• Title/Summary/Keyword: problem analysis

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Wave Response Analysis for Pontoon-type Pier: Very Large Floating Structure (폰툰형 초대형 부유체식 부두의 파랑응답해석)

  • Lee, Sang-Do;Park, Sung-Hyeon;Kong, Gil-Young
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.1
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    • pp.82-89
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    • 2016
  • In this study, we proposed a pier of pontoon-type, "Very Large Floating Structure" (VLFS), with the length of 500m, breadth of 200 m and height of 2 m in Yeosu domestic port. Since this structure ought to endure wave loads for long periods at sea, it is essential to analyze the wave response characteristics. Direct-method is used to analyze the fluid-structure problem and the coupled motion of equation is used to obtain response results. The structural part is calculated by using finite element method (FEM) and the fluid part is analyzed by using boundary element method (BEM). Dynamic responses caused by the elastic deformation and rigid motion of structure are analyzed by numerical calculation. To investigate response characteristics of the pier in regular waves, several factors such as the wavelength, water depth, wave direction and flexural rigidity of structure are considered. As a result, wave response of pier changed at the point of $L/{\lambda}$ 1.5 and represented the torsional phenomenon according to the various incident waves. And the responses showed increasing tendency as the water depths increase at the incident point in case of $L/{\lambda}=8.0$ and peak point of vertical displacement amplitude moved from side to side as the flexural rigidity of structure changes.

A study on the action mechanism of internal pressures in straight-cone steel cooling tower under two-way coupling between wind and rain

  • Ke, S.T.;Du, L.Y.;Ge, Y.J.;Yang, Q.;Wang, H.;Tamura, Y.
    • Wind and Structures
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    • v.27 no.1
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    • pp.11-27
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    • 2018
  • The straight-cone steel cooling tower is a novel type of structure, which has a distinct aerodynamic distribution on the internal surface of the tower cylinder compared with conventional hyperbolic concrete cooling towers. Especially in the extreme weather conditions of strong wind and heavy rain, heavy rain also has a direct impact on aerodynamic force on the internal surface and changes the turbulence effect of pulsating wind, but existing studies mainly focus on the impact effect brought by wind-driven rain to structure surface. In addition, for the indirect air cooled cooling tower, different additional ventilation rate of shutters produces a considerable interference to air movement inside the tower and also to the action mechanism of loads. To solve the problem, a straight-cone steel cooling towerstanding 189 m high and currently being constructed is taken as the research object in this study. The algorithm for two-way coupling between wind and rain is adopted. Simulation of wind field and raindrops is performed with continuous phase and discrete phase models, respectively, under the general principles of computational fluid dynamics (CFD). Firstly, the rule of influence of 9 combinations of wind sped and rainfall intensity on flow field mechanism, the volume of wind-driven rain, additional action force of raindrops and equivalent internal pressure coefficient of the tower cylinder is analyzed. On this basis, the internal pressures of the cooling tower under the most unfavorable working condition are compared between four ventilation rates of shutters (0%, 15%, 30% and 100%). The results show that the 3D effect of equivalent internal pressure coefficient is the most significant when considering two-way coupling between wind and rain. Additional load imposed by raindrops on the internal surface of the tower accounts for an extremely small proportion of total wind load, the maximum being only 0.245%. This occurs under the combination of 20 m/s wind velocity and 200 mm/h rainfall intensity. Ventilation rate of shutters not only changes the air movement inside the tower, but also affects the accumulated amount and distribution of raindrops on the internal surface.

Male Breast Cancer: 20 Years Experience of a Tertiary Hospital from the Middle Black Sea Region of Turkey

  • Serarslan, Alparslan;Gursel, Bilge;Okumus, Nilgun Ozbek;Meydan, Deniz;Sullu, Yurdanur;Gonullu, Guzin
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6673-6679
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    • 2015
  • Background: Male breast cancer is a rare neoplasm, and its treatments are based on those of female breast cancer. This study aimed to analyze 20 years of male breast cancer clinical characteristics and treatment results from the Middle Black Sea Region of Turkey. Materials and Methods: A retrospective analysis of 16 male breast cancer patients treated in our tertiary hospital between 1994 and 2014 was performed. Epidemiologic data, tumor characteristics, and treatments were recorded and compared with 466 female breast cancer ((premenopausal; n = 230) + (postmenopausal n = 236)) patients. The 5-year disease-free and overall survival rates were calculated. Results: Male breast cancer constituted 0.1% of all malignant neoplasms in both sexes, 0.2% of all malignant neoplasms in males, and 0.7% of all breast cancers. The mean patient age in this study was $59.8{\pm}9.5$ (39-74) years. The mean time between first symptom and diagnosis was $32.4{\pm}5.3$ (3-60) months. Histology revealed infiltrative ductal carcinoma in 81.3% of patients. The most common detected molecular subtype was luminal A, in 12 (75%) patients. Estrogen receptor rate (93.8%) in male breast cancer patients was significantly higher than that in female breast cancer (70.8% in all females, p = 0.003; 68.2% in postmenopausal females, p = 0.002) patients. Most of the tumors (56.3%) were grade 2. Tumor stage was T4 in 50% of males. The majority (56.3%) of the patients were stage III at diagnosis. Surgery, chemotherapy, radiotherapy and endocrine-therapy were applied to 62.5%, 62.5%, 81.2% and 73.3%, respectively. Loco-regional failure did not occur in any of the cases. All recurrences were metastastic. The 5-year disease-free and overall survival rates in male breast cancer patients were 58% and 68%, respectively. Conclusions: Tumors found in male breast cancer patients were similar in size to tumors found in females, but they advanced to T4 stage more rapidly because of the lack of breast parenchymal tissues. The rate of estrogen receptor expression tended to be higher in male breast cancer patients than in female breast cancer patients. Metastasis is the most important problem in initially non-metastatic male breast cancer patients.

Score Based Risk Assessment of Lung Cancer and its Evaluation for Bangladeshi People

  • Mukti, Roushney Fatima;Samadder, Pratul Dipta;Emran, Abdullah Al;Ahmed, Farzana;Imran, Iqbal Bin;Malaker, Anyanna;Yeasmin, Sabina
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.17
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    • pp.7021-7027
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    • 2014
  • Background: The problem of cancer, especially lung cancer, is very acute in Bangladesh. The present study was conducted to evaluate the risk of lung cancer among Bangladeshi people based on hereditary, socio-economic and demographic factors. Materials and Methods: This study was carried out in 208 people (patients-104, controls-104) from January 2012 to September 2013 using a structured questionnaire containing details of lung cancer risk factors including smoking, secondhand smoke, tobacco leaf intake, age, gender, family history, chronic lung diseases, radiotherapy in the chest area, diet, obesity, physical activity, alcohol consumption, occupation, education, and income. Descriptive statistics and testing of hypotheses were used for the analysis using SPSS software (version 20). Results: According to this study, lung cancer was more prevalent in males than females. Smoking was the highest risk factor (OR=9.707; RR=3.924; sensitivity=0.8872 and P<0.0001) followed by previous lung disease (asthma, tuberculosis etc.) (OR=7.095; RR=1.508; sensitivity=0.316 and P<0.0001)) for male patients. Highly cooked food (OR=2.485; RR=1.126; sensitivity=0.418 and P=0.004)) and also genetic inheritance (OR=1.93; RR=1.335; sensitivity=0.163 and P=0.138) demonstrated significant correlation with lung cancer as risk factors after these two and alcohol consumption was not prevalent. On the other hand, for female patients, tobacco leaf intake represented the highest risk (OR=2.00; RR=1.429; sensitivity= 0.667 and P=0.5603) while genetic inheritance and highly cooked food also correlate with lung cancer but not so significantly. Socioeconomic status and education level also play important roles in causing lung cancer. Some 78.5% male and 83.3% of female cancer patients were rural residents, while 58.2% lived at the margin or below the poverty line. Most male (39.8%) and female (50.0%) patients had completed only primary level education, and 27.6% male and 33.3% female patients were illiterate. Smoking was found to be more prevalent among the less educated persons. Conclusions: The results obtained in this study indicate the importance of creating awareness about lung cancer risk factors among Bangladeshi people and making appropriate access to health services for the illiterate, poor, rural people.

A Study on Minimization of Leakage of Important Information in M&A (인수합병(M&A)시 기업 중요정보 유출 최소화 방안 연구)

  • An, Young Baek;Chang, Hang Bae
    • The Journal of Society for e-Business Studies
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    • v.25 no.1
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    • pp.215-228
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    • 2020
  • M&As are continuing to grow globally and are expected to increase in the future. With the fourth industrial revolution and the strengthening of neo-protection trade between countries, technology is cited as the core of national competitiveness, and the trend of M&A's increase, which is aimed at securing technology, is expected to continue. However, the risk of technology leakage, which is difficult to determine clearly illegally in the process of M&A, is still growing, and there is not enough prevention or response to this problem. the purpose of this paper was to divide the M&A process into seven stages and to ensure that important information of the enterprises during M&A between the countries and the domestic companies was not leaked unfairly, and each step analyzed the risk factors and causes of the leakage of important information in the M&A process and presented a risk-specific management plan for minimizing the leakage of important information based on the importance of the risk factors. Companies that pursue M&A in the future will reflect the M&A step-by-step risk and risk management measures derived based on case analysis and expert surveys. I hope to use risk management measures to help minimize unintentional leakage of important corporate information into the outside.

A LSTM Based Method for Photovoltaic Power Prediction in Peak Times Without Future Meteorological Information (미래 기상정보를 사용하지 않는 LSTM 기반의 피크시간 태양광 발전량 예측 기법)

  • Lee, Donghun;Kim, Kwanho
    • The Journal of Society for e-Business Studies
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    • v.24 no.4
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    • pp.119-133
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    • 2019
  • Recently, the importance prediction of photovoltaic power (PV) is considered as an essential function for scheduling adjustments, deciding on storage size, and overall planning for stable operation of PV facility systems. In particular, since most of PV power is generated in peak time, PV power prediction in a peak time is required for the PV system operators that enable to maximize revenue and sustainable electricity quantity. Moreover, Prediction of the PV power output in peak time without meteorological information such as solar radiation, cloudiness, the temperature is considered a challenging problem because it has limitations that the PV power was predicted by using predicted uncertain meteorological information in a wide range of areas in previous studies. Therefore, this paper proposes the LSTM (Long-Short Term Memory) based the PV power prediction model only using the meteorological, seasonal, and the before the obtained PV power before peak time. In this paper, the experiment results based on the proposed model using the real-world data shows the superior performance, which showed a positive impact on improving the PV power in a peak time forecast performance targeted in this study.

Classification of Fire Causes in Warehouses Using the TRIZ Technique and Analysis of Preventive Measures Accordingto 4M (TRIZ기법에 의한 물류창고의 화재원인 및 4M에 따른 예방대책 분석)

  • Han, Sang-Hun;Kong, Ha-Sung
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.3
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    • pp.401-412
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    • 2020
  • This study analyzed the causes of warehouse fires using a creative problem-solving technique called TRIZ. It identified preventive measures by applying 4M. The results are as follows. First, this study examined the inconsistency among the causes of warehouse fires using TRIZ. Second, it analyzed human factors and fire prevention measures in warehouses such as safety standards for managers, and methods for the promotion of safety consciousness among workers, and for the reinforcement of construction technology for sandwich panel workers. Third, it identified the mechanical and facility factors and fire prevention measures in warehouses such as safety facilities, the expanded installation of safety devices, the adoption and development of fire suppression equipment, and the deployment of methods to improve the fire resistance of sandwich panels. Fourth, it presented working and environmental factors and fire prevention measures in warehouses such as the tightening of safety precautions and the supervision of working methods, and setting fire partitions both in loading places and based on performance-based design. Finally, it proposed managerial factors and fire prevention measures in warehouses such as specific targeting for firefighting with low fire hazards, reviewing the material quality regulations of non-combustible or higher for sandwich panels in the specific target of firefighting that cannot apply fire safety standards, installing sprinklers in cold storage, and mandating the installation of automated facilities with retroactive application regardless of the floor area in the warehouse with a sandwich panel structure.

Analysis of Website Services of Support Center for Childcare of Districts (시군구 육아종합지원센터 웹사이트 서비스 현황 분석)

  • Chung, Hoe Wook;Kim, Kyoung Mi
    • Korean Journal of Child Education & Care
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    • v.18 no.2
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    • pp.217-230
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    • 2018
  • The purpose of this study is to investigate the consumer centered on-line services of Support Center for Childcare(SCC) of districts. For this purpose this study analyzed the 69 on-line services in websites of SCC. The materials used to evaluate the website services in this study were revised from Lee(2009)'s, Moon(2005)'s and Lee(2005)'s study. The evaluation categories are composed of information providing services, complaints handling services, online participation services, and usability services. The result of this study are as follows. First, in the aspect of information providing services, introduction to SCC, main business of SCC, and related website ranked high. Second, in the aspect of complaints handling services, complaint service board and complaint process notice ranked high. Third, in the aspect of online participation services, on-line application and reservation ranked high. Fourth, in the aspect of usability services, integrated searching, site map, and personal information protection ranked high. The results of this study showed that websites of SCC of districts tried to various services to communicate the consumers. Also the results of this study revealed the contents and problem of websites of SCC, and implied the more systematic and efficient services of SCC.

Development and Application of Landslide Analysis Technique Using Geological Structure (지질구조자료를 이용한 산사태 취약성 분석 기법 개발 및 적용 연구)

  • 이사로;최위찬;장범수
    • Spatial Information Research
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    • v.10 no.2
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    • pp.247-261
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    • 2002
  • There are much damage of people and property because of heavy rain every year. Especially, there are problem to major facility such as dam, bridge, road, tunnel, and industrial complex in the ground stability. So the counter plan for landslide or ground failure must be necessary In the study, the technique of regional landslide susceptibility assessment near the Ulsan petrochemical complex and Kumgang railway bridge was developed and applied using GIS. For the assessment, the geological structures such as bedding and fault were surveyed and the geological structure, topographic, soil, forest, and land use spatial database were constructed using CIS. Using the spatial database, the factors that influence landslide occurrence, such as slope, aspect, curvature and type of topography, texture, material, drainage and effective thickness of soil, type, age, diameter and density of forest, and land use were calculated or extracted from the spatial database. For application of geological structure, the geological structure line and fault density were calculated. Landslide susceptibility was analyzed using the landslide-occurrence factors by probability method that is summation of landslide occurrence probability values per each factors range or type. The landslide susceptibility map can be used to assess ground stability to protect major facility.

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Development and Implementation of Middle School Science Program for Fostering of Students' Creativity Through Partnerships Between University and Local Schools (창의성 계발을 위한 대학과 중등학교간 과학과 연계 프로그램의 개발 및 시범적용 연구)

  • Choi, Byung-Soon;Kim, Beom-Ki;Kang, Seong-Joo;Shin, Jae-Sup;In, Mi-Young;Shin, Ae-Kyung;Kim, Young-Shin;Jin, Jeong-Mi
    • Journal of the Korean Chemical Society
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    • v.48 no.5
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    • pp.510-518
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    • 2004
  • The purposes of this study were to find out the effectiveness of instructional program developed utilizing various strategies to foster the students creativity in science and to analyze the recognition of the students as well as the science teachers on this program for the improvement of the program. Instructional program was consisted of student's worksheet and teacher guidebook. This program was applied to 93 7th grade students for three months. Result of this study showed that the students in experimental group got higher scores than those in the control group, which implied that creativity of the students could be promoted through specially designed program. Analysis of the change of creativity of the students by science achievement showed that the degree of promotion of creativity was higher as the achievement of the students becomes higher. Recognition on this program of the students and teachers who participated in this project revealed positive in that this program was different from the instructional program they have used and that this program would make the students eager to learn and explore the phenomena they faced. Students and teachers also indicated that shortage of instructional time, too many students in class, passive attitude of the students in class discussion, and so on as the problem they have to solve in running the program.