• Journal of Gastric Cancer
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• v.6 no.3
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• pp.167-172
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• 2006

Purpose: The laparoscopy assisted gastrectomy has been increasingly reported as the treatment of choice for early gastric cancer. However, expert surgeons, who have performed a conventional open gastrectomy for a long time, tend to have a negative attitude toward laparoscopic procedures. The aim of this study was to determine the learning curve of a laparoscopy assisted distal gastrectomy (LADG) for a surgeon expert in performing an open gastrectomy and to analyze the factors that have an effect on a LADG. Materials and Methods: Between April 2005 and March 2006, 62 patients underwent a LADG with D1+beta lymph-node dissection. The 62 patients were divided into 10 sequential groups with 6 cases in each group (the last group was 8 cases), and the time required to reach the plateau of the learning curve was determined by examining the average operative times of these 10 groups. Other factors, such as sex, BMI, complications, transfusion requirements, the number of retrieved lymph nodes, and change of postoperative hemoglobin level, were also analyzed. Results: With the $5^{th}$ group (after 30 cases), the operative time reached a plateau (average: 170 min/operation). The differences between before the $30^{th}$ case and after the $31^{st}$ case with respect to changes in the postoperative hemoglobin level, the number of retrieved lymph nodes, the transfusion requirements, and the complications rate were not significant. Conclusion: According to an analysis of the operative time, experience with 30 LADGs in patients with early gastric cancer is the point at which the plateau of the learning curve (7 months) is reached. Abundant experience with a conventional open gastrectomy and a well-organized laparoscopic surgery team are important factors in overcoming the learning curie earlier.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.11
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• pp.62-72
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• 2003

This paper deals with a crosstalk minimization method by wire spacing. The suggested method uses linear programming method and consider crosstalk of both horizontal segments and vertical segments. In this paper, we suggest a method which can predict the coupling length between vertical segments in the final routing result using longest path algorithm. By the suggested method, we can make LP problem without integer variable. Therefore, it is much faster to solve the problem. In the case of crosstalk optimization, the suggested method optimized peak crosstalk 11.2%, and 3% total crosstalk more than wire perturbation method. The execution time of the suggested method is as fast as it takes 11 seconds when Deutsch is optimized.

• Investigative Magnetic Resonance Imaging
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• v.17 no.1
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• pp.26-32
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• 2013

Purpose : This study was performed to evaluate the presence and severity of Hill-Sachs (HS) lesions on MR arthrography (MRA) of shoulder in patients with Bankart lesions following anterior dislocation and to investigate their relationship with Bankart lesions and frequency of dislocations. Materials and Methods: 86 MRA of shoulder were evaluated in patients with arthroscopic Bankart repairs following anterior dislocations. The largest surface length of HS lesion on MRA and extent of Bankart lesions on arthroscopy were measured. Relationships between length of HS lesions and extent of Bankart lesions and frequency of dislocations were assessed. Results: HS lesions were identified on MRA in 78 patients. The largest surface length of HS lesion ranged from 9.3 mm to 29.6 mm (mean, 18.8 mm). The extent of Bankart lesion ranged from one to six o'clock extent (mean, 4.25 o'clock extent). Three patients had single dislocation and the other 75 patients had recurrent dislocations (mean 24.5 times). The largest surface length of HS lesions was positively correlated with extent of Bankart lesions (p = 0.001, r = 0.37), but not with frequency of dislocation. Conclusion: HS lesion was very common in patients with Bankart lesion. The severity of HS lesions was correlated with extent of Bankart lesions.

• Clinics in Shoulder and Elbow
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• v.16 no.1
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• pp.10-16
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• 2013

Purpose: To know if magnetic resonance image (MRI) re-examination is needed before surgery, we compared the pre-operative MRI recorded at different time points and the corresponding arthroscopic findings. Materials and Methods: Depending on the timing of evaluation, the MRI was classified into three groups: group A, MRI was taken 1 month before the surgery (44 cases, average 16 days); group B, 1-6 months before the surgery (41 cases, average 91 days); and group C, 6-12 months before the surgery (25 cases, average 230 days). The anterior to posterior tear size (length) and medial retraction size (width) of rotator cuff tear were measured for each group and they were compared with the actual arthroscopic findings. Results: Results of this study showed that arthroscopic rotator cuff tear length and width were larger than those of MRI. The difference of the rotator cuff tear size was 3.6(${\pm}1.2$) mm of length and 0.6(${\pm}0.4$) mm of width in group A, 4.2(${\pm}1.7$) mm and 2.4(${\pm}1.1$) mm in group B, and 4.5(${\pm}2.1$) mm and 3.0(${\pm}1.5$) mm in group C. There was a tendency of the larger size difference for longer pre-operative period, but it was not statistically significant. Conclusion: The rotator cuff tear size did not show remarkable differences between pre-operative MRI taken within 1 year before surgery and the actual arthroscopy. It is concluded that additional MRI evaluation is not required within 1 year.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.9A
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• pp.1475-1484
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• 2001

본 논문에서는 최근 이슈가 되고 있는 Mobile-IPv6에서의 새로운 smooth 핸드오프기반의 이동 멀티캐스트 데이터그램 전달 기법을 제안하고 이에 대한 성능을 평가한다. 제안된 알고리즘은 긴 라우팅 경로가 문제였던 Mobile-IPv4에서의 문제를 해결한 Mobile-IPv6를 기초로 하며, Mobile-IPv6 적용시 멀티캐스트 데이터그램 서비스를 운용하는데 요구되는 여러 성능 척도하에서 성능을 평가한다. 새로운 프로토콜의 핵심요소는 멀티캐스트 데이터그램 전달 경로를 줄이기 위해 MDA (Multicast Delivery Agent)를 도입한 것이다. 제안된 프로토콜은 현재까지 제안된 이동망에서의 멀티캐스트 지원 기법 등과 비교하여, 짧은 라우팅 경로 및 이동 호스트에 근접한 노드에서 이동 호스트로의 직접 데이터그램 전송을 통하여 성능 향상을 기대할 수 있다. 특히, 터널링 수 및 멀티캐스트 데이트그램의 평균 라우팅 길이가 줄었으며, 또한 멀티캐스트 트래픽 부하도 감소하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.137-137
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• 2019

돌출줄눈은 산지하천의 만곡부의 빠른 유속을 감소시키기 위하여 활용된다. 본 연구에서는 친환경 디자인의 나무줄기 돌출줄눈(Tree Trunk Rip, TTR)과 사다리꼴 돌출줄눈(Trapezoid Rip, TR)의 흐름저항을 비교 분석하기 위하여 개수로 수리실험을 수행하였다. 실험은 길이 9m, 폭이 0.6m이며 경사가 0.0035로 고정된 개수로의 한쪽 측벽에 돌출줄눈을 설치하여 진행하였다. 사다리 꼴 돌출줄눈의 형상은 밑변 각이 $63^{\circ}$이며 무차원 설치간격 ${\lambda}_{nv}$가 6, 9, 12인 경우이다. 나무줄기 돌출줄눈의 기본 형상은 사다리꼴이고 표면은 나무껍질 무늬이며 ${\lambda}_{nv}$가 약 10이다. 나무줄기 돌출줄눈의 간격은 사다리꼴 돌출줄눈의 최적 설치 간격 9~12배 범위에 해당되고 평균 마찰계수는 사다리꼴 돌출줄눈의 9~12배의 평균 마찰계수 범위에 포함되었다. 사다리꼴 돌출줄눈의 ${\lambda}_{nv}$가 9, 12일 때의 전체 저항에 대한 형상저항의 비는 평균 $69.4{\pm}5.8%$였으며 나무줄기 돌출줄눈은 $70.2{\pm}2.1%$로 사다리꼴 돌출줄눈과 유사하다. 산지하천 흐름저항을 위한 돌출줄눈 설치에 있어 친환경적 디자인을 고려한 나무줄기가 사다리꼴 돌출줄눈보다 활용도가 클 것으로 기대된다.

• The Journal of the Acoustical Society of Korea
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• v.41 no.3
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• pp.319-325
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• 2022

The variation of utterance lengths is a representative factor that can degrade the performance of speaker verification systems. To handle this issue, previous studies had attempted to extract speaker features from various branches or to use convolution layers with different receptive fields. Combining the advantages of the previous two approaches for variable-length input, this paper proposes integrated receptive field diversification that extracts speaker features through more diverse receptive field. The proposed method processes the input features by convolutional layers with different receptive fields at multiple time-axis branches, and extracts speaker embedding by dynamically aggregating the processed features according to the lengths of input utterances. The deep neural networks in this study were trained on the VoxCeleb2 dataset and tested on the VoxCeleb1 evaluation dataset that divided into 1 s, 2 s, 5 s, and full-length. Experimental results demonstrated that the proposed method reduces the equal error rate by 19.7 % compared to the baseline.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.446-451
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• 2017

The length frequency and weight-length relationships within the loach population of Misgurnus anguillicaudatus were investigated in environment-friendly (EFP) and conventional paddy fields (CP) in South Korea, in order to identify the influences of farming practices to the loach population living in paddy ecosystem. The size-frequency of distribution of M. anguillicaudatus populations noted to differ significantly when the loach populations of the EFP and the CP were compared. The mean weight and length of the loach population in EFP was greater than those of the loaches in CP. The equations based on weight and total length relationship in EFP and CP were $W=0.000004L^{3.0747}$ and $W=0.000002L^{3.2106}$, respectively. The condition factor (K) against total length of loaches at two paddy field types with different farming practices indicates that the loach population in EFP(mean K=0.95) had access to better nutritional conditions than those in CP (mean K=0.67). It therefore appears that the size and structure of loach populations in rice paddy fields might be affected by farming practices.

• Journal of the Korea Society of Computer and Information
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• v.14 no.1
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• pp.9-15
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• 2009

Ant Colony System is new meta heuristic for hard combinatorial optimization problem. The original ant colony system accomplishes a pheromone updating about only the global optimal path using global updating rule. But, If the global optimal path is not searched until the end condition is satisfied, only pheromone evaporation happens to no matter how a lot of iteration accomplishment. In this paper, the length of the global optimal path does not improved within the limited iterations, we evaluates this state that fall into the local optimum and selects the next node using changed parameters in the state transition rule. This method has effectiveness of the search for a path through diversifications is enhanced by decreasing the value of parameter of the state transition rules for the select of next node, and escape from the local optima is possible. Finally, the performance of Best and Average_Best of proposed algorithm outperforms original ACS.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.1
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• pp.30-36
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• 1991

Various nerves from many areas of body can be used as a donor of autogenous nerve graft in the microneurosurgical repair of the oral and maxillofacial region. In the grafting procedure of nerve repair, the best results will be achieved with a maximum approximation of fascicular surface at both the porximal and the distal stumps. Therefore, appropriate selection of donor nerve will bring out the best results. The sural nerve has been used as one of the most popular donor nerve in the microneurosurgical repair of the oral and maxillofacial region. The authors examined the fascicular characteristics of the human sural nerve microscopically and compare this results with our previous report of the greater auricular nerve and that of the inferior alveolar nerve.