• The Korean Journal of Nuclear Medicine Technology
• /
• v.18 no.1
• /
• pp.98-103
• /
• 2014

Purpose: The effective half life of I-131 is useful to calculate radiation dose, period of hospitalization, and exposure dose of surrounding people from patient. However, it is difficult to measure. This study estimates the effective half life in whole body and thyroid in using of value of residual radioactivity obtained from the early and delay images of Dual time I-131 whole body scan. Also, the correlations between the effective half life and serum creatinine, GFR, and administration dose were investigated in this study. Materials and Methods: The targets were 50 patients administration high dose of I-131 from February to August in 2013, having normal range of serum creatinine and over $30{\mu}IU/mL$ of TSH levels. After administration radioactive I-131, the early scan in the 3rd day and the delay scan in the 5-6th days were performed. To measure the residual radioactivity in the whole body and thyroid, ROI was set and then background radioactivity was corrected to estimate. The effective half life was estimated by calculating the ratio of measured values between the early and delay images. To compare the effective half lives of the whole body and thyroid, it was analyzed by Independent t-test, and each correlation of the effective half life, GFR, serum creatinine, and the dose of administration were analyzed by calculating the pearson's correlation coefficient. All of the analysis were determined to be statistically significant when P<0.05. Results: The effective half life of the whole body was $17.06{\pm}5.50$ hours and of the thyroid was $17.22{\pm}5.41$ hours. The two effective half life did not show significant difference (P=0.887). As the value of GFR was increased, the effective half life of whole body (r=-0.407, P=0.003) and of thyroid (r=-0.473, P=0.001) were significantly decreased; as the value of serum creatinine was increased, the effective half life of whole body (r=0.309, P=0.029) and of thyroid (r=0.371, P=0.008) were significantly increased. In the administration dose, effective half life did not have correlations. Conclusion: The effective half life of I-131 of patients treated for their thyroids were estimated only by using the images of Dual time I-131 whole body scan. Also, the correlations with the effective life, GFR, and serum creatinine were examined. This study might be utilized for a study on optimization for the period of hospitalization of patients treated by high dose of I-131 and on evaluation for internal absorbed dose of MIRD schema in application of the effective half life.

• Journal of the Korea Concrete Institute
• /
• v.20 no.2
• /
• pp.185-191
• /
• 2008

To fundamentally solve the problem of deterioration of concrete structures, it has been researched that the high durable concrete structure reinforced with the FRP rebar can be one of major solution to the newly-developed concrete structure. FRP rebar has lots of advantages such as non-corrosive, high performance and light weight against the conventional steel rebar. Among these kinds of FRP rebars, GFRP rebar has usually been considered as the best reinforcement because of its economic point of view. Even though the material capacity of the GFRP rebar was already investigated, there are some problems such as low modulus of elastic that will be cause for degrade of the serviceability of flexural concrete member reinforced with the GFRP rebar. Thus, the deflection characteristics of the GFRP rebar reinforced concrete structure should be considered then investigated. In this study, ACI 440 guideline (2003), ISIS Canada Design Manual (2001) and Toutanji et al. (2000) was considered for predicting the moment of inertia of the concrete beam reinforced with the GFRP rebar. And it was also evaluated that load-deflection relationship had a good accordance with the test and analysis result. In the result of this study, it could be estimated that the load-deflection relationship using the suggested equation of moment of inertia in this study indicated better accordance with the test result than that of the others until failure.

• 재활복지
• /
• v.17 no.4
• /
• pp.291-309
• /
• 2013

Web usability is utilized as a standard for constructing and managing website to be useful by people of all abilities and disabilities. Link integrity is one of main criteria for web usability evaluation. Links that are found to be broken or pointing to irrelevant information lead gradual degradation of link integrity over time. This study has conducted investigation for link integrity of Korean public institution website. Among 49 website that are accessible by an automatic link checker software, 91.8% of the website has more than one broken links. Also average number of broken links is 50.5 that is 0.33% of the number of links. 29 websites consist of internal broken links. And 22 website do not provide any information on the missing page. Broken links enlower website confidence by reducing web usability as well as they prohibit web search engine not to provide information on the website. Therefore, web developers and managers need to be aware of importance of link integrity and prohibit web usability degradation by performing link validation as a web management task or periodically.

• Journal of the Korean Society of Radiology
• /
• v.15 no.2
• /
• pp.139-145
• /
• 2021

This study is to confirm the range of tube voltage for Chest X-ray in DR system by comparing with dose area product (DAP) and effective dose in efficient detector exposure index (DEI) range. GE definium 8000 was used to for the phantom study. The range of tube voltage is 60~130 kVp and of mAs is 2.5~40 mAs. The acquired images were classified into efficient DEI groups, then calculated effective dose with DAP by using a PC-Based Monte Carlo Program 2.0. The signal to noise ratio (SNR) was measured at 4 regions, including the thoracic spine, the lung area with the ribs, the lung area without the ribs, and the liver by using Picture Archiving and Communication System. The significance of the group for each tube voltage was verified by performing the kruskal-wallis test and the mann-whitney test as a post-test. When set to 4 groups dependned on the tube voltage, DAP showed significant differences; 60 kVp and 80 kVp, and 60 kVp and 90 kVp (p= 0.034, 0.021). Effective dose exhibited no statistically significant differences from the all of the group (p>0.05). SNR exhibited statistically significant differences from the all of the group in the liver except compared to 80 kVp and 90 kVp (p<0.05). Therefore, high tube voltages of 100 kVp or more need to be reconsidered in terms of patient dose and imaging in order to represent an appropriate chest X-ray image in a digital system.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2009.04a
• /
• pp.567-572
• /
• 2009

본 연구에서는 국외 설계사무실과 국내 설계사무실의 수행 프로젝트(표1)를 디지털 디자인 프로세스에서의 디지털 도구 활용 사례조사 결과를 일련의 설계 프로세스(기획(Pre-Design), 계획 설계(Schematic Design) 중간설계(Detail Design), 실시설계(Construction Design))를 11개의 설계 단위작업((1)자료수집, (2)도서화작업, (3)의사소통/프레젠테이션, (4)협력업체와의 협업, (5)디자인 실험, (6)디자인분석/유효성 검토, (7)빌딩시스템과 자재선정, (8)자재비교/견적, (9)디자인 발전, (10)RP를 이용한 모델 제작, (11)시공/제작)으로 분류하여(설계프로세스별로 디지털 디자인 툴의 활용 빈도를 조사 분석하는 것은 프로세스별로 중복된 설계 단위작업이 진행됨으로 연구결과의 의미가 잘못 해석될 수 있다.) 그 활용에 대한 유형을 분석하고 이를 바탕으로 설계과정에서의 디지털 디자인 툴의 활용특성을 도출하여 실무설계의 기초자료를 제공하는데 그 목적을 둔다.

• Journal of the Society of Disaster Information
• /
• v.7 no.4
• /
• pp.247-258
• /
• 2011

In this study, both domestic ground and maritime environmental standard and treated method for beneficial use of dredged materials were investigated. To suggest beneficial use of dredged material, cemented bricks and light-weighted bricks were made. The strength of bricks was satisfied with the standard(50kPa), which is the strength for the reclamation work on the reclaimed land.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.12 no.2
• /
• pp.120-131
• /
• 2009

This study measured the centripetal force and effective scope of the population spread from urban center and subcenters in order to diagnose the urban spatial structure of the formation of a multicentric city structure in Busan. The study analyzed the variability of the determination coefficient value (R square) with a negative exponential function derived from the population density model by extending the circular region into 5-km units. The aim of this study was to measure changes in the effective scope of the population centripetal force of the urban center and subcenter in 5-year intervals from 1995 to 2005 using census data. The explanatory adequacy of the population density function was examined with the bias of the function to calculate the distance error between the real location of the urban center and the optimal location, according to the population density function. To summarize the results, the value for the area of Jungangdong showed a continuous reduction, whereas Seomyeon (Bujeondong) maintained explanatory adequacy without a large change. As a whole, Busan was in the process of continuous diversification, in spite of its reduced population. Therefore, it appears necessary to strengthen the function of the urban center and subcenter and to supply adequate dwelling zones close to downtown to form a more efficient urban spatial structure. The results of the present study will be utilized as basic data for the formulation of a political approach to the efficient reorganization of spatial structure by correlating concrete spatial information with the population variability of Busan's urban center and subcenter.

• Convergence Security Journal
• /
• v.14 no.6_2
• /
• pp.73-81
• /
• 2014

This study has an objective to analyze the causal relationship between the emotional labor of the members in the private security firms and its effect on their job stress and validity of the organization. To carry out the study, I established a population of private security guards working at the security firms in Seoul. Then a total of 700 question naires were sent out for the survey using the random sampling method of clusters. The study was carried out over about four months, from May, 2014 to September, 2014. A total of 676 questionnaires were used for the final data. 24 questionnaires were excluded either because they were not returned or contained extreme value. In this study, a statistical package of SPSSWIN 18.0 and AMOS 18.0 were used in the data analysis and the causal relationship was verified using the covariance structural equation. The analysis showed the emotional labor to have a positive effect on the validity of organization but a negative effect on the job stress at the statistical level of p<.001 and the hypothesis was adopted. The hypothesis regarding the job stress was also adopted because job stress was found to have a negative effect on the validity of organization at the statistical level of p<.001. In addition, job stress was found to have a negative effect on the relationship between the emotional labor and validity of organization at the statistical level of p<.001. As a result, the hypothesis about the job stress would function as the parameter was only partially adopted.

• Journal of IKEEE
• /
• v.25 no.2
• /
• pp.388-398
• /
• 2021

This paper proposes a particle swarm optimization (PSO)-based peak shaving scheme using energy storage system (ESS) for electricity tariff reduction. The proposed scheme compares the actual load with the estimated load consumption, calculates the additional output power that the ESS needs to discharge additionally to reduce peak load, and adds the input. In addition, in order to compensate for the additional power, the process of allocating power to the determined point is performed, and an optimization that minimizes the average of the load expected at the active power allocations using PSO so that the allocated value does not affect the peak load. To investigated the performance of the proposed scheme, case study of small and large load prediction errors was conducted by reflecting actual load data and load prediction algorithm. As a result, when the proposed scheme is performed with the ESS charge and discharge control to reduce electricity tariff, even when the load prediction error is large, the peak load is successfully reduced, and the peak load reduction effect of 17.8% and electricity tariff reduction effect of 6.02% is shown.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.3
• /
• pp.231-240
• /
• 2016

Recently, fake test data of power cables in nuclear power plants was a terrible shock to the citizens. Some cable companies manipulated the test data to make unfair profits. In addition, fake test data cases were found in military supplies. The fake test data cases focused on parts of army's tank, armored car. This paper propose a new method that can detect fake test data using known statistical methods. In addition, the method was implemented in Microsoft Excel to allow easy use. Lastly, a check sheet was proposed to check the validity of the test system of military suppliers. By detecting and checking the fake test data, it is expected that our new method will play an important role in quality assurance of military supplies.