• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1132-1135
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• 1996

The objective of this paper is to make a model-based map for the localization of an autonomous mobile robot(AMR) from ultrasonic sensor measurements, that are acquired when the AMR explores unknown indoors. First, the AMR navigates on unknown space by wall-following and gathers range data from the ultrasonic sensor. Then, the range data are converted to a wall-marked gird map, from which lines representing the walls are extracted using the Hough transform. This process is implemented on an AMR having an ultrasonic sensor, and a preliminary experimental result is presented.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.11a
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• pp.169-173
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• 1998

The practice of the construction and management of the underground petroleum storage facilities in Korea was investigated extensively, and the problems were identified. The advanced technologies in the U.S.A was comparatively studied. Considering the effectiveness of leak prevention and technology applicability, the following measures were suggested. To prevent corrosion of the tank, a clad tank, an interior-lining tank, or a double-wall tank was appropriate and appeared to be most cost effective. For piping, non-metalic material was suggested. To prevent spill, a catchment basin can be effective. For monitoring of leak, construction of more than one of one or combination of an automatic leak-detection device, a vapor-detection system, a ground water-monitoring system, and a double-wall detection system was recommended.

• Journal of Chest Surgery
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• v.28 no.6
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• pp.623-629
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• 1995

Rupture of ventricular septum following myocardial infaction is one of the serious complication of coronary artery disease. The characteristic manifestations are sudden appearance of a harsh systolic murmur, precordial pain, cardiovascular collapse and permit early diagnosis. We report two cases of successful repair of postinfaction ventricular septal defect. The infarcted area was anterior wall of ventricle and VSD was placed near apex of heart in two cases all. VSD was closed with pledgetted Dacron patch and incised wall was sutured with Teflon felt and concomitant coronary artery bypass graft was done respectively .Postoperative courses were uneventful.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.323-326
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• 2006

Numerical solutions for spin-up problem of a thermally stratified fluid in a cylinder with an insulating sidewall and time-dependent rotation rate are presented. Detailed results are given for aspect ratio of O(1), fixed Ekman number $10-^{4}$, Rossby number 0.05 and Prandtl number O(1). Angular velocity of a cylinder wall changes with following formula, $\Omega_f=\Omega_i+\Delta\Omega[1-\exp(-t/t_c)]$. Here, this $t_c$, value, which is very significant in present study, represents that how fast/slow the angular velocity of the cylinder wall reaches final angular velocity. The normalized azimuthal velocity and meridional flow plots for several tc value which cover ranges of the stratification parameter S(1 ~ 10) are presented. The role of viscous-diffusion and Coriolis term in present study is examined by diagnostic analysis of the azimuthal velocity equation.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.2
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• pp.259-264
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• 1993

Rice straw treated with anhydrous ammonia and/or sulphur dioxide was incubated with rumen liquor for 24 hours and 48 hours to investigate the changes in cell wall structure caused by the treatments and bacterial degradation using scanning electron microscopy (SEM). A less significant tissue loss of untreated rice straw was inspected after incubated for 24 hours and 48 hours. Sulphuration decreased the thickness of sclerenchyma and apparently removed parenchyma tissues. Ammoniation degraded the phloem, and the lignified inner portion of the cell wall was completely, however, little collapsed epidemis and vascular bundles. Ammonia and Sulphur dioxide combined treatment removed the inner layer from outer layer. The extent of apparent degradability following combination treatment was the largest due to the enhanced microbial degradation of sclerenchyma and parenchyma cells.

• International Journal of Control, Automation, and Systems
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• v.2 no.2
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• pp.238-246
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• 2004

In displaying a virtual wall using a passive haptic device equipped with passive actuators such as electric brakes, unsmooth motion frequently occurs. This undesirable behavior is attributed to time delay due to slowness in the virtual environment update and force approximation due to the inability of a brake to generate torque in arbitrary directions. In this paper a new control scheme called direct control is proposed to achieve smooth display on the wall-following task with a passive haptic device. In direct control, brakes are controlled so that the normal component of a resultant force at the end-effector vanishes, based on the force analysis at the end-effector of the passive haptic device using the passive FME (Force Manipulability Ellipsoid). Various experiments have been conducted to verify the validity of the direct control scheme with a 2-link passive haptic system.

• Journal of the Korean housing association
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• v.7 no.2
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• pp.57-68
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• 1996

The study is to investiagte the transition of types of Deul-E-Yul-Gae(lift up) windows and doors in Korean traditional architecture which was on the wall batween Dar Chung and Bang. As the result of studying and analysizing the transition of those the following conclusion could be obtained. The first type was to attach windows on the middle of Deul-E-Yul-Gas(lift up) doors, the second type remove windows attached on that or be(Maeng-Jang-Jee) dark paper covered door annexed Bool-Bal-Gee, and the third type to be (Myung-Jang-Jee) bright paper covered door of bottom panel slender ribs which was the most openness. Finally, we could understand the transition which would be changed from the type of(Maeng-Jang-Jee) bright paper covered lift up door of bottom panel slender ribs that had a pliable and open mood.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.8
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• pp.947-953
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• 2007

Occurrence of pressure pulsation in positive displacement hydraulic turbine is one of the principal problems which should be cleared to improve the turbine performance and to put the turbine to practical use. Therefore, present study is tried to examine the occurrence mechanism and characteristics of the pressure pulsation CFD analysis and experimental measurement are implemented in this study to clarify the phenomena of unsteady pressure pulsation. The results show that occurrence reason of the pressure pulsation is not only due to a series of opening and closing of the chamber formed between rotor and casing wall but also due to the variation of rotational speed of following rotor. The pressure pulsation causes torque variation and the curve patterns of the torque variation conforms to that of the pressure pulsation. Pressure in the chamber is equal to the averaged value of inlet and outlet pressures. Sudden pressure decrease by accelerated through-flow between lobe and casing wall results in torque loss.

• Journal of Chest Surgery
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• v.27 no.3
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• pp.230-233
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• 1994

A 21-year-old man with atrioventricular[AV] reentry tachycardia secondary to concealed accessory AV connection underwent surgical division of two accessory pathways following failure of radiofrequency catheter ablation. pathways were located in the left free wall area.Before cardiopulmonary bypass, the epicardial mapping confirmed the existence and localization of two accessory pathways. The patient was approached through a left atriotomy with a dissection of the left free wall area beginning with an internal mapping was carried out after separation from cardiopulmonary bypass to confirm the absence of retrograde conduction of accessory pathway. Five weeks after surgery, the electrophysiololgic study demonstrated no retrograde conduction through two accessory pathways.

• Journal of Chest Surgery
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• v.31 no.1
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• pp.66-68
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• 1998

A 27-year-old male presented with an anterior myocardial infarction following blunt chest trauma sustained in motorcycle accident. On examination, there was no visible wound on the chest wall. Echocardiogram showed dyskinesia over anterior left ventricular wall. Subsequent coronary angiogram demonstrated dissection at the proximal portion of the left anterior descending coronary artery and left ventriculogram showed apical anerysm and thrombus. He was treated by coronary artery bypass graft.