• Ocean Systems Engineering
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• 제9권4호
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• pp.391-407
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• 2019

Tracking the location (position) of a surface or underwater marine vehicle is important as part of guidance and navigation. While the Global Positioning System (GPS) works well in an open sea environment but its use is limited whenever testing scaled-down models of such vehicles in the laboratory environment. This paper presents the design, development and implementation of a low energy ultrasonic augmented single beacon-based localization technique suitable for such requirements. The strategy consists of applying Extended Kalman Filter (EKF) to achieve location tracking from basic dynamic distance measurements of the moving model from a fixed beacon, while on-board motion sensor measures heading angle and velocity. Iterative application of the Extended Kalman Filter yields x and y co-ordinate positions of the moving model. Tests performed on a free-running ship model in a wave basin facility of dimension 30 m by 30 m by 3 m water depth validate the proposed model. The test results show quick convergence with an error of few centimeters in the estimated position of the ship model. The proposed technique has application in the real field scenario by replacing the ultrasonic sensor with industrial grade long range acoustic modem. As compared with the existing systems such as LBL, SBL, USBL and others localization techniques, the proposed technique can save deployment cost and also cut the cost on number of acoustic modems involved.

• 정보보호학회논문지
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• 제26권1호
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• pp.169-176
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• 2016

안드로이드 플랫폼은 사용자 친화적으로 설계되어 있다. 하지만 이러한 친화적 설계는 취약점이 쉽게 발생할 수 있고, 일반적인 사용자는 쉽게 탐지가 어렵다는 단점을 가지고 있다. 따라서, 본 논문에서는 안드로이드 어플리케이션 분석을 위한 유명한 오픈 소스 분석 도구를 설명하고, 현재 구글의 권한 그룹에 대한 정책의 위험성을 설명한 후 공격자의 권한 상승에 대한 위험을 완화하기 위한 기법을 제안한다. 또한, 21,064의 악성코드 샘플을 조사하여 제안한 기술이 안전하지 않은 응용 프로그램 업데이트 탐지에 대한 증명을 하였을 뿐 아니라 보안 위협에 대한 인식을 고취시키고자 하였다.

• 대한간호학회지
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• 제28권3호
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• pp.650-661
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• 1998

The purpose of this study was to provide fundamental data for determining contents of Fundamental Nursing Practice and developing desirable bedside nursing techniques for clinical nursing areas. Subjects for this study were 86 nurses who were employees of two university hospitals located in Seoul and a district area. Data were collected by questionnaires. Items of Fundamental Nursing Practice were classified into 72 items according to the result from content analysis of 9 textbooks of Fundamental Nursing. The results are as follows : 1) Items which above 80% of respondents practiced during the school inside practice or clinical nursing practice course were axillary temperature measurement, radial pulse measurement, respiratory rate measurement, application of oral hygiene, hand-washing technique, application of hot and cold bags, intramuscular injection technique, open bed-making, soap enema method, application of nelaton catheterization and oral and nasal suction methods. 2) Above 90% of respondents replied that all items except temperature measurement and bed-making were requisite contents for Fundamental Nursing Practice. Above 10% of respondents replied oral and rectal temperature measurement and bed-making were unnecessary content. 3) Above 90% of respondents replied that operating methods of all items except isolation technique, admission and discharge procedures, and retention enema in the Fundamental Nursing Practice course and clinical situation were consistent. The main reasons that respondents did not apply methods which they learned in the Fundamental Nursing Practice course to the clinical situation were 'insufficient time', 'colleagues were using different methods', 'insufficient supply of instuments' or 'inappropriate appliances'.

• 대한전기학회논문지:전력기술부문A
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• 제51권11호
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• pp.568-576
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• 2002

This paper presents a new algorithm for the enhancement of voltage stability by optimal routing (OR) technique. A new voltage stability index (VSI) for optimal routing is also proposed by using theories of critical transmission path based on voltage phasor approach and equivalent impedance method. Furthermore, the proposed algorithm automatically detect the critical transmission path to critical transmission path to critical load which are faced to voltage collapse due to additional real or reactive loading. We also adopt a improved branch exchange (IBE) algorithm based on a tie branch power (TBP) flow equation to apply the OR technique. The proposed IBE algorithm for the VSI maximizing can effectively search the optimal topological structures of distribution feeders by changing the open/closed states of the sectionalizing and tie switches. The proposed algorithm has been evaluated with the practical IEEE 32, 69 bus test systems and KEPCO 148 bus test system to show favorable performance.

• 한국진공학회지
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• 제18권5호
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• pp.390-393
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• 2009

유기물 기반의 전자 소자에서 소자간의 전기적인 전류 흐름 및 기생저항 등을 차단하기 위하여 표면 에너지를 이용한 새로운 패터닝 기법을 제안하였다. 소수성의 perfluoro-alkyl fluorosilanes을 플라즈마 이온 에칭을 이용하여 선택적으로 친수성으로 변환한 뒤 wettability 현상을 통해 유기 물질을 자동 패터닝 하였다. 또한 이 기법을 이용하여 $V_{oc}$ (open circuit voltage): 482 mV, $J_{sc}$ (short circuit current density): 2.4 mA/$cm^2$, FF (Fill factor): 0.58, $\eta$ (Efficiency): 0.95 % 의 특성을 보이는 bulk-이종접합 유기 태양 전지 소자를 제작하였다.

• 대한후두음성언어의학회지
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• 제31권2호
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• pp.92-95
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• 2020

Tracheal granuloma, the most commonly reported sequela of pediatric tracheotomy. A variety of techniques are available for the management of tracheal granuloma. Potassium-titanyl-phosphate (KTP) laser has been previously established as an acceptable technique for removal of laryngeal surgery, which emits a green light with a wave length of 532 nm, which is well-absorbed by hemoglobin and can coagulate and vaporize tissue. The ability to deliver laser energy through a flexible glass fiber makes the technique convenient for use with a rigid bronchoscope, overcoming problems with intraluminal access encountered with earlier attempts at CO2 laser therapy for this problem. Another advantage of KTP laser is the avoidance of the risks and morbidity associated with an open procedure. We report our surgical technique KTP laser in the management of tracheal granuloma removal into the tracheostomy site. KTP laser is good tool for management of tracheal granuloma with low incidence of complications.

• International Journal of Computer Science & Network Security
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• 제22권10호
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• pp.1-10
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• 2022

Nowadays software defect prediction (SDP) is most active research going on in software engineering. Early detection of defects lowers the cost of the software and also improves reliability. Machine learning techniques are widely used to create SDP models based on programming measures. The majority of defect prediction models in the literature have problems with class imbalance and high dimensionality. In this paper, we proposed Centroid and Nearest Neighbor based Class Imbalance Reduction (CNNCIR) technique that considers dataset distribution characteristics to generate symmetry between defective and non-defective records in imbalanced datasets. The proposed approach is compared with SMOTE (Synthetic Minority Oversampling Technique). The high-dimensionality problem is addressed using Ant Colony Optimization (ACO) technique by choosing relevant features. We used nine different classifiers to analyze six open-source software defect datasets from the PROMISE repository and seven performance measures are used to evaluate them. The results of the proposed CNNCIR method with ACO based feature selection reveals that it outperforms SMOTE in the majority of cases.

• Journal of Chest Surgery
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• 제56권1호
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• pp.56-58
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• 2023

Untreated severe tricuspid regurgitation (TR) is associated with poor outcomes. Functional TR occurs secondary to dilatation of the annulus and tethering of the leaflets. Ring annuloplasty alone can correct most cases, but is insufficient in cases of severe annular dilatation due to severe leaflet tethering. In such cases, a tricuspid edge-to-edge technique may be an option. However, stitching of the leaflet tips alone is likely to result in tearing of the leaflets. Approximation of the durable chordae tendineae is considered helpful for this problem. Herein, we present the case of a 39-year-old man who had undergone open-heart surgery for acute type A aortic dissection 13 months earlier. A right mini-thoracotomy approach with a beating-heart strategy was used, which did not require unnecessary pericardial adhesiolysis and dissection. This technique had the advantage of reducing the operation time and the risk of bleeding. To summarize, we present a case of tricuspid valve repair in a high-risk patient with severe leaflet tethering that was successfully managed using these methods.

• Journal of Digestive Cancer Research
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• 제4권2호
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• pp.113-121
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• 2016

Background: We evaluated technique of hepatic resections using suprahilar-extrafascial dissection of Glissonean pedicle with vascular stapling device for pedicle transection with intent to minimize operative time and blood loss. Methods: We analyzed the clinical records of 326 patients who underwent anatomic liver resection by suprahilar-extrafascial pedicle isolation with vascular stapling division technique. Results: The minor liver resections were associated with significantly shorter surgery duration (105.1±21.1 vs. 225.6±75.6) and transection time (40.1±14.5 vs. 96.3±55.2) than major hepatectomies (p<0.0001 for all). The mean blood loss was 350.8±100.5 mL in minor resection and 485.4±250.2 mL in major resection (p=0.001). The mean blood transfusion requirement was 400.8±109.5 mL for minor resections and 550.9±100.0 mL for major hepatectomy (p=0.072). There was no significant difference in morbidity and mortality between groups (p=0.980; p=0.945). Major as well as minor liver resection were oncology superior with no significant difference in the 5-year overall survival rates. Conclusion: Suprahilar-extrafascial dissection of Glissonean pedicle represents an effective and safe technique of liver resection. Presented approach allows early and easy ischemic delineation of appropriate liver territory to be removed with selective inflow vascular control. It is not time consuming and it is very useful in re-resection, as well as oncological reasonable.

• 대한전자공학회논문지TC
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• 제41권11호
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• pp.17-23
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• 2004

본 논문에서는 전 디지털 모뎀의 기저 대역 전송 신호를 IF 출력 신호로 주파수 변환하는 모듈에서 발생하는 국부발진 누설 신호를 역 위상 기법을 사용하여 제거하고, aperture 개방형 루프 공진기로 구성되는 광대역 필터를 구성하여 낮은 군지연과 높은 대역 제한 특성을 갖는 광대역 IF 인터페이스 모듈을 설계하고 제작하였다. 45 Mbps 및 155 Mbps 전 디지털 모뎀을 위한 광대역 IFIU는 전송 대역과 밀접하여 간섭 신호로 작용하는 국부발진 신호의 누설 신호를 -60 dBc 이하로 억압하였으며, 각각의 전송율에 대한 IFIU의 군 지연은 15 ns와 8 ns의 낮은 특성으로 구현하였다. L-대역 중심 주파수와 150 MHz 대역통과 특성을 갖는 모듈의 이득 평탄도는 2 dB 이내의 특성으로 광대역 위성통신 시스템 전송에 필요한 요구 조건을 만족하였다.