• Title/Summary/Keyword: scale-model

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Risk Assessment Model for the Delay Protocol in the Conditions of Contract of International Construction Projects (해외 건설공사 공기지연사건의 합리적 대응을 위한 계약조건 리스크 평가 방법)

  • Lee, Hwangku;Shin, Dongwoo;Kim, Kyungrai;Cha, Heesung;Kim, Youngjae
    • Korean Journal of Construction Engineering and Management
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    • v.18 no.6
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    • pp.65-77
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    • 2017
  • Recently, many Korean major construction companies are suffering from profit loss mainly due to a direct impact from delays in their overseas projects. In general, changes are inevitable in a large-scale project, and most of changes are directly linked to construction delay. Therefore, in the event that an extension of time is necessary due to a change, the contractor must manage the delay based on the condition of the contract to effectively manage risks from delay to the completion date. Thus it is important to understand delay protocol defined in the condition of the contract early in the project, but there have been few or no study to propose methodology or tool to support this effort. This paper presents a review on the project planning and controling practices of major Korean construction companies along with the issues on delay claims and disputes in mega-international projects and suggests a tool to assess delay risk in the condition of the contract. To propose a delay risk assessment model for international construction projects, major standard conditions of contract have been reviewed including FIDIC Red Book(1999), PSSCOC(2014) and SIA 9th Edition(2010). To reflect recent trend of major international owners, standard conditions which they are utilizing for their projects also have been reviewed including those of ARAMCO and QP. The model provides a categories of risks to be reviewed on the condition of the contract along with standard level of the risk which is common in the international standard form of the contracts. This study also performed a case study on an actual international project to confirm the effectiveness of proposed model to identify and respond to a delay risk of a project.

Estimation of Chlorophyll-a Concentrations in the Nakdong River Using High-Resolution Satellite Image (고해상도 위성영상을 이용한 낙동강 유역의 클로로필-a 농도 추정)

  • Choe, Eun-Young;Lee, Jae-Woon;Lee, Jae-Kwan
    • Korean Journal of Remote Sensing
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    • v.27 no.5
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    • pp.613-623
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    • 2011
  • This study assessed the feasibility to apply Two-band and Three-band reflectance models for chlorophyll-a estimation in turbid productive waters whose scale is smaller and narrower than ocean using a high spatial resolution image. Those band ratio models were successfully applied to analyzing chlorophyll-a concentrations of ocean or coastal water using Moderate Imaging Spectroradiometer(MODIS), Sea-viewing Wide Field-fo-view Sensor(SeaWiFS), Medium Resolution Imaging Spectrometer(MERIS), etc. Two-band and Three-band models based on band ratio such as Red and NIR band were generally used for the Chl-a in turbid waters. Two-band modes using Red and NIR bands of RapidEye image showed no significant results with $R^2$ 0.38. To enhance a band ratio between absorption and reflection peak, We used red-edge band(710 nm) of RapidEye image for Twoband and Three-band models. Red-RE Two-band and Red-RE-NIR Three-band reflectance model (with cubic equation) for the RapidEye image provided significance performances with $R^2$ 0.66 and 0.73, respectively. Their performance showed the 'Approximate Prediction' with RPD, 1.39 and 1.29 and RMSE, 24.8, 22.4, respectively. Another three-band model with quadratic equation showed similar performances to Red-RE two-band model. The findings in this study demonstrated that Two-band and Three-band reflectance models using a red-edge band can approximately estimate chlorophyll-a concentrations in a turbid river water using high-resolution satellite image. In the distribution map of estimated Chl-a concentrations, three-band model with cubic equation showed lower values than twoband model. In the further works, quantification and correction of spectral interferences caused by suspended sediments and colored dissolved organic matters will improve the accuracy of chlorophyll-a estimation in turbid waters.

Relationships among Brand Equity Components: An Exploratory Study of the Moderating Role of Product Type (품패자산조성부분간적상호관계(品牌资产组成部分间的相互关系): 관우산품충류조절작용적탐색연구(关于产品种类调节作用的探索研究))

  • Moon, Byeong-Joon;Park, Won-Kyu;Choi, Sang-Chul
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.1
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    • pp.98-109
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    • 2010
  • Research on the construction, measurement, and management of brand equity has been extensive since David A. Aaker(1991) and Kevin Lane Keller(1993) first advanced the concept. Recently, much attention has been devoted to the components of brand equity: brand awareness, perceived quality, brand image, and brand loyalty. This study explores the relationships among these components, focusing particularly on the moderating role of product type (utilitarian vs. hedonic) in their causal relationships. A model to study the relationship among components of brand equity, particularly the moderating role of product type, is featured in Figure 1. The hypotheses of the study are proposed as follows: that consumers' brand awareness has a positive influence on brand loyalty and brand image; that consumers' perceived quality has a positive influence on brand loyalty and brand image; that consumers' brand image influences brand loyalty positively; and that relationships among components of brand equity will be moderated by product type. That is, in the case of utilitarian products, the impact of perceived quality on brand loyalty will be relatively stronger, whereas with hedonic products the impact of brand image on brand loyalty will be relatively stronger. To determine the products for the study, a pre-test of 58 college students in the Seoul metropolitan area was conducted based on the product type scale. As a result, computers were selected as the utilitarian product and blue jeans became the hedonic product. For each product type, two brands were selected: Samsung and HP for computers, and Levis and Nix for blue jeans. In the main study, 237 college students in the metropolitan area were surveyed to measure their brand awareness, perceived quality, brand image, and brand loyalty toward the selected two brands of each product type. The subjects were divided into two groups: one group (121 subjects) for computers, the other (116 subjects) for blue jeans. The survey questionnaires for the study included four parts: five questions on brand awareness and four questions each on perceived quality, brand image, and brand loyalty. All questions were to be answered using 7-point Likert scales. The data collected by the survey were processed to assess reliability and validity, and the causal relationships were analyzed to verify the hypotheses using the AMOS 7 program, a tool for analyzing structural equation modeling. A confirmatory factor analysis assessed the appropriateness of the measurement model, and the fit indices denoted that the model was satisfactory. The relationships among the components of brand equity were also analyzed using AMOS 7. The fit indices of the structural model denoted that it was also satisfactory. The paths in the structural model as will be seen in Figure 2 show that perceived quality affects brand image positively, but that brand awareness does not affect brand image. Moreover, it shows that brand awareness, perceived quality, and brand image are positively related with brand loyalty, and that this relationship is moderated by product type. In the case of utilitarian products, perceived quality has relatively more influence on brand loyalty. Conversely, in the case of hedonic products, brand image has relatively more influence on brand loyalty. The results of this empirical study contribute toward the advancement of our understanding of the relationships among the components of brand equity and expand the theoretical underpinnings for brand equity measurement. It also helps further our understanding of the effect of product type on customer-based brand equity. In a marketing management practice perspective, these results may provide managerial implications for building and maintaining brand equity effectively.

A Prediction Model for Removal of Non-point Source Pollutant Considering Clogging Effect of Sand Filter Layers for Rainwater Recycling (빗물 재활용을 위한 모래 정화층의 폐색특성을 고려한 비점오염원 제거 예측 모델 연구)

  • Ahn, Jaeyoon;Lee, Dongseop;Han, Shinin;Jung, Youngwook;Choi, Hangseok
    • Journal of the Korean Geotechnical Society
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    • v.30 no.6
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    • pp.23-39
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    • 2014
  • An artificial rainwater reservoir installed in urban areas for recycling rainwater is an eco-friendly facility for reducing storm water effluence. However, in order to recycle the rainwater directly, the artificial rainwater reservoir requires an auxiliary system that can remove non-point source pollutants included in the initial rainfall of urban area. Therefore, the conventional soil filtration technology is adopted to capture non-point source pollutants in an economical and efficient way in the purification system of artificial rainwater reservoirs. In order to satisfy such a demand, clogging characteristics of the sand filter layers with different grain-size distributions were studied with real non-point source pollutants. For this, a series of lab-scale chamber tests were conducted to make a prediction model for removal of non-point source pollutants, based on the clogging theory. The laboratory chamber experiments were carried out by permeating two types of artificially contaminated water through five different types of sand filter layers with different grain-size distributions. The two artificial contaminated waters were made by fine marine-clay particles and real non-point source pollutants collected from motorcar roads of Seoul, Korea. In the laboratory chamber experiments, the concentrations of the artificial contaminated water were measured in terms of TSS (Total Suspended Solids) and COD (Chemical Oxygen Demand) and compared with each other to evaluate the performance of sand filter layers. In addition, the accumulated weight of pollutant particles clogged in the sand filter layers was estimated. This paper suggests a prediction model for removal of non-point source pollutants with theoretical consideration of the physical characteristics such as the grain-size distribution and composition, and change in the hydraulic conductivity and porosity of sand filter layers. The lumped parameter ${\theta}$ related with the clogging property was estimated by comparing the accumulated weight of pollutant particles obtained from the laboratory chamber experiments and calculated from the prediction model based on the clogging theory. It is found that the lumped parameter ${\theta}$ has a significant influence on the amount of the pollutant particles clogged in the pores of sand filter layers. In conclusion, according to the clogging prediction model, a double-sand-filter layer consisting of two separate layers: the upper sand-filter layer with the effective particle size of 1.49 mm and the lower sand-filter layer with the effective particle size of 0.93 mm, is proposed as the optimum system for removing non-point source pollutants in the field-sized artificial rainwater reservoir.

Structural Relationships Among Factors to Adoption of Telehealth Service (원격의료서비스 수용요인의 구조적 관계 실증연구)

  • Kim, Sung-Soo;Ryu, See-Won
    • Asia pacific journal of information systems
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    • v.21 no.3
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    • pp.71-96
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    • 2011
  • Within the traditional medical delivery system, patients residing in medically vulnerable areas, those with body movement difficulties, and nursing facility residents have had limited access to good healthcare services. However, Information and Communication Technology (ICT) provides us with a convenient and useful means of overcoming distance and time constraints. ICT is integrated with biomedical science and technology in a way that offers a new high-quality medical service. As a result, rapid technological advancement is expected to play a pivotal role bringing about innovation in a wide range of medical service areas, such as medical management, testing, diagnosis, and treatment; offering new and improved healthcare services; and effecting dramatic changes in current medical services. The increase in aging population and chronic diseases has caused an increase in medical expenses. In response to the increasing demand for efficient healthcare services, a telehealth service based on ICT is being emphasized on a global level. Telehealth services have been implemented especially in pilot projects and system development and technological research. With the service about to be implemented in earnest, it is necessary to study its overall acceptance by consumers, which is expected to contribute to the development and activation of a variety of services. In this sense, the study aims at positively examining the structural relationship among the acceptance factors for telehealth services based on the Technology Acceptance Model (TAM). Data were collected by showing audiovisual material on telehealth services to online panels and requesting them to respond to a structured questionnaire sheet, which is known as the information acceleration method. Among the 1,165 adult respondents, 608 valid samples were finally chosen, while the remaining were excluded because of incomplete answers or allotted time overrun. In order to test the reliability and validity of the assessment scale items, we carried out reliability and factor analyses, and in order to explore the causal relation among potential variables, we conducted a structural equation modeling analysis using AMOS 7.0 and SPSS 17.0. The research outcomes are as follows. First, service quality, innovativeness of medical technology, and social influence were shown to affect perceived ease of use and perceived usefulness of the telehealth service, which was statistically significant, and the two factors had a positive impact on willingness to accept the telehealth service. In addition, social influence had a direct, significant effect on intention to use, which is paralleled by the TAM used in previous research on technology acceptance. This shows that the research model proposed in the study effectively explains the acceptance of the telehealth service. Second, the research model reveals that information privacy concerns had a insignificant impact on perceived ease of use of the telehealth service. From this, it can be gathered that the concerns over information protection and security are reduced further due to advancements in information technology compared to the initial period in the information technology industry, and thus the improvement in quality of medical services appeared to ensure that information privacy concerns did not act as a prohibiting factor in the acceptance of the telehealth service. Thus, if other factors have an enormous impact on ease of use and usefulness, concerns over these results in the initial period of technology acceptance may become irrelevant. However, it is clear that users' information privacy concerns, as other studies have revealed, is a major factor affecting technology acceptance. Thus, caution must be exercised while interpreting the result, and further study is required on the issue. Numerous information technologies with outstanding performance and innovativeness often attract few consumers. A revised bill for those urgently in need of telehealth services is about to be approved in the national assembly. As telemedicine is implemented between doctors and patients, a wide range of systems that will improve the quality of healthcare services will be designed. In this sense, the study on the consumer acceptance of telehealth services is meaningful and offers strong academic evidence. Based on the implications, it can be expected to contribute to the activation of telehealth services. Further study is needed to assess the acceptance factors for telehealth services, such as motivation to remain healthy, health care involvement, knowledge on health, and control of health-related behavior, in order to develop unique services according to the categorization of customers based on health factors. In addition, further study may focus on various theoretical cognitive behavior models other than the TAM, such as the health belief model.

An Analysis of Factors Associated with Private Owner's Attitude toward Forest Management (사유림소유자(私有林所有者)의 시업의식(施業意識)에 영향(影響)을 미치는 제요인(諸要因)의 분석(分析))

  • Cho, Eung Hyouk
    • Korean Journal of Agricultural Science
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    • v.9 no.1
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    • pp.260-268
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    • 1982
  • The study has been carried out to investigate the relationship of certain factors to the private owners' attitudes toward forest management. The dependent variable is the attitude toward forest management, and the six independent variables are owner's age, educational level, forestland area, socioeconomic status, communicational and sociopsychological factors. The dependent variables were measured by Likert attitude scale. The data used in the study were obtained from 262 common-and model-forest owners, and analyzed primarily by multiple correlation statistical technique. Major findings of the study are summarized as follows; 1. The average score of common-owners' attitudes toward forest management is significantly lower than that of model-owners'. The scores of such independent variables as age, forestland area, socioeconomic status and communication of common-owners are also significantly lower than those of model-owners', while the significant difference of sociopsychological scores is not recognized between two owner groups. 2. The common-owners' attitudes toward forest management are negatively correlated with age variable, arid positively with other independent variables. On the other hand, the model-owners' are negatively correlated with education variable, arid positively with age, communicational and sociopsychological factors. 3. The multiple correlation coefficient between common-owner' management-attitude scores and six independent variables is 0.6971. About 41 percent of the variance of this attitude cart be explained by sociopsychological factor, and other 7 percent by communicational variable. In case of model-owners, the multiple correlation coefficient is 0.5207, and about 16.2 percent of the variance of the attitude can be explained by sociopsychological factor and 6 percent by age variable. 4. The multiple correlation coefficient between the attitude scores of all-owners arid such seven different personality factors as fatalistic, trustful, cooperative, ambitious, conservative, scientific and traditional familism personalities is 0.6566. In this case, 15 percent of the variance of the management-attitude can be explained by ambitious personality, and 11.2 percent by traditional familism. 5. The private forest owners' attitudes toward forest management are greatly affected by sociopsychological and communicational factors. The emphasis should be therefore put on the forestry extension works to induce private owners to management practices.

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Development and Application of an Evaluation Model for Biotope Appraisal as Related to Nature Experiences and Recreation (비오톱의 자연체험 및 휴양가치 평가모형 개발과 적용)

  • Cho, Hyun-Ju;Lee, Hyun-Taek;SaGong, Jung-Hee;Ra, Jung-Hwa
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.4
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    • pp.11-24
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    • 2010
  • The main focus of this research is the establishment of a systemic evaluation model based on objective evaluation indices, which are drawn to assess the experiencing of nature and recreational value at the level of the district unit. First of all, as a result of a literature review, a total of 10 indices can be drawn including vegetation structure, pavement rate, and hemeroby to evaluate an assessment of natural experiences and recreational value. Also, as a result of expert survey analysis, all evaluation index items were above 4.4, which is a high importance average. Hemeroby and unique landscape factor items in particular were above 5.8, which is very high. In addition, as a result of implementing a factor analysis to classify evaluation indices according to characteristics, three factors arise: 'landscape structure and quality of natural experience', 'typical availability', and 'quality of aesthetic and visual sense.' Based on the above survey analysis results, the 'quality of aesthetic and visual sense' was the highest, at 3.510. The classification 'landscape structure and quality of natural experience' was the lowest, at 3.035. A systemic value evaluation model was established by comprehensively analyzing these results. To verify the validity of the evaluation model drawn, real sites are selected and applied. First of all, as a result of a biotope types classification of sites, biotope type groups are classified into a total of 13 including the stream biotope while its subordinate biotope types are classified into a total of 61 groups. Lastly, as a result of biotope value evaluation, which was a previously established evaluation model, there are a total of 16 types including vegetation-abundant natural rivers and small-scale woodlands near forests in grade I. There are 9 types in grade II, 8 in grade III, 8 in grade IV, 19 in the least-valuable grade V.

Estimation of Groundwater Table using Ground Penetration Radar (GPR) in a Sand Tank Model and at an Alluvial Field Site (실내 모형과 현장 충적층에서 지하투과레이더를 이용한 지하수면 추정)

  • Kim, Byung-Woo;Kim, Hyoung-Soo;Choi, Doo-Houng;Koh, Yong-Kwon
    • The Journal of Engineering Geology
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    • v.23 no.3
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    • pp.201-216
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    • 2013
  • Ground penetrating radar (GPR) surveys were conducted in a sand tank model in a laboratory and at an alluvial field site to detect the groundwater table and to investigate the influence of saturation on GPR response in the unsaturated zone. In the sand tank model, the groundwater table and saturation in the sand layer were altered by injecting water, which was then drained by a valve inserted into the bottom of the tank. GPR vertical reflection profile (VRP) data were obtained in the sand tank model for rising and lowering of the groundwater table to estimate the groundwater table and saturation. Results of the lab-scale model provide information on the sensitivity of GPR signals to changes in the water content and in the groundwater table. GPR wave velocities in the vadose zone are controlled mainly by variations in water content (increased travel time is interpreted as an increase in saturation). At the field site, VRP data were collected to a depth of 220 m to estimate the groundwater table at an alluvial site near the Nakdong river at Iryong-ri, Haman-gun, South Korea. Results of the field survey indicate that under saturated conditions, the first reflector of the GPR is indicative of the capillary fringe and not the actual groundwater table. To measure the groundwater table more accurately, we performed a GPR survey using the common mid-point (CMP) method in the vicinity of well-3, and sunk a well to check the groundwater table. The resultant CMP data revealed reflective events from the capillary fringe and groundwater table showing hyperbolic patterns. The normal moveout correction was applied to evaluate the velocity of the GPR, which improved the accuracy of saturation and groundwater table information at depth. The GPR results show that the saturation information, including the groundwater table, is useful in assessing the hydrogeologic properties of the vadose zone in the field.

Correlations of Exogenous and Endogenous Components of Auditory ERPs to Psychometric Measures of Personality (청각 EPR의 내외생적 요소들과 성격의 상관에 관한 연구)

  • Park, Chang-Bum;Lee, Ji-Young;Chi, Sang-Eun;Park, Eun-Hye;Lee, Young-Hyuk;Kim, Hyun-Teak
    • Science of Emotion and Sensibility
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    • v.5 no.4
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    • pp.59-66
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    • 2002
  • This study was proposed as an exploratory study for understanding the biological bases and structures of three personality models: Eysenck's PEN model, Gray's BIS/BAS model, and Costa & McCrae's Five Factor Model, which was chosen as the major descriptive model regardless of its biological bases. Besides, Eysenck's impulsivity scale, IVE, was added to demonstrate the relationship of P and impulsivity. Concerning personality, most previous reports have explored the relationships between P300 and the introversion-extraversion of Eysenck's theory because of its putative biological bases. In the present study, forty-eight undergraduate took four personality batteries (ERQ-R, NEO-Pl-R, BIS/BAS, and IVE). Two types of oddball tasks including different stimulus duration were used to induce ERPs (50ms for task 1, 300ms for task 2). Distributional topographies of correlation coefficients with personality traits and ERP components were drawn, and considered for the consistent interpretation of the personality model structures. Even though all equivalences for extraversion of personality batteries showed similarities for their intra-correlation, their correlations with P3 amplitudes were dissociate. Eysenck's E might not be the proper psychometric measure for elucidating its biological bases. The present study supported the negative relationship of P3 amplitude and extraversion, which is the consensus of previous studies. Neuroticism and Psychoticism showed correlations with the earlier sensory processing components such as N1 and P2. This result might explain the reason why most of studies have failed to find biological connections relating them. Interaction between gender and personality traits should be considered for the interpretation of correlations. Two types of auditory stimulus duration had different sensitivity to personality traits.

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Impact of the Planning CT Scan Time on the Reflection of the Lung Tumor Motion (전산화단층촬영 주사시간(Scan Time)이 폐종양운동의 재현성에 미치는 영향 분석)

  • Kim Su Ssan;Ha Sung Whan;Choi Eun Kyung;Yi Byong Yong
    • Radiation Oncology Journal
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    • v.22 no.1
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    • pp.55-63
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    • 2004
  • Purpose : To evaluate the reflection of tumor motion according to the planning CT scan time. Material and Methods : A model of N-shape, which moved aiong the longitudinal axis during the ventilation caused by a mechanical ventilator, was produced. The model was scanned by planning CT, while setting the relative CT scan time (T: CT scan time/ventilatory period) to 0.33, 0.50, 0.67, 0.75, 1.00, 1.337, and 1.537. In addition, three patients with non-small cell lung cancer who received stereotactic radiosurgery In the Department of Radiation Oncology, Asan Medical Center from 03/19/2002 to 05/21/2002 were scanned. Slow (10 Premier, Picker, scan time 2.0 seconds per slice) and fast CT scans (Lightspeed, GE Medical Systems, with a scan time of 0.8 second per slice) were peformed for each patient. The magnitude of reflected movement of the N-shaped model was evaluated by measuring the transverse length, which reflected the movement of the declined bar of the model at each slice. For patients' scans, all CT data sets were registered using a stereotactic body frame scale with the gross tumor volumes delineated in one CT image set. The volume and three-dimensional diameter of the gross tumor volume were measured and analyzed between the slow and fast CT scans. Results : The reflection degree of longitudinal movement of the model increased in proportion to the relative CT scan times below 1.00 7, but remained constant above 1.00 T Assuming the mean value of scanned transverse lengths with CT scan time 1.00 T to be $100\%$, CT scans with scan times of 0.33, 0.50, 0.57, and 0.75 T missed the tumor motion by 30, 27, 20, and $7.0\%$ respectively, Slow (scan time 2.0 sec) and Fast (scan time 0.8 sec) CT scans of three patients with longitudinal movement of 3, 5, and 10 mm measured by fluoroscopy revealed the increases in the diameter along the longitudinal axis Increased by 6.3, 17, and $23\%$ in the slow CT scans. Conculsion : As the relative CT scan time increased, the reflection of the respiratory tumor movement on planning CT also Increased, but remained constant with relative CT scan times above 1.00 T When setting the planning CT scan time above one respiration period (>1.00 T), only the set-up margin is needed to delineate the planning target volume. Therefore, therapeutic ratio can be increased by reducing the radiation dose delivered to normal lung tissue.