• 반도체디스플레이기술학회지
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• 제16권1호
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• pp.102-105
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• 2017

Currently, the size of the electronic device is in the nano area. In order to control the movements of these nanoscale devices, one should be able to understand the physical phenomena in the nano area. Recently, due to carbon nanotubes and mechanical outstanding electrical conductivity and mechanical characteristics of the carbon nanotubes and Graphene behaves to apply. Efforts have been active. There are various tubes with a radius of a in a compact mass in the form of a Multi walled carbon nanotubes in different between the radius. Van der Waals force can move smoothly without friction with each other by the nanoscale motor turning, using the properties, making. This is the lightest solids per unit area on the thickness is electrical atomic layer one of the substance and the electrical conductivity, the best material and mechanical characteristics are very much. Many studies because great is the ideal nanoelectromechanical device of material is being considered. In this study, electrical resonator for a new structure proposed and the nature and methodology would like to come up.

• ETRI Journal
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• 제28권5호
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• pp.545-554
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• 2006

A widely tunable multi-channel grating cavity laser is proposed and experimentally demonstrated. The device is implemented in Littman configuration with an echelle grating based on Rowland circle construction and realized by monolithically integrating all elements in an InP substrate. Lasing wavelength is selected by turning on an amplifier and the appropriate channel element in the array, and it is tuned by controlling light deflection electrically. The 6-channel device exhibits a tuning range of about 50 nm with a side mode suppression ratio of more than 30 dB. This is accomplished by adjusting the applied current of the dispersive element and phase control section.

• 한국산학기술학회논문지
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• 제3권1호
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• pp.38-43
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• 2002

본 논문은 자동으로 책장을 넘길 수 있는 장치에 대한 시스템 설계 및 제품개발에 관해 다룬다. 악보 또는 책을 손상시키지 않고 책장을 한 장씩 넘기기 위해 흡임모터를 이용했으며, 책장을 넘길 때 책을 고정, 흡입 그리고 책장을 넘기는 일련의 동작을 마이크로프로세서에 의해 다수의 모터를 이용하여 구현하였다. 기존 제품은 사전에 한정된 낱장들을 다수개의 넘김바에 끼워야 하는 반면 본 장치는 사전 작업이 필요 없이 자동으로 낱장들을 넘긴다. 제작된 결과물을 이용하여 실증실험을 통해 본 장치의 효용성을 입증하고자 한다.

• 한국정밀공학회지
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• 제29권2호
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• pp.129-138
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• 2012

In this study, three types of large scale multi-tasking machine tools together with core technologies involved have been developed and introduced; a multi-tasking machine tool for large scale marine engine crankshafts, a multi-tasking vertical lathe for windmill parts, and a large scale 5-axis machine tool of gantry type. Several special purpose devices has been necessarily developed for the purpose of handling and machining big and heavy workpieces accurately, such as PTD (Pin Turning Device) with revolving ring spindle for machining eccentric crankshaft pins, hydrostatic rotary table and steady rest for supporting and resting heavy workpieces, and 2-axis automatic swiveling head for high-quality free surface machining. Core technologies have been also developed and adopted on their detail design stage; 1) structural design optimization with FEM structural analysis, 2) theoretical hydrostatic analysis for the PTD and rotary table bearings, 3) box-in-box type cross-rail and octagonal ram design to secure machine rigidity and accuracy, 4) constant spindle rpm control against gravitational torque due to unbalanced workpiece.

• 한국추진공학회지
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• 제5권1호
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• pp.26-33
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• 2001

제트베인 추력편향장치는 노즐 뒤에 장착되어 노즐에서 분사되는 초음속 제트의 유동방향을 편향시킴으로써 하나의 노즐로 피치, 요, 롤 방향의 제어를 할 수 있는 장치이다. 제어력을 얻기 위해 초음속 유동중에 노출되어 있는 제트베인에는 열 및 공기역학적 하중이 작용하게 되며, 제트베인의 형상 및 편향각에 따라 나타나는 충격파 및 제트베인 상호 유동간섭으로 인해 비행 추력 손실 및 측력의 크기에 영향을 미치게 된다. 본 연구에서는 마하 2.88 노즐 중에 놓인 제트베인의 피치 및 요, 롤 방향의 특성을 규명하기 위해 6 종의 제트베인을 선정하고, 각 방향에 따른 제트베인 편향각 $0^{\cire}$~$25^{\cire}$ 범위에서 $5^{\cire}$ 간격으로 유동시험을 각각 수행하였다. 또한, 유동해석을 병행하여 제트베인간의 유동 간섭 특성을 분석하였다. 연구 결과 제트베인간의 상호간섭은 나타나지 않으며, 제트베인의 공기역학적 특성은 현과 리드의 길이 비에 크게 좌우되고, 최대 추력손실은 롤 제어시 축추력의 17%로 나타났다.

• Journal of Biosystems Engineering
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• 제24권3호
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• pp.209-216
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• 1999

A self-travelling sprayer was developed to avoid the exposure of an operator to agricultural chemicals and exhaust gas, to improve safety and to increase working efficiency during the application and transport work in the greenhouses. This system consists of self-travelling system and the control system for application and safety device. The auto-spray car is equipped with a liquid chemical tank of 80l capacity. The travelling system adopted mechanical steering system which link mechanism of front wheel is guided by guide rollers. The sprayer travels along the guiding pipe which is set on the furrow in the greenhouses. The sprayer stops automatically applying and traveling when the liquid chemical tank becomes empty or when the sprayer reach the turning point. The spray booms swings in a vertical plane. The control system of safety devices controls the automatic stop of the sprayer when there is an obstacle on the traveling path, or when the battery becomes discharged. The auto-spray car traveled smoothly and steadily along the guide pipe during traveling straightly and turning on the ground.

• 한국기계가공학회지
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• 제19권1호
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• pp.100-107
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• 2020

As demand for high value-added products with hard materials increases, the line center is used for producing high value-added products in many industries such as aerospace, automobile fields. The line center is a key device for smart factory automation that can improve the production efficiency and the productivity. Therefore, the development of a mill-turn line center is necessary to produce high value-added products with complex shapes flexibly. In the mill-turn process, a milling process and a turning process are combined. In particular, the turning process needs to increase the rigidity of the spindle. The purpose of this study is to analyze the thermal-structural stability through thermo-structural coupled analysis for a mill-turn spindle with a curvic coupling. The maximum temperature and thermal stability of the spindle were analyzed by thermal distribution. In addition, the thermal deformation and thermal-structural stability of the spindle were analyzed through thermo-structural coupled analysis.

• 대한조선학회논문집
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• 제58권6호
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• pp.415-423
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• 2021

There have been many experimental studies on the manoeuvrability of KRISO Container Ship (KCS). However, the scale ratio of the model ship and the test procedure for each institute are slightly different, so direct comparison for the data is technically difficult to perform. This paper presents the manoeuvrability of the ship with different scale ratios: 1/65.8, 1/42.0, and 1/31.6 in model scale. KRISO conducted Free Running Model Tests (FRMT): 35° turning circle tests and 20/20(10/10) zigzag manoeuvring tests. The test results indicated that advance and tactical diameter in turning circle tests were similar, and overshoot angles in two zigzag manoeuvring tests increased as the model ship size increased. In addition, a basic concept for the FRMT method with an auxiliary X-thrust device was proposed so that the scale effect could be considered in model ship tests.

• 대한인간공학회지
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• 제33권6호
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• pp.453-463
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• 2014

Objective:The purpose of this study is to identify motion patterns for cellular phone and propose a method to identify motion patterns using a motion capture system. Background: In a smart device, the introduction of tangible interaction that can provide new experience to user plays an important role for improving user's emotional satisfaction. Firstly, user's motion patterns have to be identified to provide an interaction type using user's gesture or motion. Method: In this study, a method to identify motion patterns using a motion capture system and user's motion patterns for using cellular phone was studied. Twenty-two subjects participated in this study. User's motion patterns were identified through motion analysis. Results: Typical motion patterns for shaking, shaking left and right, shaking up and down, and turning for using cellular phone were identified. Velocity and acceleration for each typical motion pattern were identified, too. Conclusion: A motion capture system could be effectively used to identify user's motion patterns for using cellular phone. Application: Typical motion patterns can be used to develop a tangible user interface for handheld device such as smart phone and a method to identify motion patterns using motion analysis can be applied in motion patterns identification of smart device.

• Journal of Biosystems Engineering
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• 제34권6호
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• pp.404-410
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• 2009

This study was carried out to develop a self-propelled type explosive subsoiler for improving the root zone soil conditions in orchard and other forest fields. Prototype was designed to be able to inject air and other soil improving material such as lime into soil at the same time, and thus improve the air permeability and drainage of orchard soils to promote the root growth of tree for high quality fruit production. Soil penetration device of explosive subsoiler is composed of air hammer, penetration rob and air injection nozzle. To support the soil penetration device of explosive subsoiler to penetrate vertically, modified Scott-Russel mechanism was used. Timing control device for simultaneous injection of soil improving material with air was attached to the out side wall of air cylinder and as the cylinder move, the soil improving material was injected into soil at the same time. Turning radius of prototype was 2.2-2.3 m with good mobility in sloped land. It took approximately 1 minute for lime injection system to reach the optimum pressure of 9.9 kg/$cm^2$, average 10-20 seconds were required to rupture soil with the depth of 50 cm and 2-3 seconds were required for explosion, so all in all about 1 minute and 20 seconds were required for one cycle of explosion. Maximum soil rupture depth and diameter were 50 cm and 3-4 m respectively depending on the soil type and soil moisture content. For final design of explosive subsoiler inclination angle of lime hopper was increased from 60 degree to 70 degree and the shape of hopper was changed from rectangular cone to circular cone to solve the clogging problem of lime at out let. Agitating system operated by compressed air was attached to the metering device of the prototype, thus more than 90 cc of lime was discharged per cycle from metering device without clogging problems.