• 대한전자공학회논문지TC
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• 제44권6호
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• pp.64-70
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• 2007

본 논문에서는 five-port 접합을 이용한 RF 수신기를 위한 새로운 동시 DC 오프셋 제거와 I/Q 신호 재생 알고리즘을 제안한다. 제안한 방법에서는 단일주파수 CW 신호를 사용하는데, 제안한 방법이 반송파 위상 오프셋에 상관없이 사용할 수 있도록 한다. 또한 제안한 방법은 추가적인 DC 오프셋 제거 기능이 필요 없고, I/Q 재생 파라미터 추정시간을 크게 줄인다. 제안한 방법에서는 변조방식에 상관이 없는 단일주파수 CW 신호를 사용하므로, five-port 접합을 이용한 RF 수신기가 위상편이변조 (PSK) 뿐 만 아니라, 연속위상변조 (CPM)와 직교주파수다중분할 (OFDM)에도 사용될 수 있다.

• 대한전자공학회논문지TC
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• 제45권1호
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• pp.91-96
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• 2008

본 논문에서는 3중 모드를 형성하는 $2{\times}2$배열 피드혼 안테나용 모노 펄스 피드를 설계 제작하고 복사 특성을 고찰하였다. 단일 피드의 경우 이득은 8.25dB의 값을 가지며,. 변환부에서 공기 중으로 연결되는 부위에 전계면으로 확장되는 구조를 갖게 함으로써 이득은 증가하고 구형 도파관과 공기 중의 반사는 저하시켰다. 급전 피드 port1과 port2는 수직으로 위치하여 개구부 혼의 두께를 얇게 함으로써 격리도는 -25dB이하의 특성을 만족하며 높은 주파수일수록 격리도는 향상됨을 확인하였다. port1과 port3은 수평으로 위치하여 전기장의 분포가 병렬로 연결되기 때문에 전기장의 결합은 적게 일어나지만 자기장의 결합이 나타나기 때문에 port1과 port2와의 격리도 보다는 최저 2dB에서 최대 6dB 향상된다. port1과 port4는 구조적으로 직접 결합은 아주 적은 양만 발생하지만, port2와 port3의 영향으로 -35dB이하가 됨을 확인 할 수 있었다.

• Journal of Chest Surgery
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• 제46권4호
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• pp.299-301
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• 2013

Video-assisted thoracic surgery (VATS) is a minimally invasive technique that has many advantages in postoperative pain and recovery time. Because of its advantages, VATS is one of the surgical techniques widely used in patients with lung cancer. Most surgeons perform VATS for lung cancer with three or more incisions. As the technique of VATS has evolved, single-port VATS for lung cancer has been attempted and its advantages have been reported. We describe our experiences of VATS for lung cancer with a single incision in this report.

• Journal of Chest Surgery
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• 제54권4호
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• pp.314-318
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• 2021

In this paper, I present the technique of subxiphoid single-port video-assisted thoracic surgery (VATS) thymectomy for thoracic surgeons to perform this procedure safely. This procedure is indicated for all anterior mediastinal masses and may be extended to lung cancer. The patient is placed in the lithotomy position, and the operator should be on the midline. Below the xiphoid process, a skin incision is made 4-5 cm horizontally at a single thumb's width down. Under two-lung ventilation, CO₂ is insufflated, maintaining 10 mm Hg. The fat tissue and thymic tissue are all resected from the sternum and pericardium between both phrenic nerves using an articulated grasper and an energy device. After retrieval of the mass with a wrap bag, a Jackson-Pratt drain is inserted instead of a chest tube. One of the advantages of this procedure is less postoperative pain than intercostal VATS. The subxiphoid approach can be used for bilateral pneumothorax, bilateral pulmonary metastasectomy, and simple lobectomy for both upper lobes and the right middle lobe.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권4호
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• pp.1458-1470
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• 2018

In this letter, a new dual-port Multiple-Input Multiple-Output (MIMO) antenna is introduced which has two independent signal feeding ports in a single antenna element to achieve smaller antenna volumes for the 5G mobile applications. The dual-port structure is implemented by adding a cross coupled semi-loop (CCSL) antenna as the secondary radiator to the ground short of inverted-F antenna (IFA). It is found that the port to port isolation is not deteriorated when an IFA and CCSL is combined to form a dual-port structure. The isolation property of the proposed antenna is compared with a polarization diversity based dual-port antenna proposed in the literature [9]. The operating frequency range is 3.3-4.0 GHz which is suitable for places where $4{\times}4$ MIMO systems are supposed to be deployed such as in China, EU, Korea and Japan at the band ${\times}$ (3.3 - 3.8GHz. The measured 6-dB impedance bandwidths of the proposed antennas are larger than 700 MHz with isolation between the feeding ports higher than 18 dB [1-2]. The simulation and measurement results show that the proposed antenna concept is a very promising alternative for 5G mobile applications.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.809-812
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• 2005

In this work, a new method for extracting substrate parameters of RF MOSFETs based on 3-port measurement is presented using device simulation. A T-type substrate resistance network is used. 3-port Y-parameter analyses were performed on the equivalent circuit of RF MOSFETs. All the components in the RF MOSFETs when the device is turned off were extracted directly from the 3-port device simulation data. The small-signal output admittance $Y_{22}$ can be well modeled up to 40 GHz. From the 3-port simulation and modeling results, it was verified that the proposed equivalent circuit and parameter extraction method was more accurate than the single substrate resistance model.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1998년도 추계학술대회논문집:21세기에 대비한 지능형 통합항만관리
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• pp.19-49
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• 1998

I try to introduce three types of designs for automatic container operating system which are designed by Institute of Japan Port Research in 1996. Each types are designedto fit with the situations of Japan Port. 'A'type of these designs adapts Dual Container Crane, AGV, RMG, etc. 'B'type of these designs adapts Dual Container Crane, AGV, OHBC, RTG. And 'C'type of these designs adapts Single Container Crane, AGV, OHBC, etc. Even if three designs are introduced, they have some problems to solve for the future. They are Lashing work, Refeer container problem, check for container and seal in main gate, Establishing EDI NETWORK, etc. I expect that this paper will be a helps to development of our port industry.

• Journal of Power Electronics
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• 제19권5호
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• pp.1278-1288
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• 2019

A DC-DC Non-Isolated Three-Port Cuk-Cuk (NI-TPCC) converter for interfacing renewable energy sources (RESs) such as Fuel Cell (FC) and Photovoltaic (PV) energy with a DC load is presented in this paper. It features single-stage power conversion from both of the input ports to the load port. The proposed NI-TPCC converter is designed based on the classical Cuk converter. The operational modes and power flow are analyzed in the continuous conduction mode (CCM), and the relationships among the port voltages are derived. Continuous currents in all three ports with less ripple enhance the performance of a fuel cell and its operating life. Furthermore, the output inductor is shared with both of the input ports, which reduces the number of active and passive components. The effectiveness of the designed NI-TPCC converter has been validated through simulation and experimental results.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 추계학술대회
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• pp.297-302
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• 2004

본 연구에서는 수직배치형 블록을 가지는 컨테이너 터미널을 대상으로 안벽에서 컨테이너의 양${\cdot}$적하 작업을 담당하는 안벽크레인(Q/C)에 대한 하역생산성을 비교분석하였다. 분석 대상이 되는 안벽크레인의 유형은 기존의 싱글트롤리 타입외에 차세대 안벽크레인으로 인식되고 있는 듀얼트롤리, 더블트롤리, 수직순환식의 하역방식을 가지는 장비에 대한 하역생산성을 순작업시간당 생산성 측면에서 이들 하역장비의 성능을 측정해 보았다. 이들 차세대 컨테이너 크레인은 기존의 싱글트롤리 타입의 장비에 비해 기계적 싸이클 타임이 짧으며, 선회방식이 상이하여 현재의 싱글 트롤리타입보다 하역생산성이 매우 높을 것으로 보고 있다. 본 연구의 결과로 제시된 4가지 유형의 안벽크레인에 대해 작업싸이클타임과 시뮬레이션 기법을 이용하여 기계적생산성과 순작업생산성을 산출하였다.

• Clinical and Experimental Reproductive Medicine
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• 제43권1호
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• pp.44-50
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• 2016

Objective: This study was performed to assess our clinical experience with single-port access (SPA) laparoscopic cystectomy and myomectomy and the surgical outcomes of those procedures at our institution. Methods: The authors evaluated the surgical outcomes of SPA laparoscopic cystectomy in 293 patients and SPA laparoscopic myomectomy in 246 patients. The surgical outcomes comprised operation time, the amount of blood loss during the operation, the change in hemoglobin (before and after the operation), the change in hematocrit (before and after the operation), switching to the multi-port access method, complications, transfusions, and the duration of the postoperative hospital stay. Results: The Pearson correlation coefficient and the Spearman correlation coefficient between the operation time and the amount of blood loss were 0.312 and 0.321 for SPA laparoscopic cystectomy, respectively, and 0.706 and 0.674 for SPA laparoscopic myomectomy, respectively. The drops in hemoglobin and hematocrit were $1.33{\pm}0.78g/dL$ and $4.14%{\pm}2.45%$, respectively, in SPA laparoscopic cystectomy, while the corresponding figures were $1.34{\pm}1.13g/dL$ and $4.17%{\pm}3.24%$ in SPA laparoscopic myomectomy, respectively. Conclusion: This study reported the surgical outcomes of SPA laparoscopic cystectomy and myomectomy and compared them to previously published findings on traditional laparoscopic cystectomy and myomectomy. No significant differences were found in the surgical outcomes between SPA and traditional laparoscopic cystectomy and myomectomy.