• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.5
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• pp.681-687
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• 2017

This paper presents about an implementation of Video Transmitting and Receiving System(VTRS) for acquiring test data. The VTRS consists of two parts. The first is Transmitter Unit(TU) that is installed on a missile to acquire various kinds of data and transmit the data to the ground through RF signals. The second is Receiver Unit(RU) that receives the transmitted RF signals and reconstruct those to the original data. To gather a high speed data reliably and securely on the ground, the TU is designed by considering data transfer scheme, data compression, modulation method, encryption technic, link budget, and antenna radiation pattern. Further, a placement method of multiple receiving stations is suggested. The VTRS has been tested on a field to check the link margins and maximum receiving distance in a real environment. Finally, the VTRS is applied to a missile flight test and gathered high speed data reliably.

• Journal of Digital Contents Society
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• v.19 no.1
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• pp.43-49
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• 2018

Recently, with the rapid increasing demands for data services on the Internet, the need for large-scale data centers has been increased. However, these data centers consume enormous amounts of energy to run numerous servers and equipment. In this paper, we therefore propose a novel scheme to save energy in multimedia servers by concentrating the load on specific servers according to the current load level of the overall system and turning them off immediately. To this end, the number of server groups in which each video is stored is determined according to its popularity so that video playback requests can be evenly distributed to the entire system. Finally, through extensive simulations, we show that our proposed data placement and power management scheme in multimedia servers significantly reduces energy consumption by decreasing the number of servers whose powers are on when compared with the existing method, while maintaining the service quality.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2001.05a
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• pp.318-324
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• 2001

In this paper we propose the adaptive scheme to place more search points as long as the operation tapability of the motion estimator in the video codec permits. And the proposed algorithm takes advantage of the intuitive fact that the quality of the decoded video is more degraded as the spatial frequency of the corresponding block is increased due to the augmentation of local minima per unit area. Thererore, we propose the scheme to enhance the quality by locating relatively more search points in the block with high frequency components by analyzing the spatial frequencies of the video sequence. As a result, the proposed scheme can adaptively place more search points possibly permitted by the motion estimator and guarantees better quality compared to the TSS and FS.

• Proceedings of the Korea Multimedia Society Conference
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• 1998.04a
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• pp.10-15
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• 1998

주문형 비디오 시스템에서 저장되는 영화들의 다중 액세스를 지원하기 위해 영화들은 비디오 서버의 다수의 디스크에 걸쳐 스트라이프되고, 비디오 서버의 디스크 배열들간의 부하 불균형을 피할 뿐만 아니라 저장 공간과 장치 대역폭을 최대로 이용하기 위하여 영화의 블록들은 디스크 배열에 신중히 배치되어야 한다. 본 논문에서는 영화의 인기도를 고려한 동적 디스크 스트라이핑에 기초하는 그룹교대 라운드로빈이라는 영화 배치 방법을 제안하고, 그것의 성능을 시뮬레이션을 통하여 평가한다.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04b
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• pp.113-115
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• 2000

주문형 비디오 서버와 같은 작업을 하는 멀티미디어 서버에서 검색 요청에 대한 보다 효율적인 서비스는 데이터 배치 기법에 의해 많은 영향을 받는다. 특히 사용자들에게 가장 인기있는 몇몇 비디오 데이터들은 많은 사용자들에 의해 동시에 요청되기도 하지만 짧은 시간 간격을 두고 연속적으로 요청되기도 하므로 인기있는 비디오 데이터일수록 데이터의 서로 다른 많은 부분이 동시에 검색될 수 있도록 효율적으로 배치시키는 것이 필요하다. 본 논문에서는 비디오 데이터의 인기도 즉 요청 정도에 따라 스트라이핑 폭을 동적으로 결정하는 배치 정책을 제안하고 실험읕 통해 기존의 정책과 비교한다.

• Journal of the Korea Society for Simulation
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• v.9 no.2
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• pp.51-61
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• 2000

In recent years, significant advances in computers and communication technologies have made multimedia services feasible. As a result, various queueing models and cost models on architecture and data placement for multimedia server have been proposed. However, most of these models do not evaluate dependability of systems. In the design phase of a system, simulation is an important experimental means for performance and dependability analysis. Fault injection simulation has been used in evaluation of dependability metric. In this paper, we develop fault injection simulation model to analyze dependability of parallel video servers. In addition, we evaluate reliability and MTTF(Mean Time To Failure) of systems by using the simulator.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.4
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• pp.112-120
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• 2012

In this paper, we manufactured the wireless video stream system after we scanned EMI(Electro Magnetic Interference)noise in the system. and then, we analysed the noise frequency in the interface, circuit and PCB(Printed Circuit Board). we suggested EMI noise reduction technique. The applied reduction method is low pass filtering, the internal layer placement for high speed video data line and optimization of the system ground condition. the manufactured system improved about 2 ~ 20[dB] margin for EMI limit 40[dBuV/m] at 30 ~ 230[MHz] and 47[dBuV/m] at 230 ~ 1000[MHz].

• Journal of Chest Surgery
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• v.54 no.4
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• pp.239-245
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• 2021

Video-assisted thoracoscopic surgery (VATS) has been established as the surgical approach of choice for lobectomy in patients with early-stage non-small cell lung cancer (NSCLC). Patients with clinical stage I NSCLC with no lymph node metastasis are considered candidates for VATS lobectomy. To rule out the presence of metastasis to lymph nodes or distant organs, patients should undergo meticulous clinical staging. Assessing patients' functional status is required to ensure that there are no medical contraindications, such as impaired pulmonary function or cardiac comorbidities. Although various combinations of the number, size, and location of ports are available, finding the best method of port placement for each surgeon is fundamental to maximize the efficiency of the surgical procedure. When conducting VATS lobectomy, it is always necessary to comply with the following oncological principles: (1) the vessels and bronchus of the target lobe should be individually divided, (2) systematic lymph node dissection is mandatory, and (3) touching the lymph node itself and rupturing the capsule of the lymph node should be minimized. Most surgeons conduct the procedure in the following sequence: (1) dissection along the hilar structure, (2) fissure division, (3) perivascular and peribronchial dissection, (4) individual division of the vessels and bronchus, (5) specimen retrieval, and (6) mediastinal lymph node dissection. Surgeons should obtain experience in enhancing the exposure of the dissection target and facilitating dissection. This review article provides the basic principles of the surgical techniques and practical maneuvers for performing VATS lobectomy easily, safely, and efficiently.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.10
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• pp.135-141
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• 2013

In this paper, we installed three high brightness red, green, and blue LED in one socket and made one pixel unit. And we also developed the full-color display board module and control unit which can express various images such as text, graphics, video image with the combination of pixel units and a number of modules. LED display driver module have a driver circuit within the combination of the RGB pixel dot on unit area. These modules of the existing form can be high priced because of implementation a fixed resolution in specific space and installation space. To overcome these shortcomings, we developed a LED driver and LED pixel modules free in array at random pitch intervals. Display board module of this paper enabled to display smoothly video image which have many data processing quantity through dragging data speed up 36 frames per second. Also there are an effect which is provided more clear image because of improving the flickering of the existing display board.

• Journal of Gynecologic Oncology
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• v.29 no.6
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• pp.87.1-87.4
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• 2018

Objective: Upper paraaortic lymph node dissection (UPALD) to the infrarenal level is one of the most challenging robotic procedures. Because robotic system has the limitation in robotic arm mobility. This surgical video introduces a novel robotic approach, lower pelvic port placement (LP3), to perform optimally and simultaneously both UPALD and pelvic procedures in gynecologic cancer patients using da Vinci Xi system. Methods: The patient presented with high-grade endometrial cancer. She underwent robotic surgical staging operation. For the setup of the LP3, a line was drown between both anterior superior iliac spines. At 3 cm below this line, another line was drown and four robotic ports were placed on this line. Results: After paraaortic lymph node dissection (PALD) was completed, the boom of robotic system was rotated $180^{\circ}$ to retarget for the pelvic lateral displacement. Robotic ports were placed and docked again. The operation was completed robotically without any complication. Conclusion: The LP3 was feasible for performing simultaneously optimal PALD as well as procedures in pelvic cavity in gynecologic cancer patients. The advantage of LP3 technique is the robotic port placement that affords for multi-quadrant surgery, abdominal and pelvic dissection. The LP3 is facilitated by utilizing advanced technology of Xi system, including the patient clearance function, the rotating boom, and 'port hopping' that allows using every ports for a camera. The LP3 will enable surgeons to extend the surgical indication of robotic surgical system in the gynecologic oncologic field.