• Title/Summary/Keyword: model-order reduction

Search Result 1,089, Processing Time 0.031 seconds

Cause Analysis of Ship Rework Problems Based on Process Mining (프로세스 마이닝 기반의 선박 재작업 문제에 대한 원인 분석)

  • 신승훈;전정환
    • 산업혁신연구
    • /
    • v.34 no.4
    • /
    • pp.231-254
    • /
    • 2018
  • The purpose of this study is to analyze and remedy the irregular rework problems in shipbuilding industry. We collected and refined the rework event log of the SAP (ERP) outsourcing company of SPP shipbuilding. The process discovery and analysis were performed by fuzzy mining, pattern analysis and bottle neck analysis among process mining methods. The reworking of SPP shipbuilding was found to cause production rework and design change rework as ship owner 's requirement, design improvement, and field work were also causes of immaturity. In addition, method of case analysis result should be carried out in order to prevent PB(ship painting)-2A(ship owner request)-P1(re-work of production) which is the most common pattern in rework process. First, in the shipbuilding industry, the reworking process model and the analysis of the cause of rework contributed to prevention and minimization of rework, productivity improvement and cost reduction. Second, the process mining methodology is analyzed and the guidelines for future research are presented. Finally, it has a significance in that it contributes to improvement of business ability by systematically showing process model, problems and causes to enterprise managers.

유기성 폐기물 간접부담금의 도입과 바이오가스 생산보조 정책의 일반균형효과 분석

  • Bae, Jeong-Hwan
    • Environmental and Resource Economics Review
    • /
    • v.21 no.1
    • /
    • pp.175-210
    • /
    • 2012
  • As London and post-Koyto protocols presumably affect emission of organic waste in Korea in 2012, appropriate treatment of organic waste becomes very important. Organic wastes are regarded as non-point pollutants. It has been criticized that direct emission charges on the emission of non-point pollutants are not effective due to the high uncertainty in the relationship between pollution sources and pollution levels. This study suggests indirect emission charges on production of livestocks or consumption on foods. Furthermore, it is assumed that revenue from the emission charges will be recycled to support biogas production. Biogas can be fueled to produce energy. In order to evaluate potential economic and environmental impacts of recycling the indirect emission charges on organic wastes, a static CGE model was developed. Simulation results of emission charges on the production of livestock show that livestock, agriculture, and food industry will confront relatively high burden while emission charges on consumption of food will affect more broadly and consumers will suffer more. Production charge on livestock sector will lead to higher reduction in GDP and total expenditure relative to the consumption charge. GHGs reduction effect was higher for the consumption charge relative to the production charge. Synthetically, consumption charge on food sector is more desirable as an alternative charge for the emission of organic wastes.

  • PDF

Reduction of Autochthonous Organics in Masan Bay using a Simple Box Model (마산만의 자생 유기물 저감을 위한 단순 박스모델의 적용)

  • Hong, Sok-Jin;Lee, Won-Chan;Yoon, Sang-Pil;Park, Sung-Eun;Cho, Yoon-Sik;Kwon, Jung-No;Kim, Dong-Myung
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.13 no.2 s.29
    • /
    • pp.111-118
    • /
    • 2007
  • Simple box budgets models are useful tools to understand the phenomena of natural system and to provide an insight into the complex processes including physical, chemical and biological processes occurring in natural system. Budgets of fresh water, salt and nutrients were estimated in order to clarify the characteristics of seasonal material cycle in the Masan Bay. Outflow volume of freshwater into system was approximately $307.4\times10^3\sim1,210\times10^3\;m^3/day$. Inflow masses of DIP and DIN were approximately $410.8\sim795.7\;kg/day$ and $4081.4\sim6525.3\;kg/day$, respectively. DIN is expected to accumulate in the system. The removal of nutrients from bottom sediments will contribute to the reduction of 21.0% of COD concentration in the system.

  • PDF

Toward 6 Degree-of-Freedom Video Coding Technique and Performance Analysis (6 자유도 전방위 몰입형 비디오의 압축 코덱 개발 및 성능 분석)

  • Park, Hyeonsu;Park, Sang-hyo;Kang, Je-Won
    • Journal of Broadcast Engineering
    • /
    • v.24 no.6
    • /
    • pp.1035-1052
    • /
    • 2019
  • Recently, as the demand for immersive videos increases, efficient video processing techniques for omnidirectional immersive video is actively developed by MPEG-I. While the omnidirectional video provides a larger degree of freedom for a free viewpoint, the size of the video increases significantly. Furthermore, in order to compress 6 degree-of-freedom (6 DoF) videos that support motion parallax, it is required to develop a codec to yield better coding efficiency. In this paper, we develop a 6 DoF codec using Versatile Video Coding (VVC) as the next generation video coding standard. To the authors' best knowledge, this is the first VVC-based 6 DoF video codec toward the future ISO/IEC 23090 Part 7 (Metadata for Immersive Media (Video)) MPEG-I standardization. The experiments were conducted on the seven test video sequences specified in Common Test Condition (CTC) in two operation modes of TMIV (Test Model for Immersive Media) software. It is demonstrated that the proposed codec improves coding performance around 33.8% BD-rate reduction in the MIV (Metadata for Immersive Video) mode and 30.2% BD-rate reduction in the MIV view mode as compared to the state-of-the-art TMIV reference software. We also show the performance comparisons using Immersive Video PSNR (IV-PSNR) and Mean Structural Similarity (MSSIM).

A Study on the Stormwater Drainage Method of Overflow Type for the Prevention of Urban Flood due to Abnormal Precipitation (이상강우 발생시 도시침수 방지를 위한 월류형 우수배수방법 연구)

  • Seo, Se Deok;Park, Hyung Keun;Kim, Tae Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.39 no.5
    • /
    • pp.569-577
    • /
    • 2019
  • Urban flooding has been a frequent phenomenon in recent years caused by the increase in maximum stormwater runoff arising from abnormal rainfall due to global warming, urban development, and development of lowlands according to population inflows. In order to respond positively against abnormal precipition in the city, it is necessary to check the GWI (Green Water Infra) effect and effectively utilize the existing stormwater detention tanks and treat stormwater to prevent local flooding. In this study, Overflow Type stormwater drainage methods are evaluated as a method of preventing urban flooding in abnormal precipitation using the Dynamic Wave Analysis SWMM (Storm Water Management Model) provided by the United States Environmental Protection Agency. Comparing and analyzing the Upward Watergate Type and Overflow Type, it was analyzed that the Overflow Type reduces the maximum flood discharge by 61 % and the total flood volume by 56 % in the rainfall of Typhoon Kong-rey. The application of the Overflow Type and the natural-pneumatic drainage method to the rainfall of Typhoon Soulik resulted in a 20 % reduction in maximum flood runoff and a 67 % reduction in total flood quantity. Therefore, as a solution to the abnormal rain fall, it is possible to improve the existing stormwater detection tank and install additional facilities. It is expected to be economically possible to strom drainage under limited conditions.

Comparision of Group and Individual Social Support on Burden and Family Functioning in Families with Asthmatic Children (집단 사회적지지와 개별 사회적지지가 천식아동 가족의 부담감과 가족기능에 미치는 영향)

  • 전화연
    • Journal of Korean Academy of Nursing
    • /
    • v.29 no.2
    • /
    • pp.418-428
    • /
    • 1999
  • The main purpose of this study was to identify the effects of group social support and individual social support on the reduction of burden and improvement in family functioning of families with asthmatic children. The design of this study was a randomized pre-posttest quasi-experimental design to compare the two experimental groups. The theoretical framework for this study was derived from the study of burden in family caregivers by Suh and Oh (1993) based on the main effect model of social support theories. The data were collected from February 12, 1998 to May 29, 1998 at the pediatric out patient department of a university hospital located in Suwon city. The sample consisted of 39 family members who were identified as families with asthmatic children, Eighteen subjects were randomly assigned to the group social support group and 21 were assigned to the individual social support group. Group and individual social support members were seen for 60 to 90 minutes, four times over one to three weeks. The instruments used in this study were the Burden Scale developed by Suh & Oh(1993), the Visual Analogue Scale, and the Family Adaptability Cohesion Evaluation Scale(FACES-III) developed by Olson, Portner, and Lavee(1985). The collected data were analyzed using Mann-Whitney test, x$^2$-test, Wilcoxon sign rank test, t-test, ANOVA (Scheff), Pearson correlation coefficient. multiple regression, and social support process and content analysis. The results are as follow : 1. There was no significant difference before the experimental treatment among the subjects in the group social support group and individual social support group for general characteristics, burden, or family functioning. 2. Hypothesis 1 : “There will be a greater reduction on the burden score of the group social support group compared to the individual social support group” was not statistically significant(U=174.5, p=.683). The burden scores showed a significant decrease after participation in social support as compared to before participation for both groups. However there was a tendency for more reduction in the burden scores for the group social support than for individual social support. 3. Hypothesis 2 : “There will be a greater improvement in the family functioning scores for the group social support group compared to the individual social support group” was not statistically significant(U=153.0. p=.309). There was a tendency toward improvement in the family functioning scores of the group social support as compared to that of the individual social support. 4. According to the length of the treatment period, families with asthmatic children displayed affirmative responses, and the families set up a self-help group of mothers with asthmatic children in order to share their experiences, to get information and to solve their problems. In conclusion, it was found that group social support was the more effective nursing intervention for reducing burden and for improving family functioning of families with asthmatic children.

  • PDF

Associations of Serum Isoflavone, Adiponectin and Insulin Levels with Risk for Epithelial Ovarian Cancer: Results of a Case-control Study

  • Otokozawa, Seiko;Tanaka, Ryoichi;Akasaka, Hiroshi;Ito, Eiki;Asakura, Sumiyo;Ohnishi, Hirofumi;Saito, Shigeyuki;Miura, Tetsuji;Saito, Tsuyoshi;Mori, Mitsuru
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.12
    • /
    • pp.4987-4991
    • /
    • 2015
  • Background: The aim of this study was to examine the association of serum isoflavones, adiponectin, and insulin levels with ovarian cancer risk. Materials and Methods: We gathered cases with histologically confirmed epithelial ovarian cancer at Sapporo Medical University Hospital from October 2010 to September 2012. Potential controls were recruited from female inpatients without any history of cancer or diabetes mellitus in different wards of the same hospital over the same period of time. Serum isoflavones, adiponectin, and insulin levels were measured in order to estimate associations with ovarian cancer risk in a case-control study. Data from 71 cases and 80 controls were analyzed with a logistic regression model adjusting for known risk factors. Results: A significant reduction in ovarian cancer risk was observed for the high tertile of serum daidzein level versus the low ($P_{trend}<0.001$). A significant reduction in ovarian cancer risk was also observed for the high tertile of serum glycitein level versus the low ($P_{trend}=0.005$). Furthermore, a significant reduction in ovarian cancer risk was observed for the high tertile of serum adiponectin level versus the low ($P_{trend}=0.004$). Conversely, serum insulin level showed significantly elevated risk for ovarian cancer with the high tertile versus the low $P_{trend}<0.001$). Conclusions: Decreased serum isoflavones levels, such as those for daidzein and glycitein, decreased serum adiponectin levels, and increased serum insulin levels could be shown to be associated with elevated risk of ovarian cancer.

Flow Resistance of Model Cage Net (모형 우리 그물의 유수저항)

  • KIM Tae-Ho;KIM Dae-An;RYU Cheong-Ro;KIM Jae-O;JEONG Eui-Cheol
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.33 no.6
    • /
    • pp.514-519
    • /
    • 2000
  • In order to develop the method for the calculation of flow resistance acting on cage net, the relation between the velocity reduction factor and $S_n/S$, the ratio of total area of netting projected to the perpendicular to the water flow $S_n$ to wall area of netting S, was derived based on the numerical and experimental analysis of the wake flow through a netting twine simplified by a cylinder and a netting panel. The velocity was reduced in accordance with the velocity reduction factor when the flow passed the netting panel upstream of a cage net. The proposed method for the calculation of fluid force acting on a square cage net was based upon the assumption that it could be divided into four side panels and one bottom panel. It was proved that the force could be calculated by the sum of the drag forces acting on the individual netting panels.

  • PDF

Evaluation of GHG Emission in Local Governments using GEBT Model (GEBT를 활용한 지자체 온실가스 배출량 산정 연구 - 시흥시를 중심으로 -)

  • Choi, Bong Seok;Yun, Seong Gwon;Lee, Dong Eun;Jeon, Eui Chan
    • Journal of Climate Change Research
    • /
    • v.4 no.3
    • /
    • pp.291-303
    • /
    • 2013
  • After establishing national greenhouse gas emission reduction goals, the South Korean government has been pursuing sector- and industry-specific greenhouse gas emission reduction measures; in support of which, metropolitan city / state governing entities, such as Gyeonggi Province, etc., have been in lock steps by establishing and executing climate change measures that are appropriate for the regional characteristics. However, in the case of local governments, difficulties abound due to the fact that the per-unit greenhouse gas emission amounts and the future emission estimates for establishing reduction targets are not clear. In order to establish correct climate change measure policies, the policy directions and the assessment of verified greenhouse gas emission amounts would need to serve as the basis, and along with the national level climate change effect and vulnerability assessment, there's a need to develop methodologies that take into consideration the local characteristics and conditions. To this end, this study calculated the greenhouse gas emission amounts of the City of Siheung, a basic local government in Gyeonggi Province, by using the GEBT (Greenhouse gas Emission Business-as-usual Tool) developed by the National Institute of Environmental Research to facilitate easy calculations of BAU (business-as-usual) emission quantities by local governing entities.

Numerical Simulation on Control of Tsunami by Resonator (II) (for Samcheok port) (공진장치에 의한 지진해일파의 제어에 관한 수치시뮬레이션(II) (삼척항에 대해))

  • Lee, Kwang-Ho;Jeon, Jong-Hyeok;Kim, Do-Sam;Lee, Yun-Du
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.32 no.6
    • /
    • pp.496-505
    • /
    • 2020
  • In the previous research, the effectiveness of resonator was confirmed through the numerical analysis on two cases with the use of existing resonator at the Mukho and Imwon ports located in the eastern coast of South Korea by discussing the reduction rates of 1983 Central East Sea tsunami, and 1993 Hokkaido Southwest off tsunami, respectively. In this study, the reduction rates of tsunami height with three different resonators, Type I, II-1, and II-2, at the Samcheok port were examined respectively through the numerical analysis using COMCOT model under the same condition as the previous study. It was discussed the spatial distribution of maximum height of tsunami, change of water level, and effectiveness of resonator with the presence of new types of resonator, and change of their sizes. As a result, the effectiveness of resonator was verified through the application of new types of resonator reducing about maximum 40% of tsunami height. In order to design the optimal resonator for the variety of site condition, it is necessary to research about the various cases applying different shape, arrangement, and size of resonator as further study.