• The Journal of the Korean dental association
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• v.17 no.9 s.124
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• pp.701-708
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• 1979

A series of combined impressions, alginate impressions and rubber base impression made of the lower left quadrant of one subject having a cast gold crown with six reference marks on lower let 1st molar. the combined impressions of hydrocolloid were removed from the mouth at 2.5min, after the insertion of the tray. The alginate impressions were removed from the mouth at 2min, after the insertion of the tray. The rubber base impressions were removed from the mouth at 10min. The effect on the accuracy of the combined impressions, alginate impressions and rubber base impressions was obtained following results by comparing the distances between the reference marks in indirect stone cast with the standard measurements of the cast gold crown prior to cementation. The findings through this study could be summarized as follows; 1. The accuracy of combined impression was superior to that of alginate impression, but it was inferior to that of rubber base impressions. 2. Combined impressions produced a little distortion of the mesio-distal length, alginate impressions produced the largest distortion, ut rubber base impressions produced the least distortion.

• International Journal of Control, Automation, and Systems
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• v.6 no.3
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• pp.424-433
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• 2008

An ownship with towed array sonar (TAS) has limited maneuvers due to its dynamic feature, bearing and frequency measurements of a target which are not detected continuously but are often lost in ocean environment. We propose a pre-processing algorithm for the faded bearing and frequency measurements to solve the BFTMA problem of TAS under limited detection conditions. The proposed pre-processing algorithm to restore the faded bearing and frequency measurements is implemented to perform a BFTMA filter even if the measurements of a target are not continuously detected. The Modified Gain Extended Kalman Filter (MGEKF) method based on the Interacting Multiple Model (IMM) structure is applied for a BFTMA filter algorithm to estimate the target. Simulations for the various conditions were carried out to verify the applicability of the proposed algorithms, and confirmed superior estimation performance compared with the existing Bearings-Only TMA (BOTMA).

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1459-1461
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• 1996

The optical and electrical properties of High Power AlGaAs/AlGaAs Infrared LED with DDH( Double power Double Hetero Junction) structure are investigated. The high power LED is recently studied in order to apply to high speed communication devices. The power out of AlGaAs/AlGaAs with DDH structure is 13.0[mW], the forward voltage is 1.45[V], and the average decrease rate of power out is about 5[%] after aging test. The optical and electrical properties of DDH structure LED are superior than that of SH structured LED. The DDH structured LED is suitable to the high speed communication devices.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.748-757
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• 2015

This experiment was carried out the quality of astringent and dried persimmon according to various cultivars and harvesting time. There were need for proper selecting cultivar of astringent persimmon and knowing proper mature degree of persimmon in order to enhance the quality of dried persimmons. Immature persimmons showed lower moisture content, color value and higher hardness than riped and over-riped persimmons. The total quality of riped and over-riped fruit were superior than un-riped fruit.

• Journal of Korean Neurosurgical Society
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• v.63 no.4
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• pp.532-538
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• 2020

Traumatic arteriovenous fistulas (AVFs) involving the external carotid artery are exceedingly rare in young adults. Since an AVF is the most common life-threatening cause for pulsatile tinnitus (PT), meticulous evaluation and treatment of patients with PT is crucial. Here, we present two traumatic AVF cases treated with coil embolization leading to no residual fistulous connections followed by an immediate and complete resolution of PT. A 20-year-old man developed left ear tinnitus three months after a traumatic brain injury involving the right temporal bone fracture. Cerebral angiography demonstrated an enlarged left middle meningeal artery (MMA) and a fistular point at the posterior branch of the MMA draining to the middle meningeal vein (MMV) and the left pterygoid plexus, suggesting an AVF. Another 18-year-old girl developed left tinnitus, left exophthalmos, and conjunctival injection 6 months after a traffic accident involving no demonstrable abnormal findings in the radiologic exam. Magnetic resonance angiography demonstrated a markedly dilated left MMA draining to the MMV, left cavernous sinus, and left superior ophthalmic vein. In both cases, coil embolization was performed with total obliteration of the fistular point.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.2B no.3
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• pp.125-132
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• 2002

PMSMS (permanent magnet synchronous motors) are widely used in industrial applications and home appliances because of their high torque to inertia ratio, superior power density, and high efficiency. For high performance control, accurate informations about the rotor position is essential. Sensorless algorithms have lately been studied extensively due to the high cost of position sensors and their low reliability in harsh environments. A novel position sensorless speed control for PMSMs uses indirect flux estimation and is presented in this paper. Rotor position and angular velocity are estimated by the proposed indirect flux estimation. Linkage flux and magnetic field flux are calculated by the voltage equations and the measured phase current without any integration. Instead of linkage flux calculation with integral operation, indirect flux and differential magnetic field are used for the estimation of rotor position. A proper rejection technique fur current noise effect in the calculation of differential linkage flux is introduced. The proposed indirect flux detecting method is free from the integral rounding error and linkage flux drift problem, because differential linkage flux can be calculated without any integral operation. Furthermore, electrical parameters of the PMSM can be measured by the proposed TCM (time compression method) for soft starting and precise estimation of rotor position. The position estimator uses accurate electrical parameters that are obtained from the proposed TCM at starting strategy. In the operating region, a proper compensation method fur temperature effect can compensate fir the estimation error from the variation of electrical parameters. The proposed novel position sensorless speed control scheme is verified by the experimental results.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.932-934
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• 1999

In this paper, the new IGBT structures with trap injection are proposed to improve switching characteristics of the conventional SOI LIGBT. The simulations are used in order to investigate the effects of the position, width and concentration of trap injection region using 2D device simulator MEDICI. And, their electrical characteristics are analyze and the optimum design parameters are extracted. As a result of simulation, the turn off time for the proposed LIGBT model A by the trap injection is $0.78{\mu}s$. And, the latch up voltage is 3.4V and forward blocking voltage is 168V which are superior to that of conventional structure. In addition, the proposed model is achieved more efficient in switching time and process effort. Therefore, It is shown that the trap injection is very effective to reduce the turn off time with a little increasing of on-state voltage drop if its design and process parameters are optimized.

• Journal of Korean Orthopaedic Sports Medicine
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• v.2 no.2
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• pp.176-180
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• 2003

We describe in this report the accurate reduction of a transverse displaced glenoid fracture through arthroscopic control . We used the lateral and superior (Neviaser portal) portal of the arthroscopic surgery in the shoulder joint for the U 4.0-mm titanium cannulated cancellous screw fixation. The advantages of this treatment are excellent intra-articular visualiBation, decreased soft tissue dissection ,less blood loss, shortened postoperative recovery and early ROM exercise. There(ore, we report the method of operation and the cases .

• Journal of Chest Surgery
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• v.36 no.1
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• pp.59-62
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• 2003

Mediastinal parathyroid cyst is a very rare disease and is usually found incidentally. Surgical excision is the treatment of choice and recurrence is very rare when complete excision is done. A 71-year-old man was referred to our department because of 6$\times$5cm sized right superior mediastinal mass found incidentally on chest X-ray Surgical excision was performed and pathologic findings were confirmed as mediastinal parathyroid cyst. The patient has been followed up postoperatively without recurrence for 4 months up to now. We report a case of mediastinal parathyroid cyst.

• Journal of Chest Surgery
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• v.29 no.2
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• pp.219-222
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• 1996

A 34-year-old man was admitted to the hospital because of ascites, abdominal fullness. computed tomography and cavography revealed inferior vena cavil occlusion just above the hepatic vein and diagnosed as Budd-Chiari syndrome. conservative medical therapy failed to control the symptoms produced from both portal hypertension and versa caval stasis. Therefore, under extracorporeal circulation with moderate hypothermia and normal cardiac contraction, membranoto y and inferior vena casa venoplasty with Gore-tex (10mm) was performed. Postoperatively, physical examination revealed oral ulceration, subcutaneous thrombophlebitis, folliculitic lesions. uveitis And increased reactivity of the skin to needle punctures. 10 month later, superior vena ciiva obstruction symptom was found. Hehcet's disease was diagnosed.