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Neutron dosimetry depending on the number of portals for prostate cancer IMRT(Intensity-Modulated Radiation Therapy) (전립선암의 세기조절 방사선치료 시 조사문수별 중성자선량 평가)

  • Lee, Joo-Ah;Son, Soon-Yong;Min, Jung-Whan;Choi, Kwan-Woo;Na, Sa-Ra;Jeong, Hoi-Woun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.6
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    • pp.3734-3740
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    • 2014
  • The aim of this study was provide basic information and establish the criteria in radiation therapy planning by measuring the absorbed neutron dose of normal tissues and lesions according to the number of portals. From September 2013 to January 2014, 20 patients who were diagnosed with prostate cancer and were previously treated with radiation therapy were replanned retrospectively to measure the absorbed neutron dose distribution according to the number of portals. The absorbed neutron dose was measured in each of the 5, 7 and 9 portals using a 15 MV energy, which meant a therapeutic dose of 220 cGy. The optical stimulation luminescence dosimeter was separated by 20cm and 60cm away from the center of the field of view. As a result, the average radiation dose in the abdomen appeared to have a positive relationship with the number of portals, which was statistically significant (p<.05). The average radiation dose was $4.34{\pm}1.08$. The average radiation dose in the thyroid was $2.71{\pm}.37$. Although it showed a positive relationship with the number of portals, it did not have statistical significance. The number of portals and the neutron dose depending on the position showed a significant positive relationship, particularly in the abdomen. As a result of linear regression analysis, as the number of the portal increased in steps, the average volume of the neutrons increased significantly (0.416 times). In conclusion, efficient selection of the number of portals is needed considering the difference in the absorbed neutron dose in the normal tissues depending on the number of the portals.

It Doesn't Taste the same from Someone Else's Plate: The Influence of Culture in Interpersonal Retail Service Evaluations (별인적반자적미도불일양(别人的盘子的味道不一样): 문화대인제령수복무평개적영향(文化对人际零售服务评价的影响))

  • Spielmann, Nathalie;Kim, Ju-Ran
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.2
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    • pp.164-172
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    • 2010
  • This study reviews the influence of culture in interpersonal servicescapes by examining the restaurant retail setting. Two cultures (Canada and France) are surveyed in order to better understand their retail expectations towards interpersonal servicescapes. Using Hofstede's (1991) cultural dimensions to explain some of the differences between Canadian and French restaurant patrons, this study demonstrates a potentially interesting research avenue in the field of cross-cultural interpersonal services marketing. It demonstrates that cultural dimensions do not operate independently but interdependently. Understanding this can help retailers better explain complex service interactions between countries that may appear similar in terms of various socio-demographic features. In this exploratory research, a measure via exploratory factor analysis was developed, one that encompasses both the physical and service aspects common to interpersonal servicescape by using personality traits. This measure was tested in order to better understand the service expectations between two cultures, Canada and France. Five dimensional structures were uncovered in both cultures but with different traits and groupings. The differences between the traits uncovered and the overall Canadian and French personality structures find some explanation using Hofstede's (1991) cultural dimensions. The results of this survey point to a possible explanation as to why when services are transferred between cultures, the perceptions of them can be different and sometimes even lead to service failure. There are clearly some cultural differences between the Canadian and French consumers and their overall expectations regarding their consumption experience. Reviewing the first factor of the French and Canadian personality structures shows that the individualist/collectivist differences are apparent between the Canadian and the French cultures. The second dimension also has quite a few traits in common, five, all of which have the personal treatment aspect of the restaurant experience that a service provider would be responsible for: polite, respectful, and dedicated. Notable is that the French dimension does not include the authenticity or the hospitable aspect of the experience but includes even more features that are inherent to the personal interaction, such as charming and courteous. The third dimension of the Canadian and French structures reflects completely different expectations. Whereas the French dimension centers around energy and enthusiasm, the Canadian version is more laid-back and relaxed. There is extroversion in the French dimension to introversion in the Canadian dimension. This could be explained by differences on the Uncertainty Avoidance dimension as outlined by Hofstede (1991). The fourth dimension seems to confirm previously outlined cultural differences. Whereas Canadians, being a bit lower on uncertainty avoidance and power distance, prefer an intimate and private experience, the French continue to expect extraversion and inclusive features to their experience. The fifth dimension is in the French personality structure a clear expression of the high power distance society, where the roles of the players in the restaurant experience are clearly defined and the rules of engagement preserved. This study demonstrates that different cultures clearly do relate to different expectations regarding interpersonal services. This is apparent in the dimensions that come up in both the French and the Canadian personality structures, not only in terms of how different they are but also in with which cultural dimensions these can be explained. For interpersonal servicescapes, the use of personality traits is interesting as it allows for both physical and service features to be accounted for. Furthermore, the social component inherent to interpersonal servicescapes surfaces in most of the dimensions of the service personality structures. The quality of social exchanges is extremely important, and this even more so in cross-cultural situations, where the expec tations regarding the service experience may vary. As demonstrated by this research and using Hofstede's (1991) paradigm, not all societies will have the same expectations pertaining to the interpersonal services. Furthermore, the traditions surrounding the type of service can also have an impact on the service evaluations and differ between countries and cultures. However, using personality traits may also allow for retailers to see which service traits are common to two or more cultures where they seek to be present, and focus on these in the offering. The findings demonstrate the importance of the individualist and collectivist dimension for interpersonal servicescapes. This difference between the French and the Canadian personality structure is apparent in the most dominant dimension as well as within others. The findings are a step in explaining how retailers can transfer and then measure interpersonal services across cultures.

Review of Remote Sensing Studies on Groundwater Resources (원격탐사의 지하수 수자원 적용 사례 고찰)

  • Lee, Jeongho
    • Korean Journal of Remote Sensing
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    • v.33 no.5_3
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    • pp.855-866
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    • 2017
  • Several research cases using remote sensing methods to analyze changes of storage and dynamics of groundwater aquifer were reviewed in this paper. The status of groundwater storage, in an area with regional scale, could be qualitatively inferred from geological feature, surface water altimetry and topography, distribution of vegetation, and difference between precipitation and evapotranspiration. These qualitative indicators could be measured by geological lineament analysis, airborne magnetic survey, DEM analysis, LAI and NDVI calculation, and surface energy balance modeling. It is certain that GRACE and InSAR have received remarkable attentions as direct utilization from satellite data for quantification of groundwater storage and dynamics. GRACE, composed of twin satellites having acceleration sensors, could detect global or regional microgravity changes and transform them into mass changes of water on surface and inside of the Earth. Numerous studies in terms of groundwater storage using GRACE sensor data were performed with several merits such that (1) there is no requirement of sensor data, (2) auxiliary data for quantification of groundwater can be entirely obtained from another satellite sensors, and (3) algorithms for processing measured data have continuously progressed from designated data management center. The limitations of GRACE for groundwater storage measurement could be defined as follows: (1) In an area with small scale, mass change quantification of groundwater might be inaccurate due to detection limit of the acceleration sensor, and (2) the results would be overestimated in case of combination between sensor and field survey data. InSAR can quantify the dynamic characteristics of aquifer by measuring vertical micro displacement, using linear proportional relation between groundwater head and vertical surface movement. However, InSAR data might now constrain their application to arid or semi-arid area whose land cover appear to be simple, and are hard to apply to the area with the anticipation of loss of coherence with surface. Development of GRACE and InSAR sensor data preprocessing algorithms optimized to topography, geology, and natural conditions of Korea should be prioritized to regionally quantify the mass change and dynamics of the groundwater resources of Korea.

Numerical Examinations of Damage Process on the Chuteway Slabs of Spillway under Various Flow Conditions (여수로 방류에 따른 여수로 바닥슬래브의 손상 발생원인 수치모의 검토)

  • Yoo, Hyung Ju;Shin, Dong-Hoon;Kim, Dong Hyun;Lee, Seung Oh
    • Journal of Korean Society of Disaster and Security
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    • v.14 no.4
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    • pp.47-60
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    • 2021
  • Recently, as the occurrence frequency of sudden floods due to climate variability increased, the damage of aging chuteway slabs of spillway are on the rise. Accordingly, a wide array of field survey, hydraulic experiment and numerical simulation have been conducted to find the cause of damage on chuteway slabs. However, these studies generally reviewed the flow characteristics and distribution of pressure on chuteway slabs. Therefore the derivation of damage on chuteway slabs was relatively insufficient in the literature. In this study, the cavitation erosion and hydraulic jacking were assumed to be the causes of damage on chuteway slabs, and the phenomena were reproduced using 3D numerical models, FLOW-3D and COMSOL Multiphysics. In addition, the cavitation index was calculated and the von Mises stress by uplift pressure distribution was compared with tensile and bending strength of concrete to evaluate the possibility of cavitation erosion and hydraulic jacking. As a result of numerical simulation on cavitation erosion and hydraulic jacking under various flow conditions with complete opening gate, the cavitation index in the downstream of spillway was less than 0.3, and the von Mises stress on concrete was 4.6 to 5.0 MPa. When von Mises stress was compared with tensile and bending strength of concrete, the fatigue failure caused by continuous pressure fluctuation occurred on chuteway slabs. Therefore, the cavitation erosion and hydraulic jacking caused by high speed flow were one of the main causes of damage to the chuteway slabs in spillway. However, this study has limitations in that the various shape conditions of damage(cavity and crack) and flow conditions were not considered and Fluid-Structure Interaction (FSI) was not simulated. If these limitations are supplemented and reviewed, it is expected to derive more efficient utilization of the maintenance plan on spillway in the future.

The foundation and Characteristic on the Aesthetic of EuiJae Huh BaekRyun' Namjonghwa (의재(毅齋) 허백련(許百鍊) 남종화(南宗畵)의 예술심미 고찰)

  • Kim, Doyoung
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.3
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    • pp.1-8
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    • 2020
  • EuiJae Hu BaekRyun is a symbol of Honam Namjonghwa and is respected as a teacher of Honam culture. He is from JinDo and is a relative of Sochi Heo Ryun and a disciple of Misan Heo Hyeong. The spirit of traditional Namjongghwa and the dignity of painting faithful to its technique have been obtained by themselves, and have made it his own. EuiJae organized a 'Yeonjinhoe' in Gwangju to raise his students. After liberation, a house was built under Mudeungsan Mountain. And showed another aspect as a social educator who emphasized and practiced national spirit while being a tea ceremony man. He excelled in Chinese poetry and painting theory, and expressed a unique field in calligraphy. especially worked as an artist good at poetry, caligraphy, and painting. EuiJae showed exceptional talent, especially in landscape painting. His tendency to paint was to follow Ye Chan's technique of drawing with a dry brush, placing importance on the energy of learning, and constantly trying new experiments with the technique of gisaeng. The world of EuiJae's works can be divided into three periods, based on the signature using the trend of painting or the change of perspective pursued, the era of EuiJae, the era of EuiJaeSanin, and the era of EuiDoin, which had a tendency of independent painting. EuiJae's contribution surpassed the artistic historical assessment that he had formed a big stem for the authentic Namjongghwa of Korean painting culture, which was part of Oriental painting. And recognizing that he was a fundamental teacher connecting modern times through the actual scenery based on NamDohwa's universal spirit and regional characteristics and the creative succession of emotions, he should inherit his passion for artistic spirit and tradition and experimental spirit.

Development of Bicycle Accident Prediction Model and Suggestion of Countermeasures on Bicycle Accidents (자전거 사고예측모형 개발 및 개선방안 제시에 관한 연구)

  • Kwon, Sung-Dae;Kim, Yoon-Mi;Kim, Jae-Gon;Ha, Tae-Jun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.5
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    • pp.1135-1146
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    • 2015
  • This thesis aims to improve the safety of bicycle traffic for activating the use of bicycle, main means of non-powered and non-carbon transportation in order to cope with worldwide crisis such as climate change and energy depletion and to implement sustainable traffic system. In this regard, I analyzed the problem of bicycle roads currently installed and operated, and developed the bicycle accident forecasting model. Following are the processes for this. First, this study presented the current status of bicycle road in Korea as well as accident data, collect the data on bicycle traffic accidents generated throughout the country for recent 3 years (2009~2011) and analyzed the features of bicycle traffic accidents based on the data. Second, this study selected the variable affecting the number of bicycle accidents through accident feature analysis of bicycle accidents at Jeollanam-do, and developed accident forecast model using the multiple regression analysis of 'SPSS Statistics 21'. At this time, the number of accidents due to extension per road types (crossing, crosswalk, other single road) was used. To verify the accident forecast model deduced, this study used the data on bicycle accident generated in Gwangju, 2011, and compared the prediction value with actual number of accidents. As a result, it was found out that reliability of accident forecast model was secured through reconciling with actual number of cases except certain data. Third, this study carried out field survey on the bicycle road as well as questionnaire on satisfaction of bicycle road and use of bicycle for analysis of bicycle road problems, and presented safety improvement measures for the problems deduced as well as bicycle activation plans. This study is considered to serve as the fundamental data for planning and reorganizing of bicycle road in the future, and expected to improve safety of bicycle users and to promote activation of bicycle use as the means of transportation.

The Study of Affecting Image Quality according to forward Scattering Dose used Additional Filter in Diagnostic Imaging System (부가필터 사용 시 전방 산란선량에 따른 화질 영향에 대한 연구)

  • Choi, Il-Hong;Kim, Kyo-Tae;Heo, Ye-Ji;Park, Hyong-Hu;Kang, Sang-Sik;Noh, Si-Cheol;Park, Ji-Koon
    • Journal of the Korean Society of Radiology
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    • v.10 no.8
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    • pp.597-602
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    • 2016
  • Recent clinical field utilizes the aluminium filter in order to reduce the low-energy photons. However, the usage of the filter can cause adverse effect on the image quality because of the scattered dose that is generated by X-ray hardening phenomenon. Further, usage of filter with improper thickness can be a reason of dose creep phenomenon where unnecessary exposure is generated towards the patient. In this study, the author evaluated the RMS and the RSD analysis in order to have a quantitative evaluation for the effect of forward scattering dose by the filter on the image. as a result of the study, the FSR and the RSD was increased together with the increasing of thickness of the filter. In this study the RSD means the standard deviation of the mean value is relatively size. It can be understood that the signal-to-noise ratio decreases when the average value is taken as a signal and the standard deviation is judged as a noise. The signal-to-noise ratio can understanding as index of resolution at image. Based on these findings, it was quantitatively verified that there is a correlation of the image quality with the FSR by using an additional filter. The results, a 2.5 mmAl which is as recommended by NCRP in the tube voltage of 70 kVp or more showed the 14.6% on the RSD when the filter was not in used. these results are considered able to be utilized as basic data for the study about the filter to improve the quality of the image.

The Neutralization Treatment of Waste Mortar and Recycled Aggregate by Using the scCO2-Water-Aggregate Reaction (초임계이산화탄소-물-골재 반응을 이용한 폐모르타르와 순환골재의 중성화 처리)

  • Kim, Taehyoung;Lee, Jinkyun;Chung, Chul-woo;Kim, Jihyun;Lee, Minhee;Kim, Seon-ok
    • Economic and Environmental Geology
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    • v.51 no.4
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    • pp.359-370
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    • 2018
  • The batch and column experiments were performed to overcome the limitation of the neutralization process using the $scCO_2$-water-recycled aggregate, reducing its treatment time to 3 hour. The waste cement mortar and two kinds of recycled aggregate were used for the experiment. In the extraction batch experiment, three different types of waste mortar were reacted with water and $scCO_2$ for 1 ~ 24 hour and the pH of extracted solution from the treated waste mortar was measured to determine the minimum reaction time maintaining below 9.8 of pH. The continuous column experiment was also performed to identify the pH reduction effect of the neutralization process for the massive recycled aggregate, considering the non-equilibrium reaction in the field. Thirty five gram of waste mortar was mixed with 70 mL of distilled water in a high pressurized stainless steel cell at 100 bar and $50^{\circ}C$ for 1 ~ 24 hour as the neutralization process. The dried waste mortar was mixed with water at 150 rpm for 10 min. and the pH of water was measured for 15 days. The XRD and TG/DTA analyses for the waste mortar before and after the reaction were performed to identify the mineralogical change during the neutralization process. The acryl column (16 cm in diameter, 1 m in length) was packed with 3 hour treated (or untreated) recycled aggregate and 220 liter of distilled water was flushed down into the column. The pH and $Ca^{2+}$ concentration of the effluent from the column were measured at the certain time interval. The pH of extracted water from 3 hour treated waste mortar (10 ~ 13 mm in diameter) maintained below 9.8 (the legal limit). From XRD and TG/DTA analyses, the amount of portlandite in the waste mortar decreased after the neutralization process but the calcite was created as the secondary mineral. From the column experiment, the pH of the effluent from the column packed with 3 hour treated recycled aggregate kept below 9.8 regardless of their sizes, identifying that the recycled aggregate with 3 hour $scCO_2$ treatment can be reused in real construction sites.

A Study on Electron Dose Distribution of Cones for Intraoperative Radiation Therapy (수술중 전자선치료에 있어서 선량분포에 관한 연구)

  • Kang, Wee-Saing;Ha, Sung-Whan;Yun, Hyong-Geun
    • Progress in Medical Physics
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    • v.3 no.2
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    • pp.1-12
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    • 1992
  • For intraoperative radiation therapy using electron beams, a cone system to deliver a large dose to the tumor during surgical operation and to save the surrounding normal tissue should be developed and dosimetry for the cone system is necessary to find proper X-ray collimator setting as well as to get useful data for clinical use. We developed a docking type of a cone system consisting of two parts made of aluminum: holder and cone. The cones which range from 4cm to 9cm with 1cm step at 100cm SSD of photon beam are 28cm long circular tubular cylinders. The system has two 26cm long holders: one for the cones larger than or equal to 7cm diamter and another for the smaller ones than 7cm. On the side of the holder is an aperture for insertion of a lamp and mirror to observe treatment field. Depth dose curve. dose profile and output factor at dept of dose maximum. and dose distribution in water for each cone size were measured with a p-type silicone detector controlled by a linear scanner for several extra opening of X-ray collimators. For a combination of electron energy and cone size, the opening of the X-ray collimator was caused to the surface dose, depths of dose maximum and 80%, dose profile and output factor. The variation of the output factor was the most remarkable. The output factors of 9MeV electron, as an example, range from 0.637 to 1.549. The opening of X-ray collimators would cause the quantity of scattered electrons coming to the IORT cone system. which in turn would change the dose distribution as well as the output factor. Dosimetry for an IORT cone system is inevitable to minimize uncertainty in the clinical use.

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Characteristics of Hydrodynamics, Heat and Mass Transfer in Three-Phase Inverse Fluidized Beds (삼상 역 유동층의 수력학, 열전달 및 물질전달 특성)

  • Kang, Yong;Lee, Kyung Il;Shin, Ik Sang;Son, Sung Mo;Kim, Sang Done;Jung, Heon
    • Korean Chemical Engineering Research
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    • v.46 no.3
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    • pp.451-464
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    • 2008
  • Three-phase inverse fluidized bed has been widely adopted with its increasing demand in the fields of bioreactor, fermentation process, wastewater treatment process, absorption and adsorption processes, where the fluidized or suspended particles are small or lower density comparing with that of continuous liquid phase, since the particles are frequently substrate, contacting medium or catalyst carrier. However, there has been little attention on the three-phase inverse fluidized beds even on the hydrodynamics. Needless to say, the information on the hydrodynamics and transport phenomena such as heat and mass transfer in the inverse fluidized beds has been essential for the operation, design and scale-up of various reactors and processes which are employing the three-phase inverse beds. In the present article, thus, the information on the three-phase inverse fluidized beds has been summarized and reorganized to suggest a pre-requisite knowledge for the field work in a sense of engineering point of view. The article is composed of three parts; hydrodynamics, heat and mass transfer characteristics of three-phase inverse fluidized beds. Effects of operating variables on the phase holdup, bubble properties and particle fluctuating frequency and dispersion were discussed in the section of hydrodynamics; effects of operating variables on the heat transfer coefficient and on the heat transfer model were discussed in the section of heat transfer characteristics ; and in the section of mass transfer characteristics, effects of operating variables on the liquid axial dispersion and volumetric liquid phase mass transfer coefficient were examined. In each section, correlations to predict the hydrodynamic characteristics such as minimum fluidization velocity, phase holdup, bubble properties and particle fluctuating frequency and dispersion and heat and mass transfer coefficients were suggested. And finally suggestions have been made for the future study for the application of three-phase inverse fluidized bed in several available fields to meet the increasing demands of this system.