control of front neck width over the back neck width. According to this, we shall be found that place of front neck point is a cardinal point in draft that will be added any changes in a style of jacket.

• 제어로봇시스템학회논문지
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• 제7권1호
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• pp.1187-1195
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• 2001

This paper presents a sweeping path planning algorithm for an autonomous smearing robot. An automatic planner generates a sweeping path pattern by proposed five basic procedures. This algorithm rocog-nizes obstacle on the architectural CAD draft and generates subgoals as tracking points which executes the area filling task based on heuristic approach. A sweeping path is planned by sequentially connecting the track-ing points in such a way that(1) the connected line segments should not be crossed, (2) the total tracking points should be as short as possible, and (3) the tracking line should not pass through the obstacle, Feasibility of the developed techniques has been demonstrated on a real architectural CAD draft.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1433-1435
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• 2000

Currently KERI is participating a project whose goal is to develop the Korean High-Speed Train(KHST) with maximum speed of 350kph. KERI's responsibility is the electrical system engineering that includes engineering design of an on-board computer system for diagnosis and control of train set and electrical/mechanical devices. A system engineering approach of the design is performed in order to guarantee the passenger safety and economically viable train for on-board control system construction, operation and maintenance. This paper presents the draft engineering des on-board computer system that ensures the s and reliability of KHST. The draft is focuse network interfaced distributed processing system.