• 한국경영과학회지
• /
• 제16권2호
• /
• pp.137-137
• /
• 1991

This paper compares and evaluates the performances of the two types of mathematical programming models for solving the machine-part cell formation problem in group technology manufacturing : indirect formulation relying on surrogate measure such as similarity coefficient and direct formulation seeking to minimize the number of exceptional elements. New indirect formulation, called the generalized p-median model. is proposed. Unlike existing p-median formulations, proposed formulation includes the classical cell formation problem in which only one process plan exsits for each part as a special case. The proposed new formulation can also deal with the cell formation problem in which alternative process plans exist for a part. The indirect formulation is compared with a new direct formulation which needs much fewer extra variables and constraints than existing direct formulations. Some significant findings from comparative experiment are discussed.

• 경영과학
• /
• 제16권2호
• /
• pp.137-147
• /
• 1999

This paper compares and evaluates the performances of the two types of mathematical programming models for solving the machine-part cell formation problem in group technology manufacturing : indirect formulation relying on surrogate measure such as similarity coefficient and direct formulation seeking to minimize the number of exceptional elements. New indirect formulation, called the generalized {{{{ { p}_{ } }}-median model. is proposed. Unlike existing {{{{ { p}_{ } }}-median formulations, proposed formulation includes the classical cell formation problem in which only one process plan exsits for each part as a special case. The proposed new formulation can also deal with the cell formation problem in which alternative process plans exist for a part. The indirect formulation is compared with a new direct formulation which needs much fewer extra variables and constraints than existing direct formulations. Some significant findings from comparative experiment are discussed.

• 대한치과기공학회지
• /
• 제12권1호
• /
• pp.95-102
• /
• 1990

The distances from the center line between maxillary right and left central incisors(the dental midline) to the various anatomical landmarks were measured. Fifty five students(thirth four males and twenty one females) who have at least natural teeth including maxillary and mandibular incisors and bicuspids were examined. 1. There was statistically significant difference between the dental midline and the center line of maxillary labial frenum(p<0.05). 2. There was no statistically significant difference between the dental midline and the point of incisive papilla, philtrum line, the center line between two mandibular central incisors, and the median palatine suture line(p>0.05). 3. There was no statistically significant sexual difference among data. 4. The philtrum line showed the highest value of correspondence to the center line between two maxillary central incisors followed by the center point of incisive papilla, the center line of two mandibular central incisors, median plaltine suture line and the center line of maxillary labial frenum at the decreasing rate.

• 산업경영시스템학회지
• /
• 제21권46호
• /
• pp.59-72
• /
• 1998

This study is concerned in manufacturing cell formation with operation sequences. Operation sequences must be reflected for manufacturing cell formation anyway, because the primary aim of cellular manufacturing system is to minimize the inter-cell flows, and inter-cell flows are differed by operation sequences. In this study we propose flow-similarity(FS) of reflecting both inter-machine similarity and direct/indirect flow, and then apply the modified P-median model for grouping machines. We also use machine cell-part handling frequency(CPH) so as to be assigned parts to the machine cells having the most CPH. We confirm this approach through an application example. The performance of this approach(FS-model) is evaluated and compared with P-median model and F-model through computational experiments.

• 산업경영시스템학회지
• /
• 제46권4호
• /
• pp.238-245
• /
• 2023

As technologies have been more quickly developed in this 4th Industry Revolution era, their application to defense industry has been also growing. With these much advanced technologies, we attempt to use Manned-Unmanned Teaming systems in various military operations. In this study, we consider the Location-Routing Problem for reconnaissance surveillance missions of the maritime manned-unmanned surface vehicles. As a solution technique, the two-phase method is presented. In the first location phase, the p-median problem is solved to determine which nodes are used as the seeds for the manned vehicles using Lagrangian relaxation with the subgradient method. In the second routing phase, using the results obtained from the location phase, the Vehicle Routing Problems are solved to determine the search routes of the unmanned vehicles by applying the Location Based Heuristic. For three network data sets, computational experiments are conducted to show the performance of the proposed two-phase method.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권1호
• /
• pp.117-122
• /
• 2014

Background: Breast cancer is the most common malignancy and the second leading cause of cancer-related death among women in the developed countries. Despite advances in screening, improved local therapies and adjuvant systemic treatments, median survival of metastatic breast cancer patients (MBC) is in the range of 2-3 years at most. We aimed to investigate whether the prognostic factors and therapeutic responses of our Turkish patients are similar to those in the literature. Materials and Methods: We reviewed the medical records of MBC patients who had been treated in our institution between 1999-2009 and analyzed their clinicopathological features and survival outcomes retrospectively Results: A hundred and sixty patients were included. Median age was 47 (23-82), median follow up was 24 (2-186) months. At the time of diagnosis 59% of patients were under the age of 50 and 46% were postmenopausal. The majority (37%) had multiple sites of metastases. Forty percent received endocrine therapy and 40% chemotherapy as first line metastatic treatment. Thirty (20%) patients were treated with molecular targeting agents like trastuzumab, lapatinib and sunitinib, frequently combined with a chemotherapy agent. Five-year overall survival (OS) was 32% and median OS was 38 months for the whole group. Five year progression free survival (PFS) was 10% and median PFS was 10 months. Menopausal status, hormone receptor expression and disease free status had a significant impact on overall survival in the multivariate analysis (p 0.018, p 0.018 and p:0.003, respectively). Conclusions: All our patients were treated with the modern oncologic therapies recommended by the international guidelines. From our data, MBC patients live up to 3-4 years, indicating that further improvement beyond that requires development of new treatment modalities. The survival outcomes of our patients were consistent with the data reported in the literature.

• Radiation Oncology Journal
• /
• 제32권3호
• /
• pp.163-169
• /
• 2014

Purpose: To report the results of stereotactic body radiotherapy (SBRT) for unresectable primary or recurrent cholangiocarcinoma. Materials and Methods: From January 2005 through August 2013, 58 patients with unresectable primary (n = 28) or recurrent (n = 30) cholangiocarcinoma treated by SBRT were retrospectively analyzed. The median prescribed dose was 45 Gy in 3 fractions (range, 15 to 60 Gy in 1-5 fractions). Patients were treated by SBRT only (n = 53) or EBRT + SBRT boost (n = 5). The median tumor volume was 40 mL (range, 5 to 1,287 mL). Results: The median follow-up duration was 10 months (range, 1 to 97 months). The 1-year, 2-year overall survival rates, and median survival were 45%, 20%, and 10 months, respectively. The median survival for primary group and recurrent group were 5 and 13 months, respectively. Local control rate at 1-year and 2-year were 85% and 72%, respectively. Disease progression-free survival rates at 1-year and 2-year were 26% and 23%, respectively. In univariate analysis, ECOG performance score (0-1 vs. 2-3), treatment volume (<50 vs. ${\geq}50mL$), and pre-SBRT CEA level (<5 vs. ${\geq}5ng/mL$) were significant in overall survival rate. In multivariate analysis, ECOG score (p = 0.037) and tumor volume (p = 0.030) were statistically significant. In the recurrent tumor group, patients with >12 months interval from surgery to recurrence showed statistically significant higher overall survival rate than those with ${\leq}12$ months (p = 0.026). Six patients (10%) experienced ${\geq}$grade 3 complications. Conclusion: SBRT can be considered as an effective local modality for unresectable primary or recurrent cholangiocarcinoma.

• The Journal of the Acoustical Society of Korea
• /
• 제14권1E호
• /
• pp.14-21
• /
• 1995

본 논문은 SIMD 병렬 처리 컴퓨터에 적합한 병렬 분류 알고리즘을 제시키 위해서, 다음과 같이 수행이 된다. 첫째, 비순서화된 데이타 집합을 p개의 프로세서로 할당시킨후에 순차적 quicksort로 분류한다. 그 다음으로, 분류된 각 프로세서의 중위수값을 구한다음 이 값에 위해서 각 프로세서에 데이타 값을 할당시킨다. 각 프로세서에 할당된 데이타가 정확하게 분배가 되도록 중위수와 중위수 값을 구해서 각 프로세서에 적합한 데이타를 다시 할당 시키게 된다. 이때 각 프로세서가 지닌 데이타의 수는 확률이론을 이 용하였다. 마지막으로, 각 프로세서에 할당된 데이타를 순차적 quicksort로 분류하면 된다. 여기서 분류될 데이타 n가 $n{\geq}p^2$일때 본 알고리즘은 최적이 되게됨을 볼수가 있다. 실제적 구현에 있어서, 64개 프로세서를 이용해서 8백만개의 데이타를 분류할때 PSRS 방법의 speedup은 44.4인 반면에 본 알고리즘은 48.43이 된다. 즉, 다양한 공용과 분산 기억장치 기계에 관해서, 본 알고리즘의 speedup은 거의 절반 이상의 선형시간으로서 성취가 됨을 볼 수가 있다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권9호
• /
• pp.5127-5131
• /
• 2013

Background: 5-fluoro-uracil (FU) is a common agent in postoperative chemoradiation in gastric adenocarcinoma. However, FU is not well tolerated in a significant proportion of patients. Capecitabine (CA) is an orally administered fluoropyrimidine carbamate which is preferentially converted to active 5-FU and is one of the agents used instead of FU in such cases. We compared the toxicity, local and distant control and survival rates with FU or oral CA during the course of concurrent radiotherapy to assess the role of CA used instead of FU. Materials and Methods: We conducted an analysis of survival, disease control and toxicity data in 46 patients treated with postoperative chemoradiation following total or subtotal gastrectomy for gastric adenocarcinoma with either FU or CA between January 2008 and December 2012. Results: Median follow-up was 19 months (range: 3-59), median survival time was 23 ({\pm}6.08) months and 1-3 years overall survival (OS) rates were 64.9-39% for all patients. Compared with the CA regimen, the incidence of treatment interruption was higher with FU (p=0.023), but no significant differences were seen in local control (p=0.510), distant recurrences (p=0.721) and survival rates (p=0.866) among patients. Conclusions: Concurrent CA with radiotherapy seems to be a more tolerable and an equally effective regimen for the postoperative treatment of gastric adenocarcinoma when compared to FU.

• Advances in pediatric surgery
• /
• 제9권1호
• /
• pp.41-44
• /
• 2003

Appendicitis is the most common surgical emergency in childhood. Open appendectomy has been the standard treatment. The minimally invasive techniques have been adopted in children after experiences in various surgical conditions in adults has accumulated. It is debatable whether laparoscopic appendectomy (LA) is superior to open appendectomy (OA) in children. The goal of this study is to review the results of laparoscopy and laparotomy in the nonperforated appendicitis. The records of 22 patients under 15 years of age who were operated upon for nonperforated appendicitis at Asan Medical Center were analyzed between December 2002 and April 2003. Age, type and length of intervention, frequency of analgesic use, complication, length of hospitalization, and cost for each treatment groups (N=11) were compared. Laparoscopy patients were older (13.0 vs. 10.1 years; p > 0.05), and operative time was longer (55.0 vs. 35.0 minutes; p < 0.05). There was no conversion (OA to LA). The median length of hospital stay was significantly shorter in laparoscopy (3.0 vs. 2.0 days; p < 0.05). The median cost for LA was more expensive (W833, 836 vs. W751,398; p < 0.05). Even though there were higher costs and longer operative times with laparoscopic procedures, the shorter hospital stay was an advantage.