• Title/Summary/Keyword: hazard function

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Applying Discrete-Time Survival Analysis to Testing the Determinants on the Onset of Adolescents' Violence Behavior (비연속시간 생존분석을 적용한 청소년의 최초 폭력 발생시점에 대한 영향요인 검증)

  • No, Un-Kyung;Hong, Se-Hee
    • Survey Research
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    • v.11 no.3
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    • pp.81-101
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    • 2010
  • The purposes of the present study were to investigate the effects of individual, family, and school factors on the onset of adolescents' violence behaviors. For these goals, we applied discrete-time survival analysis to the Korean Youth Panel Survey. According to the estimated hazard function, the likelihood of onset of adolescents' violence behavior was low during elementary school years and increasing sharply from middle school years. Results showed that gender, self-esteem, aggressiveness, broken home, parental abuse, and the number of delinquent friends were significant determinants of the onset of adolescents' violence behaviors. Findings from this study suggest the need to focus on the significant determinants and consider various prevention programs.

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The research regarding the energy storage device which applies the carbon nanotube (탄소나노튜브를 활용한 에너지 저장 소자에 관한 연구)

  • Kim, Do-Hwan;Kang, Soon-Duk
    • The Journal of Information Technology
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    • v.10 no.2
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    • pp.37-45
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    • 2007
  • The multiple-ability which the structure and the physical properties which the carbon or scull tube are unique show the applicability is superior in the plane indication element which is an indispensability of information communications apparatus, the stubbornness memory element, 2nd change of air and the rough copy dosage [khay] plaque seater, the hydrogen store material and the chemical sensor back and it has the possibility which will pass over the limit which the element of existing has. from the present paper it compared in the steel and only 10 the boat it did and it analyzed against an energy storage space voluntary application and developmental apply the carbon or scull tube trend in order about under researching the effective energy storage element it could be appeared, the technique of the strong carbon nano tube. 1. The hazard which embodies the energy storage element which uses the carbon or scull tube it follows in the function which stands and CNT of the structure which is various is necessary. 2. CNT fabrications of each one must precede possible not only must be each Cabinet conference circumstances quality gain and loss. 3. The structural control of syntheses, length controls, diameter controls and the metal - CNT junction control backs of quality CNT must precede. Applies the hereafter carbon or the scull tube in the various element with the primary preceding base technique for the structural plan technique of the carbon or scull tube to be certainly established, it does, secondarily the various element functional control technique which uses the carbon or scull tube is researched and will do.

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Effects on amplification of strong ground motion due to deep soils

  • Jakka, Ravi S.;Hussain, Md.;Sharma, M.L.
    • Geomechanics and Engineering
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    • v.8 no.5
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    • pp.663-674
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    • 2015
  • Many seismically vulnerable regions in India and worldwide are located on deep soil deposits which extend to several hundred meters of depth. It has been well recognized that the earthquake shaking is altered by geological conditions at the location of building. As seismic waves propagates through uppermost layers of soil and rock, these layers serve as filter and they can increase the duration and amplitude of earthquake motion within narrow frequency bands. The amplification of these waves is largely controlled by mechanical properties of these layers, which are function of their stiffness and damping. Stiffness and damping are further influenced by soil type and thickness. In the current study, an attempt has been made to study the seismic site response of deep soils. Three hypothetical homogeneous soil models (e.g., soft soil, medium soil and hard soil) lying on bedrock are considered. Depth of half space is varied from 30 m to 2,000 m in this study. Controlled synthetic motions are used as input base motion. One dimensional equivalent linear ground response analyses are carried out using a computer package DEEPSOIL. Conventional approach of analysing up to 30 m depth has been found to be inadequate for deep soil sites. PGA values are observed to be higher for deeper soil profiles as compared to shallow soil profiles indicating that deeper soil profiles are more prone to liquefaction and other related seismic hazards under earthquake ground shaking. The study recommends to deal the deeper soil sections more carefully for estimating the amplification factors for seismic hazard assessment at the surface.

A Basic Study on the Accident Prevention Measures of Maritime Pilots during Embarkation and Disembarkation (도선사 승·하선 사고예방 방안에 관한 기초연구)

  • LEE, Jin-Woo;KIM, E-Wan;LEE, Chang-Hee
    • Journal of Fisheries and Marine Sciences Education
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    • v.29 no.1
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    • pp.137-147
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    • 2017
  • An accident during pilotage may cause several problems such as crippling the harbour function, environmental disruption, loss of life. Since the pilot plays an important role in the safe operation of the port, securing their safety is directly connected to the vessel's safety coming into port in Korea. Pilotage service is offered on request without distinction of day and night. And traveling by helicopter and boarding/disembarking using a pilot ladder from and to a pilot boat have a high risk of falling into the sea. So, pilots can fall into the sea while boarding/disembarking from ship which can lead to serious injury by cardiac arrest. A number of pilots have died or severely injured due to fall from the pilot ladder during embarkation and disembarkation up to now. Current safety measures at embarkation and disembarkation required by pilotage act and IMO resolutions could not prevent all the pilot related accidents. Therefore, to prevent pilot accident during boarding/disembarking from ship, it is necessary to include safety training requirement for new pilots under the requirements for licensing of pilotage act. It is also necessary to compel pilots to take necessary personal protective equipment when they use a pilot ladder. In addition, the placement of emergency kit on pilot boats and first-aid training are required in order to deal with emergency situation promptly.

An Evaluation Method for Tornado Missile Strike Probability with Stochastic Correlation

  • Eguchi, Yuzuru;Murakami, Takahiro;Hirakuchi, Hiromaru;Sugimoto, Soichiro;Hattori, Yasuo
    • Nuclear Engineering and Technology
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    • v.49 no.2
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    • pp.395-403
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    • 2017
  • An efficient evaluation method for the probability of a tornado missile strike without using the Monte Carlo method is proposed in this paper. A major part of the proposed probability evaluation is based on numerical results computed using an in-house code, Tornado-borne missile analysis code, which enables us to evaluate the liftoff and flight behaviors of unconstrained objects on the ground driven by a tornado. Using the Tornado-borne missile analysis code, we can obtain a stochastic correlation between local wind speed and flight distance of each object, and this stochastic correlation is used to evaluate the conditional strike probability, $Q_V(r)$, of a missile located at position r, where the local wind speed is V. In contrast, the annual exceedance probability of local wind speed, which can be computed using a tornado hazard analysis code, is used to derive the probability density function, p(V). Then, we finally obtain the annual probability of tornado missile strike on a structure with the convolutional integration of product of $Q_V(r)$ and p(V) over V. The evaluation method is applied to a simple problem to qualitatively confirm the validity, and to quantitatively verify the results for two extreme cases in which an object is located just in the vicinity of or far away from the structure.

Surgical Management of Aortic Root Dilatation with Advanced Aortic Regurgitation: Bentall Operation versus Valve-sparing Procedure

  • Lim, Ju-Yong;Kim, Joon-Bum;Jung, Sung-Ho;Choo, Suk-Jung;Chung, Cheol-Hyun;Lee, Jae-Won
    • Journal of Chest Surgery
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    • v.45 no.3
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    • pp.141-147
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    • 2012
  • Background: Although the aortic valve-sparing procedure has gained popularity in recent years, it still remains challenging in patients with advanced aortic regurgitation (AR). We compared the long-term outcomes of the aortic valve-sparing procedure with the Bentall operation in patients with advanced aortic regurgitation secondary to aortic root dilatation. Materials and Methods: A retrospective review of 120 patients who underwent surgery for aortic root dilatation with moderate to severe AR between January 1999 and June 2009 was performed. Forty-eight patients underwent valve-sparing procedures (valve-sparing group), and 72 patients underwent the Bentall procedure (Bentall group). The two groups' overall survival, valve-related complications, and aortic valve function were compared. Results: The mean follow-up duration was $4.9{\pm}3.1$ years. After adjustment, the valve-sparing group had similar risks of death (hazard ratio [HR], 0.61; p=0.45), and valve related complications (HR, 1.27; p=0.66). However, a significant number of patients developed moderate to severe AR in the valve-sparing group at a mean of $4.4{\pm}2.5$ years of echocardiographic follow-up (p<0.001). Conclusion: Both the Bentall operation and aortic valve-sparing procedure showed comparable long-term clinical results in patients with advanced aortic regurgitation with aortic root dilatation. However, recurrent advanced aortic regurgitation was more frequently observed following valve-sparing procedures.

Design of Safe Autonomous Navigation System for Deployable Bio-inspired Robot (전개형 생체모방로봇을 위한 안전한 자율주행시스템 설계)

  • Choi, Keun Ha;Han, Sang Kwon;Lee, Jinyi;Lee, Jin Woo;Ahn, Jung Do;Kim, Kyung-Soo;Kim, Soohyun
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.4
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    • pp.456-462
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    • 2014
  • In this paper, we present a deployable bio-inspired robot called the Pillbot-light, which utilizes a safe autonomous navigation system. The Pillbot-light is mounted the station robot, and can be operated in a disaster relief operation or military operation. However, the Pilbot-light has a challenge to navigate autonomously because the Pilbot-light cannot be equipped with various sensors. As a result, we propose a new robot system for autonomous navigation that the station robot controls Pillbot-light equipped with vision camera and CPU of high performance. This system detects obstacles based on the edge extraction using vision camera. Also, it cannot only achieve path planning using the hazard cost function, but also localization using the Particle Filter. And this system is verified by simulation and experiment.

Overexpression of Semaphorin4D Indicates Poor Prognosis and Prompts Monocyte Differentiation toward M2 Macrophages in Epithelial Ovarian Cancer

  • Chen, Ying;Zhang, Lei;Lv, Rui;Zhang, Wen-Qi
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5883-5890
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    • 2013
  • Previously, we demonstrated overexpression of semaphorin4D (SEMA4D, CD100) to be closely related to tumor angiogenesis in epithelial ovarian cancers (EOCs). However, the function and expression of SEMA4D in the EOC microenvironment has yet to be clarified in detail. In this study, we confirmed that overexpression of SEMA4D in primary tumors and ascites was related to low differentiation, platinum resistance and a refractory status (P<0.05), while high M2 macrophage count and percentage were evident in EOC patients with advanced FIGO stage and platinum resistance (P<0.05), using immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), and fluorescence-activated cell sorting (FACS), respectively. The data showed correlations of SEMA4D expression and M2 macrophage counts in primary tumors and M2 macrophage percentage in ascites (r=0.281 and 0.355, each P<0.05). In the Cox proportional hazard mode, SEMA4D expression was an independent indicator of overall survival (OS) and progression-free survival (PFS) for EOC patients. Furthermore, higher expression of SEMA4D in ovarian cancer cell lines (SKOV3, A2780, and SW626) and their supernatants were found than that in a human primary cultured ovarian cell and its supernatant by reversed transcript PCR (RT-PCR), Western blotting and ELISA, respectively. Interestingly, peripheral blood monocytes (MOs) tended towards the M2-polarized macrophage phenotype ($CD163^{high}$) in vitro after human recombined soluble SEMA4D protein stimulation. These findings suggest that SEMA4D might possibly serve as a reliable tool for early and accurate prediction of EOC poor prognosis and could playan important role in promoting tumor dissemination and metastasis in the EOC microenvironment. Thus SEMA4D and its role in macrophage polarization in EOC warrants further study.

Elevated Circulating CD19+ Lymphocytes Predict Survival Advantage in Patients with Gastric Cancer

  • Yu, Qi-Ming;Yu, Chuan-Ding;Ling, Zhi-Qiang
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.2219-2224
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    • 2012
  • Background: Circulating lymphocyte subsets reflect the immunological status and might therefore be a prognostic indicator in cancer patients. Our aim was to evaluate the clinical significance of circulating lymphocyte subset in gastric cancer (GC) cases. Methods: A retrospective study on a prevalent cohort of 846 GC patients hospitalized at Hospital from Aug 2006 to Jul 2010 was conducted. We calculated the patient's disease free survival (DFS) after first hospital admission, and hazard ratios (HR) from the Cox proportional hazards model. Results: Our findings indicated a significantly decreased percentage of CD3+, and CD8+ cells, a significantly increased proportion of $CD4^+$, $CD19^+$, $CD44^+$, $CD25^+$, NK cells, and an increased $CD4^+/CD8^+$ ratio in GC patients as compared with healthy controls (all P < 0.05). Alteration of lymphocyte subsets was positively correlated with sex, age, smoking, tumor stage and distant metastasis of GC patients (all P<0.05). Follow-up analysis indicated significantly higher DFS for patients with high circulating $CD19^+$ lymphocytes compared to those with low $CD19^+$ lymphocytes (P=0.037), with $CD19^+$ showing an important cutoff of $7.91{\pm}2.98%$ Conclusion: Circulating lymphocyte subsets in GC patients are significantly changed, and elevated CD19+ cells may predict a favorable survival.

A Study on the Operation and Function Improvement for apparel warehouse Using Fuzzy-AHP (Fuzzy-AHP를 활용한 의류 물류창고 운영개선에 관한 연구)

  • Kwon, Sung-Joon;Cha, Young-Doo;Yeo, Gi-Tae
    • Journal of Digital Convergence
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    • v.15 no.9
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    • pp.23-33
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    • 2017
  • Given the expansion of globalization and international trade, the number of apparel consumers is growing every year, making it difficult to estimate the amount of handling needed from the logistics industry. To determine which management factors are important and which ones require improvement, fuzzy AHP was used. Using this method, the factors were ranked in the final analysis as follows: The first and most important factor was training employees (0.17), while the second was fire hazard management (0.169); the third-highest factor was inbound and outbound goods (0.142), and the fourth was the warehouse management system. Barcode management was ranked fifth. By these results, we were able to analyze the processes of clothing warehouses, noting that although the factors appear independent, they are actually connected while proceeding with full management control. Moreover, because of the special characteristics of garments, employee management is crucial. Due to the vulnerability of these goods to fire hazards, this factor must be well managed.