• Title/Summary/Keyword: T-test analysis

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Fingerprint of Carcinogenic Semi-Volatile Organic Compounds (SVOCs) during Bonfire Night

  • Pongpiachan, Siwatt
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.5
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    • pp.3243-3254
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    • 2013
  • It is well known that increased incidences of lung, skin, and bladder cancers are associated with occupational exposure to PAHs. Animal studies show that certain PAHs also can affect the hematopoietic and immune systems and can produce reproductive, neurologic, and developmental effects. As a consequence, several studies have been attempted to investigate the fate of PAHs in atmospheric environment during the past decades. However, there is still a lack of information in regard to the atmospheric concentration of PAHs during the "Bon Fire Night". In this study, twenty-three polycyclic aromatic hydrocarbons and twenty-eight aliphatics were identified and quantified in the $PM_{10}$ and vapour range in Birmingham ($27^{th}$ November 2001-$19^{th}$ January 2004). The measured concentrations of total particulate and vapour (P+V) PAHs were consistently higher at the BROS in both winter and summer. Arithmetic mean total (P+V) PAH concentrations were $51.04{\pm}47.62$ ng $m^{-3}$ and $22.30{\pm}19.18$ ng $m^{-3}$ at the Bristol Road Observatory Site (BROS) and Elms Road Observatory Site (EROS) respectively. In addition arithmetic mean total (P+V) B[a]P concentrations at the BROS were $0.47{\pm}0.39$ ng $m^{-3}$ which exceeded the EPAQS air quality standard of 0.25 ng $m^{-3}$. On the other hand, the arithmetic mean total (P+V) aliphatics were $81.80{\pm}69.58$ ng $m^{-3}$ and $48.00{\pm}35.38$ ng $m^{-3}$ at the BROS and EROS in that order. The lowest average of CPI and $C_{max}$ measured at the BROS supports the idea of traffic emissions being a principle source of SVOCs in an urban atmosphere. The annual trend of PAHs was investigated by using an independent t-test and oneway independent ANOVA analysis. Generally, there is no evidence of a significant decline of heavier MW PAHs from the two data sets, with only Ac, Fl, Ph, An, 2-MePh, 1+9-MePh, Fluo and B[b+j+k]F showing a statistically significant decline (p<0.05). A further attempt for statistical analysis had been conducted by dividing the data set into three groups (i.e. 2000, 2001-2002 and 2003-2004). For lighter MW compounds a significant level of decline was observed by using one-way independent ANOVA analysis. Since the annual mean of $O_3$ measured in Birmingham City Centre from 2001 to 2004 increased significantly (p<0.05), it may be possible to attribute the annul reduction of more volatile PAHs to the enhanced level of annual average $O_3$. By contrast, the heavier MW PAHs measured at the BROS did not show any significant annual reduction, implying the difficulties of 5- and 6-ring PAHs to be subject to photochemical decomposition. The deviation of SVOCs profile measured at the EROS was visually confirmed during the "Bonfire Night" festival closest to the $6^{th}$ November 2003. In this study, the atmospheric PAH concentrations were generally elevated on this day with concentrations of Fl, Ac, B[a]A, B[b+j+k]F, Ind and B[g,h,i]P being particularly high.

An Analysis of Waterfront Development Type based on Residents' Attitudes - Focused on Yeoju-Si - (지역주민 태도에 의한 수변공간 개발 형태 분석 - 여주시를 중심으로 -)

  • You, Soo-Jin;Seok, Young-Sun;Choi, Yun Eui;Chon, Jinhyung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.41 no.6
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    • pp.171-184
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    • 2013
  • The importance for local development, which residents' attitudes have reflected, is well known. Therefore, in order to formulate an approach for sustainable development, a study on sustainable waterfront development has become necessary. This study performed the first step analysis of Limits of Acceptable Change(LAC) System that considers the local residential attitude to make the analysis and standard for acceptable development type in the waterfront. This study used the characteristics of the residents, the social exchange theory, and the LAC System. This was done because it is useful to ensure that basic data can be used for the establishment of management objectives. Yeoju-Si was selected as the site for the investigation. A total of 240 surveys were obtained. Analyses were conducted to 1) determine the relationships between the residents' attitudes toward the waterfront development type and the acceptable development type and 2) to examine relationships between the residents' characteristics and the residents' attitudes toward the waterfront development. The results of this study are as follows: The development pertaining to the parameter 'nature education' arguably has the potential to generate substantial revenues for Yeoju-Si and could link the local development and conservation. This study concludes that the area of residence were closely correlated with the residents' attitudes.

Relationship between oral health quality of life and oral health-related factors in patients with successful dental implants (임플란트 완성 환자의 구강건강관련 삶의 질과 관련 요인)

  • Park, Jung-Hyun;Urm, Sang-Hwa;Kwun, Hyeon-Sook;Cho, Gab-Suk;Heo, Seung-Ju;Lee, So-Young;Yu, Byeng-Chul
    • Journal of Korean society of Dental Hygiene
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    • v.11 no.5
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    • pp.717-727
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    • 2011
  • Objectives : This study was purposed to estimate the level of oral health quality of life and the relationship between health-related factors and oral health quality of life in patients with successful dental implants. Methods : This questionnaire survey was conducted during the period from December 2009 to March 2010 with 126 patients confirmed successful dental implants in Busan. The oral health related quality of life and oral health-related factors were estimated with OHIP-14 and 8 oral health characteristics, respectively. Data analysis was performed with descriptive analysis, t-test, ANOVA, multiple regression analysis using SAS(ver 9.1) program. Results : The score of oral health quality of life in patients with successful dental implants was $12.25{\pm}7.82$. The scores of subscale of the oral health quality of life were $1.24{\pm}1.35$ in social disability, $1.60{\pm}1.37$ in handicap, $1.60{\pm}1.44$ in psychological disability, $1.70{\pm}1.38$ in functional limitation, $1.81{\pm}1.35$ in physical disability, $2.14{\pm}1.46$ in physical pain, $2.17{\pm}1.46$ in psychological discomfort, respectively. The related factors of oral health quality of life in patients with successful dental implants were absence of other type prosthesis and experience of tooth brushing education. Conclusions : The oral health related quality of life in patients with successful dental implants was relatively good condition. Social supports and chances for high quality denture and tooth brushing educations are needed to improve oral health related quality of life in patients with dental implants.

The Effect of Class Satisfaction among Students in the Department of Security Services on Career Decision Efficacy (경호학과 학생들의 전공수업만족도가 진로 결정 효능감에 미치는 영향)

  • Paek, Kyung-Hwa;Ji, Chi-Hwan
    • Korean Security Journal
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    • no.21
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    • pp.19-33
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    • 2009
  • This study attempted to investigate the effect of class satisfaction of the students majoring in the studies of security services on the efficacy of career decision. To do this, I chose 430 security services of the students majoring by the systematic stratified cluster random sampling as the subject of study. All data were analyzed the causal relationship of the collected equation. In order to do a data analysis used descriptive statistics analysis, t-test, one-way ANOVA and multiple regression analysis of SPSS. As a result, the following conclusion was drawn: First, it was found that there was not a statistically significant(learning factor, interpersonal relation, aptitude factor) difference in their major class satisfaction and career decision efficacy(goal choice, future plan, working information) according to gender. Second, it was found that there was a statistically signifiant difference in such factors as learning, interpersonal relations and aptitude, in relation to the difference in subfactor such as major class satisfaction and career decision efficacy. Third, it was found that the learning, aptitude and career factors of major class satisfaction had a statistically significant effect on the future plan. Fourth, it was found that he learning and career factors of major class satisfaction had a statistically significant effect on the resolution of the goal. Fifth, it was found that the aptitude and career factors of major class satisfaction had a statistically significant effect on job information. Sixth, it was found that the career factors of major class satisfaction had a statistically significant effect on the problem-solution. Therefore, we must first give priority to improve the class satisfaction. By doing this, we can raise the efficacy level of career decision.

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A Study on the Recognition of Students of Oriental Medical School on Cooperative System between Oriental and Western Medicine (한양방 협진에 대한 한의대생들의 인식도)

  • Yoo, Wang-Keun;Kim, Kyung-Suk
    • Journal of Society of Preventive Korean Medicine
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    • v.9 no.2
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    • pp.77-91
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    • 2005
  • The purpose of this study is to examine the recognition of the student of oriental medical school on cooperative system between Oriental and Western medicine and to provide basic information for the development of oriental medicine. In order to look at the level of recognition on cooperative system between Oriental and Western medicine, from September 1st to 15th of 2005, this study had been conducted through personal interview and questionnaires to 600 students who were attending the Department of Oriental Medicine (in both prep and regular courses) in D University, located in the City of Daegu. The data has been analyzed using statistic program, the SPSS WIN 12.0. Statistical analysis tools used for this study were frequency analysis, cross-over analysis and the t-test. The results are as follows; The students of oriental medical school had relatively high level of recognition on the basic concept, interests, necessity and potential for cooperative system between Oriental and Western medicine. However, they had negative understandings on the issue of unification of the two medical systems and it's possibility in the future. The students were optimistic about possible merits of cooperative system between Oriental and Western medicine, especially in the field of rehabilitation. On the reasons for lack of development of cooperative system between Oriental and Western medicine, the students listed prejudices existing on both sides firstly, followed by their contrasting approach on human illness, lack of legal and institutional support system, the indifferences of doctors and indifferences of oriental medical doctors. In addition, students understood that the dualism existing in our current medical system is aggravating mutual distrust between the two sides, causing the confusion of patients on the choice of medical facilities, and raising their medical bills. Therefore, in order to vitalize collaboration between Oriental and Western medicine in new health care environment, the following measures should be needed decreasing the prejudices between the two medical spheres with open mind improving educational programs in Western and Oriental medical schools; promoting joint academic research or exchange programs between the schools, and increasing government effort to minimize legal and institutional restrictions cooperative system between Oriental and Western medicine.

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A study on TPACK of mathematics teachers : Focusing on recognitions and educational needs of TPACK (수학교사의 테크놀로지 교수 내용 지식(TPACK)에 대한 연구 : TPACK에 대한 인식 및 교육요구도 분석 중심으로)

  • Lee, Da-Hee;Whang, Woo-Hyung
    • The Mathematical Education
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    • v.57 no.1
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    • pp.1-36
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    • 2018
  • The purpose of this study is to examine the relationship between utilization of technology and TPACK in mathematics teachers, and to analyze needs and retentions, difference between needs and retentions, and educational needs of TPACK in mathematics teachers. Furthermore, we will prioritize TPACK items that mathematics teachers want to change, and provide implications for teacher education related to TPACK in the future. To do this, we analyzed 328 mathematics teachers nationwide by using survey on the utilization of technology, averages of TPACK's needs and retentions, t-test of two averages, Borich's educational needs analysis, and the Locus for Focus model. The results are as follows. Firstly, the actual utilization rate was lower than the positive recognition of utilization of technology by mathematics teachers, and many mathematics teachers mentioned the lack of knowledge related to TPACK. Secondly, the characteristics of in-service mathematics teacher's needs and retentions for TPACK were clear, and TPACK's starting line of in-service mathematics teacher can be different from pre-mathematics teacher's. The retentions was high in the order of CK, PCK and PK, and the needs was higher in the order of TPACK, TCK, TK and TPK. All of the higher retentions were knowledge related to PCK, and the value of CK was extremely high among them. In addition, mathematics teachers recognized needs for integrated knowledge related to technology, and they needed more TCK than TPK. The difference between needs and retentions showed that all items except two items in the PK were significant. Retentions of all items in CK was higher than needs, needs of all items in TK, TCK, TPK and TPACK was higher than retentions, PK and PCK were mixed. Thirdly, based on the analysis of Borich's educational needs and the Locus for Focus model, teacher education on TPACK for mathematics teachers needs to focus on TPACK, TK, TCK, and TPK. Specifically, TPACK needs to combine technology in terms of creativity-convergence, mathematical connections, communication, improvement of evaluation quality, and TK needs to new technology acquisition, function of utilizing technology, troubleshoot problems with technology, TCK needs to mathematical value(esthetic, practical) with technology, and TPK needs to consider technology in terms of evaluation methods, teaching and learning methods, improvement of pedagogy. Therefore, when determining the direction of teacher education related to TPACK in the future, if they try to reflect these items in detail, the teachers could participate more actively and receive practical help.

A Study on Stochastic Estimation of Monthly Runoff by Multiple Regression Analysis (다중회귀분석에 의한 하천 월 유출량의 추계학적 추정에 관한 연구)

  • 김태철;정하우
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.22 no.3
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    • pp.75-87
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    • 1980
  • Most hydro]ogic phenomena are the complex and organic products of multiple causations like climatic and hydro-geological factors. A certain significant correlation on the run-off in river basin would be expected and foreseen in advance, and the effect of each these causual and associated factors (independant variables; present-month rainfall, previous-month run-off, evapotranspiration and relative humidity etc.) upon present-month run-off(dependent variable) may be determined by multiple regression analysis. Functions between independant and dependant variables should be treated repeatedly until satisfactory and optimal combination of independant variables can be obtained. Reliability of the estimated function should be tested according to the result of statistical criterion such as analysis of variance, coefficient of determination and significance-test of regression coefficients before first estimated multiple regression model in historical sequence is determined. But some error between observed and estimated run-off is still there. The error arises because the model used is an inadequate description of the system and because the data constituting the record represent only a sample from a population of monthly discharge observation, so that estimates of model parameter will be subject to sampling errors. Since this error which is a deviation from multiple regression plane cannot be explained by first estimated multiple regression equation, it can be considered as a random error governed by law of chance in nature. This unexplained variance by multiple regression equation can be solved by stochastic approach, that is, random error can be stochastically simulated by multiplying random normal variate to standard error of estimate. Finally hybrid model on estimation of monthly run-off in nonhistorical sequence can be determined by combining the determistic component of multiple regression equation and the stochastic component of random errors. Monthly run-off in Naju station in Yong-San river basin is estimated by multiple regression model and hybrid model. And some comparisons between observed and estimated run-off and between multiple regression model and already-existing estimation methods such as Gajiyama formula, tank model and Thomas-Fiering model are done. The results are as follows. (1) The optimal function to estimate monthly run-off in historical sequence is multiple linear regression equation in overall-month unit, that is; Qn=0.788Pn+0.130Qn-1-0.273En-0.1 About 85% of total variance of monthly runoff can be explained by multiple linear regression equation and its coefficient of determination (R2) is 0.843. This means we can estimate monthly runoff in historical sequence highly significantly with short data of observation by above mentioned equation. (2) The optimal function to estimate monthly runoff in nonhistorical sequence is hybrid model combined with multiple linear regression equation in overall-month unit and stochastic component, that is; Qn=0. 788Pn+0. l30Qn-1-0. 273En-0. 10+Sy.t The rest 15% of unexplained variance of monthly runoff can be explained by addition of stochastic process and a bit more reliable results of statistical characteristics of monthly runoff in non-historical sequence are derived. This estimated monthly runoff in non-historical sequence shows up the extraordinary value (maximum, minimum value) which is not appeared in the observed runoff as a random component. (3) "Frequency best fit coefficient" (R2f) of multiple linear regression equation is 0.847 which is the same value as Gaijyama's one. This implies that multiple linear regression equation and Gajiyama formula are theoretically rather reasonable functions.

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Knowledge and attitude change towards radiation protection after radiation safety management education in dental hygiene students (치위생과 학생들의 학업관련 특성에 따른 방사선안전관리 교육 후 방사선 방어에 대한 지식과 태도의 변화)

  • Kim, Sung-Ae;Lee, Ji-Young;Hwang, Se-Hyun;Cho, Mi-Suk;Park, Jung-Hyun;Jung, Nam-Yeong;Yu, Byeng-Chul
    • Journal of Korean society of Dental Hygiene
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    • v.15 no.1
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    • pp.101-109
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    • 2015
  • Objectives: The purpose of the study is to investigate the knowledge and attitude towards radiation protection after radiation safety management education in dental hygiene students. Methods: After receiving informed consents, a self-reported questionnaire was carried out for 135 dental hygiene students in Busan on June 17 for preliminary survey and September 3 for post-education survey, 2011. The questionnaire was modified from Han and consisted of 5 questions of general characteristics, 6 questions of radiation use, 7 questions of scholastic characteristics, 15 questions of knowledge towards radiation safety management, and 15 questions of attitude towards radiation safety management. Cronbach's alpha was 0.808 in the knowledge towards radiation safety management. Attitude towards radiation safety management included 15 questions of general attitude towards radiation safety management, individual and patient, and attitude toward radiation exposure reduction measured by Likert 5 scale. Cronbach's alpha was 0.970 in the attitude towards radiation safety management. Data were analyzed using SAS version 9.2 for educational analysis, technical analysis and multivariate analysis, paired t-test, and GLM. Results: Significant differences were shown in the knowledge and attitudes towards radiation safety management; the level of knowledge was respectively $9.8{\pm}3.0$ and $12.9{\pm}1.9$ points before and after education, and the level of attitude was $4.28{\pm}0.51$ and $4.53{\pm}0.47$ before and after the education. The levels of knowledge and attitude according to general characteristics showed a significant differences in grade and academic results. Post-education survey suggested that the education is very important and necessary and can change the knowledge and attitude towards radiation safety management in the dental hygiene students. Conclusions: Through the radiation safety management education, the levels of knowledge and attitude towards radiation safety management have changed significantly, which showed that the radiation safety management education proved to be very effective. Therefore, an effective radiation safety management education program is necessary to improve the levels of knowledge and attitude towards radiation safety management in the dental hygiene students.

The Effect of Triamcinolone Injection on the Vocal cord during Laryngeal Microsurgery in the Patient of the Vocal Polyp (성대용종환자에서 후두미세수술시에 수술부위에 Triamcinolone 국소주입이 음성에 미치는 영향에 대한 연구)

  • Yoo, Jun;Oh, Kyung Ho;Yoon, Hee Chul;Lee, Doh Young;Woo, Jeung soo;Baek, Seung Kuk;Jung, Kwang Yoon;Kwon, Soon Young
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.26 no.2
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    • pp.122-126
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    • 2015
  • Background and Objective : Laryngeal microscopic surgery (LMS) is popular method to treat for vocal polyp. There is not always the improvement of the voice after operation. Many methods have been developed for better outcome of the surgery. The purpose of this study is to investigate the effect of the triamcinolone injection at vocal cord during LMS. Materials and Methods : The medical records of 28 patients, received LMS under diagnosis of vocal polyp, were retrospectively reviewed. The patients were divided into two groups depending on whether triamcinolone injected or not (case group : Triamcinolone-injected group, control group : Triamcinolone-not injected group). The quality of voice was evaluated by GRBAS scale, fundamental frequency (Fo), jitter, shimmer and NHR (Noise to harmonic ratio) at previous operation, 4 weeks after operation, 8 weeks after operation. Each voice analysis factor was compared between case group and control group by Independent t-test. Results : The mean differences of each voice analysis factor. The mean difference of Jitter, Shimmer, NHR in case group were lower than in control group, and mean difference of GRBAS scale in case group were higher than in control group. These differences were not significant (p>0.05). Conclusion : Though there was a tendency of better voice outcome in patients of triamcinolone-injection, it may not be concluded that the triamcinolone injection is helpful for better voice outcome in surgery of vocal polyp due to statistical insignificance.

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AGAR-ALGINATE COMBINED IMPRESSION TECHNIQUE AND DIMENSIONAL CHANGE RESULTING FROM IDOPHOR DISINFECTION (아기-알지네이트 연합 인상체의 보관방법 및 idophor 침적소독에 의한 체적 변화에 관한 연구)

  • Oh Nam-Sik;Seo Joung-Min;Kim Sun-Hee;Youn Young-Ah;Shim Joon-Sung
    • The Journal of Korean Academy of Prosthodontics
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    • v.42 no.1
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    • pp.21-29
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    • 2004
  • Statement of problem : Because dental impression can be a cross-infection source, disinfection, such as immersion disinfection is nessecary. However, the disinfection process may change the volume of the impression cast. Purpose : The purpose of this study is to find out the effects on dimensional change of different storage times and methods, of agar-alginate impression when immersed in a 5% idophor disinfectant. Material and Methods : An agar-alginate impression was made from a mandible model and then was disinfected and stored according the experimental conditions and a stone model was produced. Measurements were taken between reference points on the original mandible model and they were compared to measurements taken between reference points on the stone model. The study was divided into 4 groups. In group 1, the impression was stored in a 100% humidor for 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 12 hours and 24 hours and stone models were made at each time. In group 2, the impression was immersed in 5% idophor disinfectant and then stored in a 100% humidor for the same length of times as group 1, and stone models were made at each time. In group 3, the impression was stored in extend-A-pourR, a special storage solution for 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 12 hours, 24 hours 3 days, and 7 days and stone models were made at each time. In group 4, the impression was immersed in 5% idophor disinfectant and then stored in stored in extend-A-pourR, a special storage solution for the same length of times as group 3, and stone models were made at each time. 5 impressions and stone models were made at each time to make a total of 180. The Student-t test (P < .05) was used to do a statistical analysis of the measurements of the mandible model and stone models. The repeated-measure 2-way analysis of variance (P < .05) was used to do a statistical analysis of the difference in the 4 groups. Results : The percent liner dimensional change was from $0.25{\pm}0.03%$ (group 1, 30 minutes) to $0.34{\pm}0.06%$ (group 4, 7 days). No significant change was noticed between the 4 groups. Conclusion : According to the above study, in both methods, least dimensional change was recorded when the storage times were short and in both methods, immersion in 5% idophor disinfectant did not effect dimensional change in the agar-alginate impression.