• Toxicological Research
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• 제25권3호
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• pp.132-139
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• 2009

The toxicity test of ammonium persulfate was conducted to ensure of its potential toxic effects according to the single-dose acute oral toxicity study (OECD Guideline 423) and 90-day repeated dose sub-chronic oral toxicity study guideline (OECD Guideline 408) for establishing national chemical management system, and matching in the Globally Harmonized Classification System (GHS) category. In acute oral toxicity study, pasty stool, perineal contamination and temporary body weight decrease were observed after dosing 1st and 2nd challenge (300 mg/kg body weight). All test animals were dead within 6 hours after dosing at 3rd challenge (2000 mg/kg body weight). Therefore, the GHS class of test substance is considered class 4. In sub-chronic toxicity study, body weight changes, food consumptions, hematological, biochemical and pathological examination did not show any noticeable and significant differences between the administered (5, 20, 80 mg/kg body weight) and control (vehicle only) group animals. Based on these results, the no observed adverse effect level (NOAEL) is considered above 80 mg/kg body weight.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• 제24권4호
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• pp.425-435
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• 2014

Objectives: This study was performed in order to establish reliable and relative selection criteria for hazardous substances requiring management(HSRM) in the Occupational Safety and Health Act in Korea. Methods: To determine the relative criteria and weight of evidence for HSRM, we analyzed the difference between the selection method of priority substances in studies by KOSHA(Korea Occupational Safety and Health Agency) and the European Union Risk Ranking Method(EURAM). In addition, 597 hazardous substances with exposure limit valueswereanalyzed and the posted health hazards classification by MOEL(Ministry of Employee and Labor), MOE(Ministry of Environment), and EU CLP(Classification, Labelling and Packaging regulation) were compared based on GHS(Globally Harmonized System of classification and labelling of chemicals) criteria. The existing HSRM(167 substances) were evaluated for suitability by the proposed criteria in this study. Results: As a result of this study, the criteria and procedures for selecting HSRM in the Occupational Safety and Health Act were arranged utilizing GHS health hazard classification results, occupational disease cases and domestic use situations. Conclusions: The applicability of the proposed criteria was proved via the evaluation of existing HSRM(167 substances). Most HSRM (161 substances) were found to correspond to a significant health effect or substantial health effect. The question of whether to include the six substances that have been found to have general health effects as HSRM would be require further research.

• Tunnel and Underground Space
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• 제21권3호
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• pp.205-215
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• 2011

In this study, we analyzed physical properties of granites and their correlation with rock mass classification methods. The granite samples were obtained from field survey, in-situ borehole tests and laboratory tests for a design phase of various roads, railways and other civil engineering works in Korea. Among the measured physical properties, the results of unit weight, compressive strength, tensile strength, seismic velocity, cohesion, friction angle, elastic modulus and deformation modulus were introduced. We also correlated these properties with the compressive strength. The results of different rock classification method of RQD, RMR, and Q-system against the granites in Korea were compared with each other, and the correlation equations were proposed in a more simplified form. We also derived RMR values using the compressive strength as well as the RQD values of in-situ drilled cores, and estimated the deformation modulus of in-situ rock mass in terms of the RMR values.

• Journal of information and communication convergence engineering
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• 제1권3호
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• pp.157-162
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• 2003

We propose a learning method for improving the performance of the backpropagation algorithm. The proposed method is using a fuzzy logic system for automatic tuning of the learning rate of each weight. Instead of choosing a fixed learning rate, the fuzzy logic system is used to dynamically adjust the learning rate. The inputs of fuzzy logic system are delta and delta bar, and the output of fuzzy logic system is the learning rate. In order to verify the effectiveness of the proposed method, we performed simulations on the XOR problem, character classification, and function approximation. The results show that the proposed method considerably improves the performance compared to the general backpropagation, the backpropagation with momentum, and the Jacobs'delta-bar-delta algorithm.

• Safety and Health at Work
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• 제3권3호
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• pp.224-234
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• 2012

Objectives: This study was conducted in order to obtain information concerning the health hazards that may result from a 13 week inhalation exposure of n-pentane in Sprague-Dawley rats. Methods: This study was conducted in accordance with the Organization for Economic Co-operation and Development (OECD) guidelines for the testing of chemicals No. 413 'Subchronic inhalation toxicity: 90-day study (as revised in 2009)'. The rats were divided into 4 groups (10 male and 10 female rats in each group), and were exposed to 0, 340, 1,530, and 6,885 ppm n-pentane in each exposure chamber for 6 hour/day, 5 days/week, for 13 weeks. All of the rats were sacrificed at the end of the treatment period. During the test period, clinical signs, mortality, body weights, food consumption, ophthalmoscopy, locomotion activity, urinalysis, hematology, serum biochemistry, gross findings, organ weights, and histopathology were assessed. Results: During the period of testing, there were no treatment related effects on the clinical findings, body weight, food consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, gross findings, relative organ weight, and histopathological findings. Conclusion: The no-observable-adverse-effect level (NOAEL) of n-pentane is evaluated as being more than 6,885 ppm (20.3 mg/L) in both male and female rats. n-pentane was not a classified specific target organ toxicity in the globally harmonized classification system (GHS).

• Animal Bioscience
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• 제36권4호
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• pp.584-590
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• 2023

Objective: This research aimed to explore the changes in the observed abdominal sagging index (ASI) and reproductive performance of Roman male and female geese during the breeding period. Methods: The 339 six-month-old breeding geese (109 male; 230 female) were used in this study, in which five male and five female geese were slaughtered on a monthly basis to record the ASI. Results: The short diameter of the testes of the male goose when the female goose lays eggs and in the second, third, and fourth months was significantly wider than in the fifth months (19.0, 20.8, 21.4, and 19.6 vs 12.7 and 14.0 mm/bird; p = 0.0105). On the other hand, the testicular weight of the male goose in the second and third months after the female goose lays eggs was significantly higher than that in the second and fifth months after laying (0.33% and 0.37% vs 0.11% and 0.19%; p = 0.0212). During the exploring period, the length and weight of the fallopian tube, the weight of the ovary, the number of follicles in 2 to 3 cm, the number of follicles in 3 to 4 cm, the fallopian tube weight in the carcass weight percentage, and the ovary weight in the carcass weight percentage all demonstrated a significant curve response. Further, female ASI was positively correlated with reproductive tract length (r = 0.815; p<0.05) and egg production per female (r = 0.790; p<0.05). Conclusion: The ASI classification method is more objective and easy to distinguish. This scoring method has a high correlation with the number of eggs laid by each goose and the length of the reproductive tract, inferring that the goose observation could take advantage of ASI during egg-laying and can predict the reproductive system development during the laying period and determine when the breeding goose begins to lay eggs.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제3권2호
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• pp.178-186
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• 2003

Recently, many researchers have been interested in biometric systems such as fingerprint, handwriting, key-stroke patterns and human iris. From the viewpoint of reliability and robustness, iris recognition is the most attractive biometric system. Moreover, the iris recognition system is a comfortable biometric system, since the video image of an eye can be taken at a distance. In this paper, we discuss human iris recognition, which is based on accurate iris localization, robust feature extraction, and Neural Network classification. The iris region is accurately localized in the eye image using a multiresolution active snake model. For the feature representation, the localized iris image is decomposed using wavelet transform based on dyadic Haar wavelet. Experimental results show the usefulness of wavelet transform in comparison to conventional Gabor transform. In addition, we present a new method for setting initial weight vectors in competitive learning. The proposed initialization method yields better accuracy than the conventional method.

• Journal of the Society of Naval Architects of Korea
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• 제40권6호
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• pp.12-19
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• 2003

Corrugated bulkheads for a bulk carrier are divided into watertight bulkheads and deep tank bulkheads. Design of the watertight bulkheads is principally determined by the permissible limit of Classification and IACS requirements. But, the verification of strength through finite element analysis is indispensable for design of the deep tank bulkheads. A stage for stress evaluation of corrugated part is required for optimum structural design of the deep tank bulkheads. Since the finite element analysis for real model requires excessive amount of calculation time, in this study one corrugated structure is replaced with beam element and is idealized as 2 dimensional frame structure connected to upper and lower stool Minimum weight design of the deep tank bulkheads is performed through generalized sloped deflection method(GSDM) as direct calculation method. The purpose of this study is the development of design system for the minimization of steel weight of deep tank bulkheads as well as watertight bulkheads. Discrete variables are used as design variables for the practical design. Evolution strategies(ES) is used as an optimization technique.

• Proceedings of the IEEK Conference
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.693-698
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• 2001

This paper establishes a coding method system including the liberation and size distribution of recycling materials in the shredder operation. Every particle in the shredded product becomes a code number using the liberation model and size distribution equation transforming of weight percentage into particles number percentage. One set of database can be obtained after all particles have been coded. This database is suitable for the size reduction operation in the process simulation of waste recycling. Coupling with the developed air classification, sizing and separating operations, the whole process simulation will be completely established for diversified application. A typical simulation for the rolling cutting shredder product of waste TV had been demonstrated under this coding system. The breakage size distribution of Gaudin and Schumann equation were selected for the shredding operation simulation. The Gaudin's liberation model was suitable fur the liberation simulation. Both of these equations were transformed weight percentage into particles distribution for the necessary of particle coding method. A better recycling operation for this shredded solid waste can be concluded from the comparison of simulation results with their sorted grade, recovery or economic of materials in different processes.

• Journal of Ecology and Environment
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• 제38권4호
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• pp.477-483
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• 2015

Characteristics of snake reproductive organs that are relatively less affected by external environmental conditions can be used as an important means of classification; additionally, such characteristics can provide useful information on a species' reproductive system. In this study, we compared the testis weights, hemipenis lengths and retractor muscle lengths of male Oocatochus rufodorsatus and Rhabdophis tigrinus in Colubridae and Gloydius saxatilis, G. brevicaudus and G. ussuriensis in Viperidae. The snake snout-vent lengths (SVLs) were positively related to the three reproductive organ sizes, but the body weight only exhibited a positive relationship with the testis weight. The three organs did not significantly differ on the left and right sides. The relative testis weights and retractor muscle lengths (divided by the body weight and SVL, respectively) of the Colubridae snakes were greater than for the Viperidae snakes, but the relative hemipenis lengths (divided by SVL) did not differ between the two groups. The relative testis weight of G. saxatilis and the relative retractor muscle lengths of the Viperidae snakes were smaller compared with the Colubridae snakes. The relative hemipenis length of O. rufodorsatus was greater than for R. tigrinus, G. saxatilis and G. brevicaudus. Additional comparisons were not significant. Our results may facilitate further studies on hemipenial morphology and mating competition in Korean snakes. This is the first study on Korean snake reproductive organs.