• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11b
• /
• pp.497-500
• /
• 2001

Due to their better photosensitivity in X-ray, the amorphous selenium based photoreceptor is widely used on the X-ray conversion materials. It was possible to control the charge carrier transport of amorphous selenium by suitably alloying a-Se with other elements(e.g. As, Cl). The charge transport properties of amorphous Selenium is decided on hole which is induced from metal to selenium in metal-selenium junction and which is transferred in a-Se bulk. This phenomenon is resulted of changing electric field owing to increasing of space charge by deep trap of a-Se bulk. In this paper, We dopped the chlorine to compensate deep hole trap and deposited blocking layer using dielectric material to prevent from increasing space charge for injection charge between metal electrode and a-Se layer. We compared space charge and the decreasing of trap density through measuring dark and photo current. 缀Ѐ㘰〻ሀ䝥湥牡氠瑥捨湯汯杹

• Journal of Chest Surgery
• /
• v.18 no.2
• /
• pp.360-370
• /
• 1985

A case of complete interruption of aortic arch with aortopulmonary window, patent ductus arteriosus, and aberrantly originated right subclavian artery from proximal descending aorta, in a four year old boy is reported in detail. This is the only reported case in Korea, who has had a successful one-stage total anatomical correction of this combination of defects. Under deep hypothermia and total circulatory arrest, aortic continuity was established using patent ductus arteriosus and anterior wall of pulmonary artery, which was anastomosed obliquely to anteromedial side of ascending aorta. Aortopulmonary window was closed using Impra patch via pulmonary arteriotomy. Then pulmonary arteriotomy was reconstructed primarily except at the junction of right pulmonary artery and main pulmonary artery, where a small piece of pericardium was used to close the defect to prevent kinking and narrowing of right pulmonary artery. Postoperative cardiac catheterization demonstrated a good reconstruction.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2003.03a
• /
• pp.118-118
• /
• 2003

전력반도체 소자로 사용되는 p$^{-}$-n$^{-}$ 접합 다이오드의 스위칭 속도를 향상시키고 그에 따른 에너지 손실을 감소시키기 위해 전자 조사를 실시하였다. Reverse recovery time이 현저히 감소한 반면, 전자 조사에 의한 누설전류와 on-state 전압 강하와 같은 그 외의 전기적 특성 저하는 무시할 수 있는 정도였다. 그밖에 시료의 deep level transient spectroscpy(DLTS) 분석 결과와 secondary ion mass spectrometry(SIMS) depth profile을 근거로 결함 분포와 전자조사 유도결함의 유형을 논하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.26 no.10
• /
• pp.713-719
• /
• 2013

Power MOSFET operate voltage-driven devices, design to control the large power switching device for power supply, converter, motor control, etc. We have optimal designed planar and trench gate power MOSFET for high breakdown voltage and low on resistance. When we have designed $6,580{\mu}m{\times}5,680{\mu}m$ of chip size and 20 A current, on resistance of trench gate power MOSFET was low than planar gate power MOSFET. The on state voltage of trench gate power MOSFET was improved from 4.35 V to 3.7 V. At the same time, we have designed unified field limit ring for trench gate power MOFET. It is Junction Termination Edge type. As a result, we have obtained chip shrink effect and low on resistance because conventional field limit ring was convert to unify.

• Electronics and Telecommunications Trends
• /
• v.32 no.6
• /
• pp.40-47
• /
• 2017

One of the main technical constraints of a conventional battery is the limited lifetime of electric energy supplied. With self-power generation using an internal radioisotope as an emitter of beta particles, and a PN-junction semiconductor as an absorber of the beta particles, a betavoltaic battery can provide electric energy to electric devices in a semi-permanent manner. Hence, a betavoltaic battery can be adopted as the solution to the power source issue of IoT devices placed in locations that people cannot easily access, such as in the deep sea, a desert, and space, and requiring a long operation time without an electrical charging. This paper covers the current trends in betavoltaic batteries including issues regarding their technology, application, and patents.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.2
• /
• pp.97-101
• /
• 2003

New Pt/Ti and hi/Ti double-metal structures have been investigated for the application of a diffusion barrier between Cu and Si in deep submicron integrated circuits. Pt/Ti and Ni/Ti were deposited using E-beam evaporator at room temperature. The performance of Pt/Ti and Ni/Ti structures as diffusion barrier against Cu diffusion was examined by charge pumping method, gate leakage current, junction leakage current, and SIMS(secondary ion mass spectroscopy). These evaluation indicated that Pt/Ti(200${\AA}$/100${\AA}$) film is a good barrier against Cu diffusion up to 450$^{\circ}C$.

• Journal of Chest Surgery
• /
• v.49 no.1
• /
• pp.63-66
• /
• 2016

Neurogenic tumors are the most prevalent tumors of the mediastinum, and schwannomas are the most common type of neurogenic tumor. Primary neurogenic neoplasm of the esophagus is uncommon and malignant schwannoma of the esophagus is extremely rare. We report a case of a 27-year-old female presenting with dysphagia and palpitations who was found to have a lobulated tumor in the mediastinum that was compressing the esophageal lumen. The tumor was successfully treated surgically without recurrence. The final diagnosis, on histopathological examination of the specimen, was malignant schwannoma.

• Journal of the Korean Vacuum Society
• /
• v.4 no.S2
• /
• pp.90-94
• /
• 1995

Defects introduced by Si, Ge preamorphization and their effects on the dopant diffusion and electrical characteristics. Good crystalline quality are obtained after the annealing of Ge ion double implanted samples. The defect clusters under the a/c interface are expected to extend up to the deep in the Si ion implanted samples. The dislocation loops near the junction absorb the interstitial Si atoms resolving from the defect cluster and result in the prevention of enhanced boron diffusion near the tail region of boron profile and show good reverse current charactristics.

• Journal of Veterinary Science
• /
• v.24 no.3
• /
• pp.45.1-45.6
• /
• 2023

Bovine spastic paresis (BSP) is a neuromuscular disorder characterized by hypertension and stiffness of hindlimb. Two Korean native cattle (Hanwoo) calves developed BSP or BSP-like symptoms, and a tenotomy of superficial tendon of medial head and deep tendon of lateral head of gastrocnemius muscle was performed for treatment. A cast was applied postoperatively to prevent muscle rupture and was removed three weeks later. The prognosis was evaluated at 3 weeks, 6 and 18 months postoperatively. Neither calf showed any other postoperative sequelae. This is the first case study to report the diagnosis, treatment, and prognosis of BSP in Hanwoo.

• Journal of Korean Neurosurgical Society
• /
• v.49 no.4
• /
• pp.248-251
• /
• 2011

Objective : In the field of spinal surgery, a few laboratory results or clinical cases about robotic spinal surgery have been reported. In vivo trials and development of related surgical instruments for spinal surgery are required before its clinical application. We investigated the use of the da $Vinci^{(R)}$ Surgical System in spinal surgery at the craniovertebral junction in a human cadaver to demonstrate the efficacy and pitfalls of robotic surgery. Methods : Dissection of pharyngeal wall to the exposure of C1 and odontoid process was performed with full robotic procedure. Although assistance of another surgeon was necessary for drilling and removal of odontoid process due to the lack of appropriate end-effectors, successful robotic procedures for dural sutures and exposing spinal cord proved its safety and dexterity. Results : Robot-assisted odontoidectomy was successfully performed in a human cadaver using the da $Vinci^{(R)}$ Surgical System with few robotic arm collisions and minimal soft tissue damages. Da $Vinci^{(R)}$ Surgical System manifested more dexterous movement than human hands in the deep and narrow oral cavity. Furthermore, sutures with robotic procedure in the oral cavity demonstrated the advantage over conventional procedure. Conclusion : Presenting cadaveric study proved the probability of robot-assisted transoral approach. However, the development of robotic instruments specific to spinal surgery must first precede its clinical application.