• 정보처리학회논문지C
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• 제17C권1호
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• pp.81-88
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• 2010

센서네트워크에서 센서는 배터리에 의해 작동이 되며 배터리의 수명이 다하면 더 이상 동작을 할 수 없다. 센서가 수집한 데이터는 효과적인 경로를 통해 싱크노드로 전달되어야 하며 이를 위한 여러 라우팅 알고리즘이 제안되었다. 하지만, 기존의 알고리즘은 데이터를 전송하는데 있어서 전송범위와 전송방향을 고려하지 않기 때문에 많은 노드들이 데이터 전송에 참여하게 되고 결과적으로 많은 에너지를 소모한다. 본 논문에서는 센서 네트워크에서의 효과적인 데이터 전송을 위해 전송범위와 전송방향을 고려한 라우팅 알고리즘인 TDRP(Transmission range and Direction Routing Protocol)를 제안한다. TDRP는 클러스터 또는 그리드를 생성하지 않고, 싱크노드를 중심으로 사분면을 형성하여 패킷의 전송방향을 결정하는 방법으로 네트워크 오버헤드가 적으며, 패킷의 전송방향에 위치하는 노드들 만이 통신에 참여하므로, 에너지 효율성이 기존의 알고리즘들보다 뛰어 나다.

• Archives of Plastic Surgery
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• 제42권5호
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• pp.596-600
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• 2015

Background The uptake of breast reconstruction is ever increasing with procedures ranging from implant-based reconstructions to complex free tissue transfer. Little emphasis is placed on scarring when counseling patients yet they remain a significant source of morbidity and litigation. The aim of this study was to examine the scarring preferences of men and women in breast oncoplastic and reconstructive surgery. Methods Five hundred men and women were asked to fill out a four-page questionnaire in two large Irish centres. They were asked about their opinions on scarring post breast surgery and were also asked to rank the common scarring patterns in wide local excisions, oncoplastic procedures, breast reconstructions as well as donor sites. Results Fifty-eight percent of those surveyed did not feel scars were important post breast cancer surgery. 61% said that their partners' opinion of scars were important. The most preferred wide local excision scar was the lower lateral quadrant scar whilst the scars from the deep inferior epigastric artery perforator (DIEP) flap were most favoured. The superior gluteal artery perforator flap had the most preferred donor site while surprisingly, the DIEP had the least favourite donor site. Conclusions Scars are often overlooked when planning breast surgery yet the extent and position of the scar needs to be outlined to patients and it should play an important role in selecting a breast reconstruction option. This study highlights the need for further evaluation of patients' opinions regarding scar patterns.

• 에너지공학
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• 제2권1호
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• pp.104-113
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• 1993

전력수요의 지속적인 증가와 부하율이 점차 낮아짐에 따라 전력사용을 합리적이고 경제적으로 운용할 필요가 있다. 이를 위하여는 고속응성과 분산배치가 가능한 전력저장 시스템의 전력계통에의 적용 필요성이 대두되고 있다. 본 논문에서는 이와 같은 배경에서 전력저장 전지시스템의 전력계통에의 적용 가능성을 확인하기 위하여 시뮬레이터 형태의 20 kVA 전력저장 전지시스템의 설계, 제작 및 그 특성시험을 수행한 결과를 기술하였다. 전력저장 전지시스템은 전력을 직류로 저장하는 전지부와 전력을 직 ·교류 변화하고 계통과 연계하는 직·교변환부 그리고 이를 제어하는 제어부로 구성되어 있다. 전지부에서는 전력저장용의 새로운 연축전지 시스템을 설계·제작하였으며, 직·교변환부에서는 양방향 인버터 시스템을 적용하여 전지에의 충전과 방전을 글일 시스템으로 하여 충전기와 인버터 기능을 동시에 수행하도록 하였다. 또한 4상한 운전을 가능하게 하여 무효전력보상 기능도 수행하도록 하였다. 이 시스템은 MW시스템의 시뮬레이터 형태로 제작된 것으로 이 연구로부터 얻은 특성 시험 결과를 바탕으로 MW 시스템의 개념설계가 가능하다. 앞으로 전력저장 전지시스템은 수십 MW 시스템까지 구축될 전망이어서 본 연구는 이를 위한 준비 단계라고 할 수 있다.

• 한국식생활문화학회지
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• 제28권4호
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• pp.371-385
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• 2013

This study aimed to classify attendants of a wine training institute according to loyalty for wine training service program and to deduce the core managing points in a wine training program by IPA (Importance-Performance Analysis). Self-administered questionnaires were collected from 192 trainees and statistical data analysis completed using SPSS ver. 18.0. As a result of clustering analysis based on trainee loyalty from both attitude and behavioral perspectives, four classification groups were identified: a "genuine" loyalty group, a "latent" loyalty group, a "mendacious" loyalty group, and a "low" loyalty group. For the genuine loyalty group, the importance of total service quality was 4.32 on average whereas the performance was measured as 4.22; thus there was little difference between importance to quality and performance. However, for the other three groups, especially the low loyalty group, there were significant wide gaps between importance to quality and performance. According to IPA, different service quality items were posted on the 'Focus here' quadrant (a domain with high service quality importance but low performance) by group, while the other three quadrants had several common items regardless of the group. Finally, the core quality managing points were different depending on the level of trainee loyalty. Therefore, it is necessary to plan and conduct a wine training program that reflects the characteristics and needs of its students, which will lead to a differentiated management strategy according to the level of loyalty.

• Journal of Power Electronics
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• 제17권4호
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• pp.1048-1057
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• 2017

An indirect matrix converter (IMC) is a modern power generation system that enables a direct ac/ac conversion without the need for any bulky and limited lifetime electrolytic capacitor. This system also allows four-quadrant operation, generation of sinusoidal output voltage waveforms with variable frequency and amplitude, and control of input power factor. This study proposes a pulse-width modulation-based sliding-mode controller to achieve unity input-power factor operation of the IMC independently of the active power exchanged with the grid, as well as a fast dynamic response. The designed equivalent control law determines, at each sampling period, the appropriate q-axis component of the modulated input current to be injected into the grid through the LC input filter. An integral term of the error is included in the expression of the sliding surface to increase the accuracy of the control method. A double space vector modulation method is used to synthesize the direction of the space vector of the input currents as required by the sliding-mode controller and the space vectors of the target output voltages. Simulation and experimental results are provided to show the effectiveness and evaluate the performance of the proposed control method.

• Journal of Gastric Cancer
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• 제19권2호
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• pp.165-172
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• 2019

Purpose: The robotic system for surgery was introduced to gastric cancer surgery in the early 2000s to overcome the shortcomings of laparoscopic surgery. The more recently introduced da Vinci $Xi^{(R)}$ system offers benefits allowing four-quadrant access, greater range of motion, and easier docking through an overhead boom rotation with laser targeting. We aimed to identify whether the $Xi^{(R)}$ system provides actual advantages over the $Si^{(R)}$ system in gastrectomy for gastric cancer by comparing the operative outcomes. Materials and Methods: We retrospectively reviewed all patients who underwent robotic gastrectomy as treatment for gastric cancer from March 2016 to March 2017. Patients' demographic data, perioperative information, and operative and pathological outcomes were collected and analyzed. Results: A total of 109 patients were included in the $Xi^{(R)}$ group and 179 in the $Si^{(R)}$ group. Demographic characteristics were similar in both groups. The mean operative time was 229.9 minutes in the $Xi^{(R)}$ group and 223.7 minutes in the $Si^{(R)}$ group. The mean estimated blood loss was 72.7 mL in the $Xi^{(R)}$ group and 62.1 mL in the $Si^{(R)}$ group. No patient in the $Xi^{(R)}$ group was converted to open or laparoscopy, while 3 patients in the $Si^{(R)}$ group were converted, 2 to open surgery and 1 to laparoscopy, this difference was not statistically significant. Bowel function was resumed 3 days after surgery, while soft diet was initiated 4 days after surgery. Conclusions: We found no difference in surgical outcomes after robotic gastrectomy for gastric cancer between the da Vinci $Xi^{(R)}$ and da Vinci $Si^{(R)}$ procedures.

• Journal of Gynecologic Oncology
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• 제29권6호
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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.

• 한국콘텐츠학회논문지
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• 제20권12호
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• pp.287-300
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• 2020

본 연구는 노인복지관이 운영하는 실버 오케스트라 프로그램의 실천적 개선 방향을 도출하기 위하여 운영 속성에 대한 중요도-만족도 분석(IPA)을 수행하였다. 우리나라의 춘천동부노인복지관이 운영하는 '춘천 실버 오케스트라' 프로그램을 대상으로 실버회원 그룹(N=53)과 프로그램 운영자 그룹(N=32)을 조사 대상자로 선정하였다. '지역사회와의 연계', '예산 운영', '프로그램 운영', '인력 운영', '홍보전략', '프로그램 운영환경'을 포함하는 6개의 평가영역으로 구성된 평가지표를 설계하였다. 그리고 평가영역에 대하여 22개의 평가항목을 구성하였다. 본 연구의 결과, 실버회원 그룹에서는 '인력 운영'이 중요도와 만족도에서 가장 높은 우선순위를 가지는 것으로 나타났다. 프로그램 운영자 그룹에서는 '예산 운영'과 '인력 운영'이 중요도와 만족도에서 각각 가장 높은 우선순위를 차지하였다. IPA 매트릭스 분석을 통하여 나타난 연구 결과를 기반으로, 성공적인 프로그램 운영을 위해서는 실버회원 그룹과 프로그램 운영자 그룹의 관점에서 현상유지 및 강화, 집중투자 및 개선, 낮은 우선순위, 그리고 과잉노력 지양으로 영역화된 프로그램 운영 속성에 대해서 서로 차별화된 노력과 관심을 지속적으로 가져야 한다는 시사점을 제공한다.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2720-2727
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• 2022

The Generation IV Lead-cooled fast reactor (LFR) take the liquid lead or lead-bismuth eutectic alloy (LBE) as the coolant of the primary cooling circuit. Combined with the natural characteristics of lead alloy and the design features of LFR, the system is the simplest and the number of equipment is the least, which reflects the inherent safety characteristics of LFR. The nuclear main coolant pump (MCP) is the only power component and the only rotating component in the primary circuit of the reactor, so the various operating characteristics of the MCP are directly related to the safety of the nuclear reactor. In this paper, various working conditions that may occur in the normal rotation (positive rotating) of the MCP and the corresponding internal flow characteristics are analyzed and studied, including the normal pump condition, the positive-flow braking condition and the negative-flow braking condition. Since the corrosiveness of LBE is proportional to the fluid velocity, the distribution of flow velocity in the pump channel will be the focus of this study. It is found that under the normal pump condition and positive-flow braking conditions, the high velocity region of the impeller domain appears at the inlet and outlet of the blade. At the same radius, the pressure surface is lower than the back surface, and with the increase of flow rate, the flow separation phenomenon is obvious, and the turbulent kinetic energy distribution in impeller and diffuser domain shows obvious near-wall property. Under the negative-flow braking condition, there is obvious flow separation in the impeller channel.

• 천문학회보
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• 제45권1호
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• pp.43.2-44
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• 2020

We have carried out high-resolution near-infrared (NIR) spectroscopic observations toward 16 Galactic supernova remnants (SNRs) showing strong H2 emission features. A dozen bright H2 emission lines are clearly detected for individual SNRs, and we have measured their central velocities, line widths, and fluxes. For all SNRs except one (G9.9-0.8), the H2 line ratios are well consistent with that of thermal excitation at T~2000 K and their line widths are broader than ~10 km s-1, indicating that the H2 emission lines are most likely from shock-excited gas and therefore that they are physically associated with the remnants. The kinematic distances to the 15 SNRs are derived from the central velocities of the H2 lines using a Galactic rotation model. We derive for the first time the kinematic distances to four SNRs: G13.5-0.2, G16.0-0.5, G32.1-0.9, G33.2-0.6. Among the rest 11 SNRs, the central velocities of the H2 emission lines for six SNRs are well consistent (±5 km s-1) with those obtained in previous radio observations, while for the other five SNRs (G18.1-0.1, G18.9-1.1, Kes 69, 3C 396, W49B), they are significantly different. We discuss the velocity discrepancies in these five SNRs. In G9.9-0.8, the H2 emission shows non-thermal line ratios and very narrow line width (~4 km s-1), and we discuss its origin.