• Title/Summary/Keyword: Build-up factor

Search Result 167, Processing Time 0.022 seconds

Study on Characteristics of Dose Distribution in Tissue of High Energy Electron Beam for Radiation Therapy (방사선 치료용 고에너지 전자선의 조직 내 선량분포 특성에 관한 연구)

  • Na, Soo-Kyung
    • The Journal of Korean Society for Radiation Therapy
    • /
    • v.14 no.1
    • /
    • pp.175-186
    • /
    • 2002
  • The purpose of this study is directly measure and evaluate about absorbed dose change according to nominal energy and electron cone or medical accelerator on isodose curve, percentage depth dose, contaminated X-ray, inhomogeneous tissue, oblique surface and irradiation on intracavitary that electron beam with high energy distributed in tissue, and it settled standard data of hish energy electron beam treatment, and offer to exactly data for new dote distribution modeling study based on experimental resuls and theory. Electron beam with hish energy of $6{\sim}20$ MeV is used that generated from medical linear accelerator (Clinac 2100C/D, Varian) for the experiment, andwater phantom and Farmer chamber md Markus chamber und for absorbe d dose measurement of electron beam, and standard absorbed dose is calculated by standard measurements of International Atomic Energy Agency(IAEA) TRS 277. Dose analyzer (700i dose distribution analyzer, Wellhofer), film (X-OmatV, Kodak), external cone, intracavitary cone, cork, animal compact bone and air were used for don distribution measurement. As the results of absorbed dose ratio increased while irradiation field was increased, it appeared maximum at some irradiation field size and decreased though irradiation field size was more increased, and it decreased greatly while energy of electron beam was increased, and scattered dose on wall of electron cone was the cause. In percentage depth dose curve of electron beam, Effective depth dose(R80) for nominal energy of 6, 9, 12, 16 and 20 MeV are 1.85, 2.93, 4.07, 5.37 and 6.53 cm respectively, which seems to be one third of electron beam energy (MeV). Contaminated X-ray was generated from interaction between electron beam with high energy and material, and it was about $0.3{\sim}2.3\%$ of maximum dose and increased with increasing energy. Change of depth dose ratio of electron beam was compared with theory by Monte Carlo simulation, and calculation and measured value by Pencil beam model reciprocally, and percentage depth dose and measured value by Pencil beam were agreed almost, however, there were a little lack on build up area and error increased in pendulum and multi treatment since there was no contaminated X-ray part. Percentage depth dose calculated by Monte Carlo simulation appeared to be less from all part except maximum dose area from the curve. The change of percentage depth dose by inhomogeneous tissue, maximum range after penetration the 1 cm bone was moved 1 cm toward to surface then polystyrene phantom. In case of 1 cm and 2 cm cork, it was moved 0.5 cm and 1 cm toward to depth, respectively. In case of air, practical range was extended toward depth without energy loss. Irradiation on intracavitary is using straight and beveled type cones of 2.5, 3.0, 3.5 $cm{\phi}$, and maximum and effective $80\%$ dose depth increases while electron beam energy and size of electron cone increase. In case of contaminated X-ray, as the energy increase, straight type cones were more highly appeared then beveled type. The output factor of intracavitary small field electron cone was $15{\sim}86\%$ of standard external electron cone($15{\times}15cm^2$) and straight type was slightly higher then beveled type.

  • PDF

Effects of Selection Criteria for Eco-Friendly Agricultural Products on Purchase Intention (친환경농산물 선택기준이 구매의도에 미치는 영향 : 소비자 태도와 신뢰의 매개, 조절효과를 중심으로)

  • Kim, Mi-Song;Kim, Dong-Hwan;Lee, Gi-Hwang;Youn, Myoung-Kil
    • Journal of Distribution Science
    • /
    • v.11 no.12
    • /
    • pp.71-81
    • /
    • 2013
  • Purpose - This study investigated the effects of consumers' selection criteria for environment-friendly agricultural products on purchase intention and the effects of consumers' attitudes and the reliability of environment-friendly agricultural products on purchase intention by using the theory of planned behavior. Subjective norms of variables of behavioral intention, attitudes toward behavior and control of the behavior were used to create selection criteria, consumers' attitudes and reliability of environment-friendly agricultural products. The study investigated the effects of consumers' selection criteria, attitudes, and reliability of environment-friendly agricultural products on purchase intention constructing models and hypotheses of mediation and moderation between selection criteria for agricultural products and purchase intention by consumers' attitudes and reliability. Research design, data, and methodology - The findings were as follows: first, consumers' selection criteria for environment-friendly agricultural products had a significantly affirmative influence upon purchase intention. Health was the most important factor of selection criteria convenience was more important than quality and familiarity was next. Consumers' attitudes and trust had a significant influence on purchase intention. Second, testing showed that consumers' attitude and trust partially mediated selection criteria: sub-factors and purchase intention were important in selection criteria. Third, testing showed that consumers' attitude and trust had a significant moderation effect between selection criteria and purchase intention. In the test of the moderation effect between sub-factors of selection criteria and purchase intention, consumers' attitude had a significantly positive influence upon health, convenience, and familiarity, and had no significant influence upon quality and purchase intention. Consumers' trust had no significant influence upon health, convenience, and quality. Results - The study provided several theoretical implications: first, an empirical analysis was undertaken with selection criteria for environmental-friendly agricultural products, consumers' attitude, and trust to investigate subjective norms, attitude toward behavior and control of behavior based on the theory of planned behavior. Second, this study investigated both the mediation effect and moderation effect of consumers' subjective norms on attitudes toward behavior, the mediating effects of perceived behavior control and changes of behavioral intention depending upon size and direction of the variables. This study also provided several practical implications. Conclusions - First, consumption of environment-friendly agricultural products did not increase despite rapid increase of production therefore, promotion of consumption and distribution was needed considering the supply and demand of the products. Second, definite standards for selection criteria were suggested to build up consumers' attitude and trust. Consumers' attitude could be improved by factors including the brand of environment-friendly agricultural products, consistent quality, solving physiological problems caused by adverse effects of environmental problems, supplementary approaches, treatment of adverse effects by eating food, and the development and supply of products in accordance with changes of lifestyle. Finally, consumers' demand for sub-factors of selection criteria could be much higher than health, convenience, and quality of the products. Therefore, a process was needed that could continuously check consumers' needs for the products. Limitations were described at the end of the study.

Prediction Model of Suicidal Ideation in Elderly Men Living Alone Based on Ecological System Theory (생태학적 체계이론에 기반한 남자독거노인의 자살생각 예측모형)

  • Hong, Si Myung
    • Journal of agricultural medicine and community health
    • /
    • v.42 no.2
    • /
    • pp.57-68
    • /
    • 2017
  • Objectives: This study was performed to build the predictive model of suicidal ideation of elderly men living alone. Methods: As for the subject, 251 subjects suitable for the selection criteria were selected among elderly men living alone above 65 years old in one region in Gyeongnam and three regions in Gyeongbuk. The data were collected via questionnaires and analyzed using SPSS version 20.0 and Amos version 18.0. Results: The goodness-of-fit test result of hypothetical model were suitable for recommended level: ${\chi}^2/df=1.47$, RMR=.04, GFI=.92, AGFI=.90, CFI=.95, IFI=.95, RMSEA=.04. Self-esteem, individual coping, family cohesion, social support, social activity, and depression explained 55% of the model of suicidal ideation. The most influential direct factor of suicidal ideation was self-esteem, and social isolation was the most influential indirect influence on suicidal ideation. Conclusion: To sum up the above results, if we promote the researched variables of self-esteem, family cohesion, social activity, individual coping and social support in addition to developing and utilizing an efficient customized suicidal prevention nursing intervention program thereby reducing depression and social isolation, suicidal ideation of elderly men living alone would be prevented.

A Study on the Competitiveness Improvement of Coastal Shipping for Northeast Asia Logistics-Hub (동북아(東北亞) 물류거점화(物流據點化)를 위한 연안해운(沿岸海運) 경쟁력(競爭力) 제고방안(提高方案)에 관(關)한 연구(硏究))

  • Lee, Yon-Jae;Ahn, Ki-Myung;Kim, Kwang-Hee;Kim, Hyun-Duk
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • v.29 no.1
    • /
    • pp.441-449
    • /
    • 2005
  • The purpose of this research is to present the improvement measure of lagging behind coastal shipping system to be a logistic hub-nation with a competitive edge. For this purpose, this research tries to find out major northeast asia environment factors and accordingly the effects of its. The effects of coastal shipping system's development strategy is analysed by structural equation model and multiple regression model. Research results show that three types of coastal shipping developing strategy(connected transportation system, structure of coastal shipping system, governmental support policy) will contribute much to be logistic hub-nation. The contribution effects is increasing cargo from strengthened feeder transport system and maximizing logistic service &minimizing logistic costs. From the result, some implications are derived as follow. First, familiar environmental balanced ocean-coastal transport system is required. Second the one-stop logistic service system is necessary to build excusive feeder port, and to establish Ro-Ro ship & high-speed ship, etc.. Third, governmental support policy and subsidy(tax exempted oil & various tax benefits) are required to bring up lagging behind coastal shipping system to be a logistic hub-nation with a competitive edge.

  • PDF

Patient-Specific Quality Assurance in a Multileaf Collimator-Based CyberKnife System Using the Planar Ion Chamber Array

  • Yoon, Jeongmin;Lee, Eungman;Park, Kwangwoo;Kim, Jin Sung;Kim, Yong Bae;Lee, Ho
    • Progress in Medical Physics
    • /
    • v.29 no.2
    • /
    • pp.59-65
    • /
    • 2018
  • This paper describes the clinical use of the dose verification of multileaf collimator (MLC)-based CyberKnife plans by combining the Octavius 1000SRS detector and water-equivalent RW3 slab phantom. The slab phantom consists of 14 plates, each with a thickness of 10 mm. One plate was modified to support tracking by inserting 14 custom-made fiducials on surface holes positioned at the outer region of $10{\times}10cm^2$. The fiducial-inserted plate was placed on the 1000SRS detector and three plates were additionally stacked up to build the reference depth. Below the detector, 10 plates were placed to avoid longer delivery times caused by proximity detection program alerts. The cross-calibration factor prior to phantom delivery was obtained by performing with 200 monitor units (MU) on the field size of $95{\times}92.5mm^2$. After irradiation, the measured dose distribution of the coronal plane was compared with the dose distribution calculated by the MultiPlan treatment planning system. The results were assessed by comparing the absolute dose at the center point of 1000SRS and the 3-D Gamma (${\gamma}$) index using 220 patient-specific quality assurance (QA). The discrepancy between measured and calculated doses at the center point of 1000SRS detector ranged from -3.9% to 8.2%. In the dosimetric comparison using 3-D ${\gamma}$-function (3%/3 mm criteria), the mean passing rates with ${\gamma}$-parameter ${\leq}1$ were $97.4%{\pm}2.4%$. The combination of the 1000SRS detector and RW3 slab phantom can be utilized for dosimetry validation of patient-specific QA in the CyberKnife MLC system, which made it possible to measure absolute dose distributions regardless of tracking mode.

Data Build-up for the Construction of Korean Specific Greenhouse Gas Emission Inventory in Livestock Categories

  • Won, S.G.;Cho, W.S.;Lee, J.E.;Park, K.H.;Ra, C.S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.27 no.3
    • /
    • pp.439-446
    • /
    • 2014
  • Many studies on methane ($CH_4$) and nitrous oxide ($N_2O$) emissions from livestock industries have revealed that livestock production directly contributes to greenhouse gas (GHG) emissions through enteric fermentation and manure management, which causes negative impacts on animal environment sustainability. In the present study, three essential values for GHG emission were measured; i.e., i) maximum $CH_4$ producing capacity at mesophilic temperature ($37^{\circ}C$) from anaerobically stored manure in livestock category ($B_{0,KM}$, Korean livestock manure for $B_0$), ii) $EF_{3(s)}$ value representing an emission factor for direct $N_2O$ emissions from manure management system S in the country, kg $N_2O-N$ kg $N^{-1}$, at mesophilic ($37^{\circ}C$) and thermophilic ($55^{\circ}C$) temperatures, and iii) $N_{ex(T)}$ emissions showing annual N excretion for livestock category T, kg N $animal^{-1}$ $yr^{-1}$, from different livestock manure. Static incubation with and without aeration was performed to obtain the $N_2O$ and $CH_4$ emissions from each sample, respectively. Chemical compositions of pre- and post- incubated manure were analyzed. Contents of total solids (% TS) and volatile solid (% VS), and the ratio of carbon to nitrogen (C/N) decrease significantly in all the samples by C-containing biogas generation, whereas moisture content (%) and pH increased after incubation. A big difference of total nitrogen content was not observed in pre- and post-incubation during $CH_4$ and $N_2O$ emissions. $CH_4$ emissions (g $CH_4$ kg VS-1) from all the three manures (sows, layers and Korean cattle) were different and high C/N ratio resulted in high $CH_4$ emission. Similarly, $N_2O$ emission was found to be affected by % VS, pH, and temperature. The $B_{0,KM}$ values for sows, layers, and Korean cattle obtained at $37^{\circ}C$ are 0.0579, 0.0006, and 0.0828 $m^3$ $CH_4$ kg $VS^{-1}$, respectively, which are much less than the default values in IPCC guideline (GL) except the value from Korean cattle. For sows and Korean cattle, $N_{ex(T)}$ values of 7.67 and 28.19 kg N $yr^{-1}$, respectively, are 2.5 fold less than those values in IPCC GL as well. However, $N_{ex(T)}$ value of layers 0.63 kg N $yr^{-1}$ is very similar to the default value of 0.6 kg N $yr^{-1}$ in IPCC GLs for National greenhouse gas inventories for countries such as South Korea/Asia. The $EF_{3(s)}$ value obtained at $37^{\circ}C$ and $55^{\circ}C$ were found to be far less than the default value.

A Study on the Development and Measurement of Logistics Partners Cooperation Index(LPCI): Focused on the Joint Logistics (물류협력지수의 개발 및 측정에 관한 연구: 공동물류사업을 중심으로)

  • Suh, Sang-Sok;Song, Gwang-Suk;Park, Jong-Woo
    • Journal of Distribution Science
    • /
    • v.14 no.6
    • /
    • pp.107-118
    • /
    • 2016
  • Purpose - Over 90% of Domestic logistics industry is small enterprise and they are experiencing growth stagnation due to price-based competition structure rather than constructing logistics service of high added value. In order to get over this situation and pursue the development of logistics industry, strengthening its competitiveness, through inter-enterprise cooperative network build-up, would be a key alternative. Therefore, in this study, an index for measuring inter-enterprise cooperation level of Joint logistics business will be developed as a typical collaborative business model in logistics industry. Moreover, a strengthening competitiveness method suggests a developmental step and a key management index to mature in logistics industry. Research Design, Data, Methodology - This study is an index development research for measuring inter-enterprise cooperation level of logistics industry. Such a level was measured by performing a survey by targeting enterprises that participated in Joint logistics business. The targeting enterprises are typical cooperative models in logistics industry. Measurement items were developed which were based on the presented items in existing research. Question items were composed of selection type questions as answering Yes/No. They measures implementation status of corporate activity and detailed activity items measuring qualitative level. Total samples were based on 116 enterprise samples including 90 logistics enterprises and 26 shippers. In addition, by evaluating the importance for Joint logistics business recognition with personnel working level, the weight of measuring variable was extracted. This study has built an assessment tools (LPCI) on Joint logistics business cooperation level in a situation where there are no previous studies on joint logistics business, this study is meaningful for other studies. Results - As a result of analyzing LPCI presented in this study, the score of logistics enterprise was represented as 59.9 points based on full score of 100 points and that of shippers as 47.2 points and cooperation level among enterprises participated in Joint logistics business was revealed to be very low. In particular, as a result of measuring the importance between logistics enterprise and shippers, the difference by each measurement standard was represented among those enterprises. This difference is considered to be a key factor that cooperative operational conformity between logistics enterprises and shippers is represented to be low. Conclusions - As most joint logistics business, being promoted at present, is sharing facility and information with joint logistics business, it is hard to find such a joint logistics business in reality based on cooperative business model in main cooperation agents. Therefore, competitiveness of logistics industry could be strengthened by promoting joint logistics business based on their mutual cooperation among enterprises. In other words, it is to secure sustainable competitiveness of joint logistics business together with creation of new market by inter-enterprise cooperation based on integration of basic logistics business.

Evaluation of marginal leakage of bulk fill flowable composite resin filling with different curing time using micro-computed tomography technology (Bulk fill 유동성 복합레진의 변연 누출에서 다른 중합시간의 영향에 대해 마이크로시티를 이용한 평가)

  • Kim, Eun-Ji;Lee, Kyu-Bok;Jin, Myoung-Uk
    • Journal of Dental Rehabilitation and Applied Science
    • /
    • v.32 no.3
    • /
    • pp.184-193
    • /
    • 2016
  • Purpose: To evaluate marginal leakage of bulk fill flowable composite resin filling with different curing time by using microcomputed tomography technology. Materials and Methods: 30 previously extracted human molars were randomly divided into 6 groups based upon restorative system and different curing time. Class II cavities (vertical slot cavities) were prepared. An individual metallic matrix was used to build up the proximal wall. The SonicFill or SureFil SDR flow was inserted into the preparation by using 1 bulk increment, followed by light polymerization for different curing times. The different exposure times were 20, 40, and 60 seconds. All specimens were submitted to 5,000 thermal cycles for artificial aging. Micro-CT scanning was performed by using SkyScan 1272. One evaluator assessed microleakage of silver nitrated solution at the resin-dentin interface. The 3D image of each leakage around the restoration was reconstructed with CT-Analyser V.1.14.4. The leakage was analyzed with the Mann-Whitney test. Results: Significant differences were observed between the light curing times, but no significant differences were found between the bulk fill composite resins. Increasing in the photoactivation time resulted in greater microleakage in all the experimental groups. Those subjected to 60 seconds of light curing showed higher microleakage means than those exposed for 20 seconds and 40 seconds. Conclusion: Increasing the photoactivation time is factor that may increase marginal microlekage of the bulk fill composite resins. Further, micro-CT can nondestructively detect leakage around the resin composite restoration in three dimensions.

Philippines 2017: Warlike Powers of Security Forces and Hedging Strategies in Foreign Relation (필리핀 2017: 호전적 내치(內治)와 줄타기 외교)

  • KIM, Dong-Yeob;JUNG, Bub Mo
    • The Southeast Asian review
    • /
    • v.28 no.2
    • /
    • pp.181-212
    • /
    • 2018
  • In 2017, the government of Duterte, in the second year of the ruling, more strongly promoted peace and order policies and expressed independent diplomacy as the chairman of ASEAN. He continued to fight against drugs and tried to increase his political legitimacy through the punishment for corrupt officials. He also declared martial law in the Mindanao region because of the dissolution of the Maute group, a Muslim terrorist organization, and strengthened counterterrorism cooperation externally. In addition, as to Communist militants, he took the initial reconciliation gesture and promoted peace negotiations, however, concluded the peace tide and started the suppression operation due to a series of bloodshed. He still has a strong drive in peace and order issues, backed up by high support rate, but it is becoming a factor of anxiety as the socioeconomically underprivileged and minority groups are increasingly alienated. As the chairman of ASEAN, Duterte has a certain distance from the United States, which is a firm ally, but has turned to increase familiarity with China and Russia, which can take substantial economic benefits. Through diversifying the external economic support and increase of tax revenue, the priority task was to establish the infrastructure. Although the Philippines, which has a high economic growth rate, has a strong expectation that it can establish a solid infrastructure, tax reforms should be successfully completed in order not to repeat the previous failures, which has traditionally increased foreign debt burden by relying on external resources. It seems that it is necessary to find the meeting point of the foreign policy of Duterte and new Korean government's New Southern Policy, and to find possible economic cooperation policies to improve Philippine infrastructure.

A Study on the Influence of Educational, Historical, and Tourism Characteristics of Suwon Hwaseong on Visiting Intention (수원 화성이 가지고 있는 교육성, 역사성, 관광성이 방문의도에 미치는 영향에 관한 연구)

  • Lee, Ji-Hun
    • Journal of Korea Entertainment Industry Association
    • /
    • v.14 no.1
    • /
    • pp.61-73
    • /
    • 2020
  • The purpose of this study is to investigate the relationship between educational attainment, history, tourism, psychological benefits, educational benefits, and hedonic benefits on visitors 'intention, and to provide Suwon Hwaseong' We propose a suggestion point. The implications of this study are as follows. First, the participants of Suwon Hwaseong Fortress are not only aware of the fact that the meaning of Mars is simply a stone build-up, but also a place to learn Korean history, experience various cultural experiences and attractions, Should be developed and made available to tourists. Second, the officials of Suwon Hwaseong Fortress should develop educational materials to understand the history of Mars as the representative history of Korean history. Furthermore, contents that show the superiority of Suwon Hwaseong in comparison with various world cultures It is necessary to provide policy support so that it can be developed and provided. Third, the officials of Suwon Hwaseong Fortress will have to worry about the development of culture prototype that can be excavated as a tourism factor when visitors visit and how to provide contents. In order to make sure that tourists do not inconvenience during sightseeing, It should be enough. Finally, the officials of Suwon Hwaseong should provide various entertainment factors around Hwaseong, and should try to create a desire to visit Hwaseong through a systematic PR method.