• Title/Summary/Keyword: Effective size

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Combined Effects of Biological Control Agent Two Native Shellfish on the Hibernal Diatom Bloom of Eutrophic Water (저온기 규조 발생억제를 위한 패류의 혼합적용)

  • Lee, Song-Hee;Hwang, Soon-Jin;Kim, Baik-Ho
    • Korean Journal of Ecology and Environment
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    • v.41 no.3
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    • pp.402-411
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    • 2008
  • Grazing effects of two freshwater shellfish, Unio douglasiae (UNIO) and Cipangoplaudina chinese malleata (CCM), on the hibernal diatom communities in eutrophic water was examined in a laboratory. Two animals having different feeding types used in the study were collected from Keum River (Boryeong, Korea), acclimatized in the artificial management system in a laboratory over at least one month, and starved in a laboratory for 2 days before the experiment. Experimental waters, which dominated by Synedra ulna-Scenedesmus sp. (ca. 80%), was collected from eutrophic lake, Lake Ilgam (Seoul) in Feb., 19, 2008 at AM 10:00, and used in the study after the filtration with 1 mm Nylon mesh. Feeding experiments were largely divided into three kinds of animal treatments; five densities of UNIO (U0, U1, U2, U3, U4) and CCM (C0, C1, C2, C3, C4), and four combined densities of two shellfish (M0, M1, M2, M3). U0 and C0 were control (no addition of UNIO or CCM), U1 or C1 (each animal density at 0.5 ind. $L^{-1}$), U2 or C2 (1.0 ind. $L^{-1}$), U3 or C3 (1.5 ind. $L^{-1}$), and U4 or C4 (2.0 ind. $L^{-1}$), respectively. Four combined treatments were consisted of M0 (no animals), M1 (U1+C3), M2 (U2+C2), and M3 (U4+C1), respectively. Under the presence of animal, the concentration of Chl-a and algal abundance were clearly decreased with the increase of UNIO density and the treated time, while in combined group a strong decrease of algal density showed with the increase of UNIO density. Total phytoplankton density shifted as the similar patterns to that of Chl-a concentration (r=0.6527, p<0.0001), however, there showed the differences following a species. There were strong decreases of dominant species Synedra ulna, Scenedesmus sp., Ankistrodesmus falcatus in UNIO treatment group, Diatoma vulgare in combined group, while Cryptomonas ovata in high density of CCM increased about 20% in algal density. Grazing rates (GRs) based on the concentration of Chl-a was depend on the kind of shellfish and treatment time; a strong feeding of CCM showed in the initial stage, and four hours later, UNIO and combined group with high UNIO density showed the high GRs. Interestingly, faeces production of shellfish was highest in combined group with high density of CCM, while their size over 60 ${\mu}m$ was much higher in production magnitude than that less 60 ${\mu}m$. Collectively, these results suggest that two domestic shellfish and its combined treatment have a strong potential as an effective biological controller of diatom bloom in cold eutrophic waters.

Development of a Finger Tactile Stimulator Based on E-Prime Software (E-Prime에 기반한 손가락 촉각 자극기의 개발)

  • Kim, Hyung-Sik;Min, Yoon-Ki;Kim, Bo-Seong;Min, Byung-Chan;Yang, Jae-Woong;Lee, Su-Jeong;Choi, Mi-Hyun;Yi, Jeong-Han;Tack, Gye-Rae;Lee, Bong-Soo;Jun, Jae-Hoon;Chung, Soon-Cheol
    • Science of Emotion and Sensibility
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    • v.13 no.4
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    • pp.703-710
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    • 2010
  • In this study, a tactile stimulator was developed to resolve some problems from the previous version of the system such as system configuration, inappropriate stimulation control and additional problems. The developed tactile stimulator consists of control unit, drive unit and vibrator unit. The control unit was controlled by E-Prime software to generate appropriate vibration pulses. The drive unit supplies enough energy to the vibrator to generate effective stimulation pulses. The vibrator unit consists of small coin type vibrator and velcro, and was made to be attached at the hand easily. The developed tactile stimulator was designed by small-size, light-weight, low-power, simple-fabrication, max 35 channels and little delay time from instruction signal of E-Prime software to vibrator. The duration and magnitude of stimulation was controlled by 10 grades and the problems concerning stimulation control were compensated by wideband frequency ranges. Additionally, the electrical safety was ensured by low voltage operation. Vibrator was made to be attached on finger as well as on any part of the subject. Since this tactile stimulator is developed based on E-Prime software which is widely used in cognitive science, it is believed that this stimulator be suitable for the wide application of cognitive science study.

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Effects of Dansambohyultang on the Gastrointestinal Mucosa of Rats Stressed by Heating, Immobilization and Starvation (단삼보혈탕(丹蔘補血湯)이 Stress로 유발(誘發)된 백단삼보혈탕(白丹蔘補血湯)이 Stress로 유발(誘發)된 백서(白鼠) 위장관(胃腸管)의 조직손상(組織損傷)에 미치는 영향(影響))

  • Ryu, Bong-Ha;Park, Dong-Won;Ryu, Ki-Won;Kong, Hyun-Sig
    • The Journal of Internal Korean Medicine
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    • v.21 no.1
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    • pp.74-86
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    • 2000
  • Objectives : This is the experimental paper to study the curative and preventive effects of Dansambohyultang, Methods : Oriental herb medicine for gastro-intestinal disease caused by stress, on the rats put under the stress through starvation, heating and immoblization, the author used four different group; the normal group, which was not put under stress and well fed, and the control group, to which the drug was not administered and put under the stress through starvation, heating and immoblization, the Sample I, to which the drug was administered before they were put under stress, the Sample lI, to which the drug was administered after they were put under stress. Results : When a Masson's trichrome stain method was applied to the control group, a small size of ulcer was found in the fundus and the pylorus, and atrophy was observed in the neck region of mucous membrane. When the drug was administered to the Sample I and the Sample II, the former recovered from the ulcer and atrophy to almost normal and showed better results than the latter. When a Masson's trichrome stain method was applied to the control group, atrophy of mucous membrane was found all over the intestines. When the drug was administered to the Sample I and the Sample ll, the curative and recovered effects was seen in both, but the former showed better results than the latter. After application of Mayer's hematoxylin stain method, the observation of numerical changes of goblet cells in the small intestines showed the most significant decrease in the control group. In the Sample I, the number of the cells in the duodenum, the jejunum and the ileum returned to an almost normal level. In the Sample II, a slight increase was observed only in the ileum. After application of Mayer's hematoxylin stain method, the observation of numerical changes of goblet cell in the large intestines showed a significant decreased in the control group. Both the Sample I and the Sample II showed an increase in the number of goblet cells in comparison with the control group. When a serotonin-immunoreaction test was applied, the control group showed a general decrease in the number of gastro-entero-endocrine cells, The Sample I showed the effect in all over gastro.intestinal tract as compared with control group and the Sample II showed the effect in all over gastro-intestinal tract except the duodenum and the former showed better results than the latter. Conclusion : According to the above results, the regions which are most sensitive to stress were observed to the ileum and the colon. It was concluded that Dansambohyultang has a remedical value particularly on the abnormalities caused by stress in all over gastro-intestinal tract and it was found to be more effective in the Sample I than in the Sample ll. Judging from the fact that the Sample I showed better results than the Sample ll, Dansambohyultang can be said to have a preventive effect more than a curative effect on gastro-intestinal tract disease.

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Results of Stereotactic Radiosurgerv with Linear Accelerator for Intracranial Arteriovenous Malformation (두개강내 동정맥기형에서 선형가속기를 이용한 방사선수술의 결과)

  • Lee Kang Kyoo;Park Kyung Ran;Lee Jong Young;Lee Yong Ha
    • Radiation Oncology Journal
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    • v.15 no.3
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    • pp.215-224
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    • 1997
  • Purpose : Stereotactic radiosurgery with external beam irradiation successfully obliterates carefully selected intracranial arteriovenous malformation (AVM) . We Present clinical and radiological long term results after treatment with a single high dose irradiation using a linear accelerator. Materials and Methods : Rrom January 1991 to June 1994, fifteen patients with intracranial AVM were treated in our hospital with the stereotactic radiosurgery using a linear accelerator. The radiation was delivered using a 6 MV linear accelerator. The prescribed doses at the isocenter varied from 1800 to 2500cGy (median : 2000cGy) and were given as a sin91e fraction. The radiation doses at the periphery of the lesion typically corresponded to the 80-90% isodose line. In 14 patients, complete clinical and/or radiological follow-up examination were available. Results : Angiography was available in 13 patients with a follow-up Period from 18 months to 27 months. Of 13 patients, the overall complete obliteration rate was 92.3% (12 patients). This incidence did not correlate with lesion size. Seizure, headache and progressive neurologic deficit were complete recovered. One Patient experienced hemorrhage at 2 months after treatment. One patient developed radiation induced brain edema in the white matter surrounding nidus at 16 months after treatment and showed complete resolution of the edema in MR image obtained at 27 months after treatment. After a follow-up period of up to 6 years, no radiation induced severe late complications occurred. Conclusion : We conclude that stereotactic radiosurgery using a linear accelerator is an effective and safe therapy for symptomatic and surgically inaccessible intracranial AVMs and the results compare favorably to the more expensive and elaborate systems that are currently available for stereotactic radiosurgery.

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Comparison of Forcep-biopsy and Cryo-biopsy by a Flexible Bronchoscopy (굴곡성 기관지경을 통한 겸자 생검술과 냉동 생검술의 비교)

  • Kim, Jae Hyun;Choi, Jung Min;Song, Sung Eun;Lee, Eun Mi;Lee, Song Ju;Oak, Chul Ho;Jang, Tae Won;Jung, Man Hong;Jang, Hee Kyung
    • Tuberculosis and Respiratory Diseases
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    • v.66 no.2
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    • pp.110-115
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    • 2009
  • Background: A forceps-biopsy is performed to acquire tissue from patients with an endobronchial carcinoma using a flexible bronchoscope. Recently, a cryo-biopsy has also been used to acquire tissue samples. Cryo-biopsy is the diagnostic application of extreme cold for the local destruction of abnormal living tissue. This technique is safe, with no radiation danger, no risk of electrical accidents, and a little risk of bleeding. This study compared a forceps-biopsy with a cryo-biopsy using a flexible bronchoscope, and examined the chemosensitivity and level of VEGF (vascular endothelial growth factor) in the specimens obtained from the cryo-biopsy. Methods: We present a prospective study of 30 consecutive patients who underwent a forceps-biopsy between January 2007 and October 2007 with a mean age of 62.1 years and a male:female ratio of 5 : 1. A flexible bronchoscope was inserted to the area of the abnormal lesions, and a cryo-probe was then applied through the working channel of the flexible bronchoscope. A temperature of approximately -h80 was delivered to the tumor site for 8 seconds. The cryo-biopsy was performed after destroying the tumor mass. Results: The mean size of the tissue from the forceps-biopsy and cryo-biopsy were 2.0${\pm}$1.2 mm and 6.0${\pm}$3.0 mm. A chemosensitivity test was performed on 5 specimens obtained using cryo-biopsy and the level of VEGF was examined in 2 specimens obtained from a cryo-biopsy. There were no side effects in either group. Conclusion: Cryo-biopsy using a flexible bronchoscope is a safe and effective technique for acquiring tissue samples.

The Effects of Work-Life Balance on Corporate Performance: Mediating Effect of Product Innovation in Venture SMEs (벤처중소기업의 일과 생활의 균형이 기업성과에 미치는 영향: 제품혁신의 매개효과)

  • Bae, Hoyoung
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.10 no.4
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    • pp.49-57
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    • 2015
  • This research is to analyze the mediating effect of product innovation between work-life balance (work-family balance, work-leisure balance and work-development balance) and corporate performance in venture SMEs. We test four hypothesis. First, we test the hypothesis that work-life balance has a positive effect on product innovation. Second, we test the hypothesis that product innovation has a positive effect on corporate performance. Third, we test the hypothesis that work-life balance has a positive effect on corporate performance. Fourth, we test a positive mediating role of product innovation between work-life balance and corporate performance. For this research, we administered the questionnaire surveys, and got the 162 effective data of korean venture SMEs. We use CFA and SEM analysis of research model by AMOS 18.0. As a result, we can find the four meaningful results. First, work-life balance, especially only work-development balance, has a positive effect on product innovation. Second, product innovation has a positive effect on corporate performance. Third, the relationships between work-life balance (work-family balance, work-leisure balance and work-development balance) and corporate performance are no significant after the mediating variable (product innovation) is added. Fourth, product innovation has a positive mediating effect between work-life balance, especially only work-development balance, and corporate performance. Although this research has some limitations of generalization because of the limited size of samples, we has meaningful information related to the venture companies in the academic and business field. Additionally, the Multiple Indicator Multiple Cause(MIMIC) model is recommended in the future research.

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The Prediction of DEA based Efficiency Rating for Venture Business Using Multi-class SVM (다분류 SVM을 이용한 DEA기반 벤처기업 효율성등급 예측모형)

  • Park, Ji-Young;Hong, Tae-Ho
    • Asia pacific journal of information systems
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    • v.19 no.2
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    • pp.139-155
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    • 2009
  • For the last few decades, many studies have tried to explore and unveil venture companies' success factors and unique features in order to identify the sources of such companies' competitive advantages over their rivals. Such venture companies have shown tendency to give high returns for investors generally making the best use of information technology. For this reason, many venture companies are keen on attracting avid investors' attention. Investors generally make their investment decisions by carefully examining the evaluation criteria of the alternatives. To them, credit rating information provided by international rating agencies, such as Standard and Poor's, Moody's and Fitch is crucial source as to such pivotal concerns as companies stability, growth, and risk status. But these types of information are generated only for the companies issuing corporate bonds, not venture companies. Therefore, this study proposes a method for evaluating venture businesses by presenting our recent empirical results using financial data of Korean venture companies listed on KOSDAQ in Korea exchange. In addition, this paper used multi-class SVM for the prediction of DEA-based efficiency rating for venture businesses, which was derived from our proposed method. Our approach sheds light on ways to locate efficient companies generating high level of profits. Above all, in determining effective ways to evaluate a venture firm's efficiency, it is important to understand the major contributing factors of such efficiency. Therefore, this paper is constructed on the basis of following two ideas to classify which companies are more efficient venture companies: i) making DEA based multi-class rating for sample companies and ii) developing multi-class SVM-based efficiency prediction model for classifying all companies. First, the Data Envelopment Analysis(DEA) is a non-parametric multiple input-output efficiency technique that measures the relative efficiency of decision making units(DMUs) using a linear programming based model. It is non-parametric because it requires no assumption on the shape or parameters of the underlying production function. DEA has been already widely applied for evaluating the relative efficiency of DMUs. Recently, a number of DEA based studies have evaluated the efficiency of various types of companies, such as internet companies and venture companies. It has been also applied to corporate credit ratings. In this study we utilized DEA for sorting venture companies by efficiency based ratings. The Support Vector Machine(SVM), on the other hand, is a popular technique for solving data classification problems. In this paper, we employed SVM to classify the efficiency ratings in IT venture companies according to the results of DEA. The SVM method was first developed by Vapnik (1995). As one of many machine learning techniques, SVM is based on a statistical theory. Thus far, the method has shown good performances especially in generalizing capacity in classification tasks, resulting in numerous applications in many areas of business, SVM is basically the algorithm that finds the maximum margin hyperplane, which is the maximum separation between classes. According to this method, support vectors are the closest to the maximum margin hyperplane. If it is impossible to classify, we can use the kernel function. In the case of nonlinear class boundaries, we can transform the inputs into a high-dimensional feature space, This is the original input space and is mapped into a high-dimensional dot-product space. Many studies applied SVM to the prediction of bankruptcy, the forecast a financial time series, and the problem of estimating credit rating, In this study we employed SVM for developing data mining-based efficiency prediction model. We used the Gaussian radial function as a kernel function of SVM. In multi-class SVM, we adopted one-against-one approach between binary classification method and two all-together methods, proposed by Weston and Watkins(1999) and Crammer and Singer(2000), respectively. In this research, we used corporate information of 154 companies listed on KOSDAQ market in Korea exchange. We obtained companies' financial information of 2005 from the KIS(Korea Information Service, Inc.). Using this data, we made multi-class rating with DEA efficiency and built multi-class prediction model based data mining. Among three manners of multi-classification, the hit ratio of the Weston and Watkins method is the best in the test data set. In multi classification problems as efficiency ratings of venture business, it is very useful for investors to know the class with errors, one class difference, when it is difficult to find out the accurate class in the actual market. So we presented accuracy results within 1-class errors, and the Weston and Watkins method showed 85.7% accuracy in our test samples. We conclude that the DEA based multi-class approach in venture business generates more information than the binary classification problem, notwithstanding its efficiency level. We believe this model can help investors in decision making as it provides a reliably tool to evaluate venture companies in the financial domain. For the future research, we perceive the need to enhance such areas as the variable selection process, the parameter selection of kernel function, the generalization, and the sample size of multi-class.

The Moderating Effect of Social Capital between Organizational Slack and Managerial Practices for Open Innovation in Venture SMEs (벤처중소기업의 조직여유와 개방형 경영혁신 간의 관계에서 사회적 자본의 조절효과 연구)

  • Bae, Hoyoung
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.10 no.5
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    • pp.73-81
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    • 2015
  • This research is designed to analyze the moderating effect of social capital between organizational slack and managerial practices for open innovation. After controlling the firm size, firm age, and environmental uncertainty, we test two hypotheses. First, we test the hypothesis that organizational slack has a positive effect on managerial practices for open innovation. Especially we focus on the managerial innovation and open innovation because recently managerial innovation and open innovation are more and more important. Second, we test the moderating role of social capital between organizational slack and managerial practices for open innovation. Because social capital is a kind of networking activity, we assume that social capital can contribute to managerial practices for open innovation through the networking activity. For this research, we administered the questionnaire surveys, and got the 250 effective data (companies) in Korea. Then we used the validity, reliability, correlation and multiple regression analysis by means of SPSS 18.0. As a result, we can find the two meaningful results. First, organizational slack, especially not absorbed slack but unabsorbed slack, has positive effect on managerial practices for open innovation. It is because absorbed slack such as excessive facilities, machines, or employees is not useful in managerial practices for open innovation. On the other hand, unabsorbed slack is useful in managerial practices for open innovation because unabsorbed slack such as excessive money or securities is very flexible and active. Taken together, the relationship between managerial practices for open innovation and unabsorbed slack is proven in terms of flexibility. Second, social capital has a moderating effect positively between organizational slack, especially not absorbed slack but unabsorbed slack, and managerial practices for open innovation. A prior study related to the relationship between managerial practices for open innovation and social capital doesn't exist yet, so this analysis result is very meaningful in academic respect. But this research has some limitations. First, this research is analyzed by limited region (Korea) and samples (250 companies), so more global regions and samples are recommended in the future. Second, we focus on managerial practices for open innovation in this paper, so the studies about technological practices for open innovation are recommended in the future.

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Development of Automated Region of Interest for the Evaluation of Renal Scintigraphy : Study on the Inter-operator Variability (신장 핵의학 영상의 정량적 분석을 위한 관심영역 자동설정 기능 개발 및 사용자별 분석결과의 변화도 감소효과 분석)

  • 이형구;송주영;서태석;최보영;신경섭
    • Progress in Medical Physics
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    • v.12 no.1
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    • pp.41-50
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    • 2001
  • The quantification analysis of renal scintigraphy is strongly affected by the location, shape and size of region of interest(ROI). When ROIs are drawn manually, these ROIs are not reproducible due to the operators' subjective point of view, and may lead to inconsistent results even if the same data were analyzed. In this study, the effect of the ROI variation on the analysis of renal scintigraphy when the ROIs are drawn manually was investigated, and in order to obtain more consistent results, methods for automated ROI definition were developed and the results from the application of the developed methods were analyzed. Relative renal function, glomerular filtration rate and mean transit time were selected as clinical parameters for the analysis of the effect of ROI and the analysis tools were designed with the programming language of IDL5.2. To obtain renal scintigraphy, $^{99m}$Tc-DTPA was injected to the 11 adults of normal condition and to study the inter-operator variability, 9 researchers executed the analyses. The calculation of threshold using the gradient value of pixels and border tracing technique were used to define renal ROI and then the background ROI and aorta ROI were defined automatically considering anatomical information and pixel value. The automatic methods to define renal ROI were classified to 4 groups according to the exclusion of operator's subjectiveness. These automatic methods reduced the inter-operator variability remarkably in comparison with manual method and proved the effective tool to obtain reasonable and consistent results in analyzing the renal scintigraphy quantitatively.

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Development of Lead Free Shielding Material for Diagnostic Radiation Beams (의료영상용 방사선방호를 위한 무납차폐체 개발)

  • Choi, Tae-Jin;Oh, Young-Kee;Kim, Jin-Hee;Kim, Ok-Bae
    • Progress in Medical Physics
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    • v.21 no.2
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    • pp.232-237
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    • 2010
  • The shielding materials designed for replacement of lead equivalent materials for lighter apron than that of lead in diagnostic photon beams. The absorption characteristics of elements were applied to investigate the lead free material for design the shielding materials through the 50 kVp to 110 kVp x-ray energy in interval of 20 kVp respectively. The idea focused to the effect of K-edge absorption of variable elements excluding the lead material for weight reduction. The designed shielding materials composited of Tin 34.1%, Antimon 33.8% and Iodine 26.8% and Polyisoprene 5.3% gram weight account for 84 percent of weight of lead equivalent of 0.5 mm thickness. The size of lead-free shielder was $200{\times}200{\times}1.5\;mm^3$ and $3.2\;g/cm^3$ of density which is equivalent to 0.42 mm of Pb. The lead equivalent of 0.5 mm thickness generally used for shielding apron of diagnostic X rays which is transmitted 0.1% for 50 kVp, 0.9% for 70 kVp and 3.2% for 90 kVp and 4.8% for 110 kVp in experimental measurements. The experiment of transmittance for lead-free shielder has showed 0.3% for 50 kVp, 0.6% for 70 kVp, 2.0% for 90 kVp and 4.2% for 110 kVp within ${\pm}0.1%$. respectively. Using the attenuation coefficient of experiments for 0.5 mm Pb equivalent of lead-free materials showed 0.1%. 0.3%, 1.0% and 2.4%, respectively. Furthermore, the transmittance of lead-free shielder for scatter rays has showed the 2.4% in operation energy of 50 kVp and 5.9% in energy of 110 kVp against 2.4% and 5.1% for standard lead thickness within ${\pm}0.2%$ discrepancy, respectively. In this experiment shows the designed lead-free shielder is very effective for reduction the apron weight in diagnostic radiation fields.