• Journal of Aerospace System Engineering
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• v.15 no.6
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• pp.19-25
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• 2021

This paper presents a method that uses the stress failure criteria to predict the tensile failure strength of open-hole laminates with stress concentrations. The composite material used in this study corresponds to a 177 ℃ cured, carbon/epoxy unidirectional tape prepreg. The results obtained by testing ten different laminates were compared and analyzed to verify the tensile strength of the open-hole laminates predicted using the proposed stress failure criteria. The findings of this study confirm that the tensile strength predictions performed using the proposed method are generally accurate, except in cases involving highly soft laminates (10% of 0° ply).

• Journal of Nutrition and Health
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• v.32 no.8
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• pp.887-896
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• 1999

The purpose of this research is to assess hematological and biochemical status and the prevalence of iron deficiency of pregnant women by gestational age to provide the primary data about iron nutritional status of pregnant women. Pregnant women visiting public health centers in Ulsan participated in study and were divided into 3 trimester by last menstrual period(LMP). Hemoglobin (Hgb), hematocrit(Hct)and mean corpuscular volume(MCV) among iron status indices were not statistically different from normal distribution, however total iron binding capacity(TIBC) and serum ferritin were skewed to left and serum iron and transferrin saturation(TS) were skewed to right. Hgb was positively correlated with Hct(r=0.93, p<0.001) but TIBC was negatively correlated with all indices. Serum ferritin was also correlated with all indices, especially in 3rd trimester but not reached to 1st trimester level. Mean corpuscular hemoglobin(MCH), mean corpuscular hemoglobin concentration(MCHC), Red cell distribution width(RDW), serum iron and TS were not significantly different by trimester, however when serum serum iron was adjusted with hematocrit to correct the hemodilution, it significantly decreased in 2nd trimester. MCV increased in 2nd trimester and was maintained until late pregnancy, TIBC continued to increase throughout the trimester. The prevalence of anemic by CDC(Centers for Disease Control) Hgb criteria(Hgb <11.0g/dl in 1st and 3nd trimester, Hgb<10.5g/dl in 2nd trimester) was 2.8% in 1st trimester, 22.5% in 2nd trimester, 27.1% in 3rd trimester and was similar with prevalence by CDC Hct criteria(Hct < 33% in 1st and 3rd, Hct < 32% in 2nd). The prevalence of anemic of total subjects was 32.7% by WHO criteria(Hgb < 11.0g/dl). Although almost iron status indices increased in 3rd trimester, the prevalence of anemia by different criteria of all indices increased throughout the trimester, so iron nutritional status was considered as serious during late pregnancy. However, since factors other than iron deficiency, such as infection, infection, inflammation, other nutrient deficiency may also play a significant role, to differentiate the anemia due to mainly iron deficiency from the anemia due to other factors, serum ferritin is among the more useful indices in distinguishing the two conditions because it is depressed only in iron deficiency. Hgb<11.0g/dl and serum ferritin<12.0ug/L as the criteria of iron deficiency was suggested by CDC. 17.8% of all subjects were classified as iron deficient anemia, 14.9% as anemic from other reasons, 21.2% as iron deficiency any only 46.2% were in normal iron status.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2007.10a
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• pp.19-36
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• 2007

When the trains runs at a high speed in the tunnel, passengers feel a pain in the ear that fast pressure fluctuation inside the tunnel being delivered with pressure fluctuation inside the passenger car. These phenomena are called "aural discomfort". Aural discomfort increase the passengers' uncomfort so that it is decreased a service level and serious case, it is able to damage the ear of the passenger. therefore aural discomfort must be considered the high-speed railroad tunnel cross-section design. To solve the problem of aural discomfort in a railway tunnel, some countries have standards on aural discomfort. It has been studied that different countries have different standards on aural discomfort. For that reason, the criteria of aural discomfort was reviewed through the standards of Kyungbu HSR line and different countries in this paper. And then Numerical Analysis of the Characteristics with tunnel cross-section change has been used for the selection of the optimum cross-section of Honam. The numerical analysis results were compared to field test results in order to verifying the reliability of the numerical analysis.

• Journal of Welding and Joining
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• v.20 no.3
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• pp.122-128
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• 2002

The laser welding in the automotive industries has been used widely for the butt joint of blank sheets rather than the lap joint of automotive body panels. But as a substitute far the spot welding of automotive body panels, the so called three dimensional laser welding will be important far the body panel engineers. Specially the laser welding of body panels with a smooth weld line is applied increasingly, for example, to the side panels. So far, some criteria of the laser weld quality was suggested by in-house regulations or national standards from experiences and/or rule of thumbs. In the manufacturing places, a go or no-go criterion is adopted because of the simplicity or a lack of rational criteria. It is true specially for the selection of the process parameters, which gives the basic causes for the good quality of laser welds. In this study, the effects of joint combination, gap and welding speed on the lap joint $CO_2$ laser welding of two mild steel sheets with different thicknesses are obtained through a $2{\times}3{\times}7$ factorial experiment. The results of the weld quality are statistically analysed using analysis of variance (ANOVA) and compared between two characteristic zones, which are separated by the type of sectional shapes and the level of input energy per volume. The thickness combinations are 0.8mm/1.2mm, 1.2mm/0.8mm of mild steel sheets. The welding speed covers from the deep penetration to the partial penetration. The gap size has three levels of no-gap, 0.16m, and 0.26mm. The bead width, penetration depth and input energy per volume are measured and used as the weld quality criteria.

• Journal of the Korean Society for Railway
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• v.20 no.5
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• pp.703-712
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• 2017

The railway system is an interface industry that can be safely operated by organically operating the lines, vehicles, controls, etc. Various data are generated in the operation and maintenance activities of the railway system. These data are utilized in cooperation with safety and maintenance activities in each field, but amount of data is insufficient for data analysis of safety management due to relevant data being produced without any synchronous criteria such as time or space. In particular, reference data such as location and time of failure data for each field are set to different criteria according to the work characteristics in each field. So, it is not easy to analyze data integrally based on location and time. Therefore, mapping of reference data can be required for integrated analysis of data defined in different formats. By selecting data mapping tools and verifying the results of safety relevant data with the same criteria, the purpose of this paper is to enable integrated analysis of railway safety management data occurring in different fields based on location and time.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.149-159
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• 1999

Purpose: The purpose of this study was to evaluate cervical lymph node metastasis of oral squamous cell carcinoma patients by MRI film and neural network system. Materials and Methods: The oral squamous cell carcinoma patients(21 patients. 59 lymph nodes) who have visited SNU hospital and been taken by MRI. were included in this study. Neck dissection operations were done and all of the cervical lymph nodes were confirmed with biopsy. In MR images. each lymph node were evaluated by using 6 MR imaging criteria(size. roundness. heterogeneity. rim enhancement. central necrosis, grouping) respectively. Positive predictive value. negative predictive value. and accuracy of each MR imaging criteria were calculated. At neural network system. the layers of neural network system consisted of 10 input layer units. 10 hidden layer units and 1 output layer unit. 6 MR imaging criteria previously described and 4 MR imaging criteria (site I-node level II and submandibular area. site II-other node level. shape I-oval. shape II-bean) were included for input layer units. The training files were made of 39 lymph nodes(24 metastatic lymph nodes. 10 non-metastatic lymph nodes) and the testing files were made of other 20 lymph nodes(10 metastatic lymph nodes. 10 non-metastatic lymph nodes). The neural network system was trained with training files and the output level (metastatic index) of testing files were acquired. Diagnosis was decided according to 4 different standard metastatic index-68. 78. 88. 98 respectively and positive predictive values. negative predictive values and accuracy of each standard metastatic index were calculated. Results: In the diagnosis of using single MR imaging criteria. the rim enhancement criteria had highest positive predictive value (0.95) and the size criteria had highest negative predictive value (0.77). In the diagnosis of using single MR imaging criteria. the highest accurate criteria was heterogeneity (accuracy: 0.81) and the lowest one was central necrosis (accuracy: 0.59). In the diagnosis of using neural network systems. the highest accurate standard metastatic index was 78. and that time. the accuracy was 0.90. Neural network system was more accurate than any other single MR imaging criteria in evaluating cervical lymph node metastasis. Conclusion: Neural network system has been shown to be more useful than any other single MR imaging criteria. In future. Neural network system will be powerful aiding tool in evaluating cervical node metastasis.

• The Research Journal of the Costume Culture
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• v.14 no.2
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• pp.286-298
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• 2006

The purpose of this study is to find the proper width of fabric which can bring high efficiency on productivity. We focus on the marking method by comparing and analyzing the marking efficiency of flare skirt. This study employs 4 criteria to mark the flare skirt, which are angle, location, width, and direction, respectively. There can be 3 different angles$(180^{\circ},\;270^{\circ},\;360^{\circ})$, and 2 different locations(the center line and the middle of the pattern) according to fixing of the warp line of the fabric. Also, width can be classified into 2 groups(110cm, 150cm), and marking direction can be grouped into 2(one direction marker and one direction per each size marker). These 4 criteria make $24(3{\times}2{\times}2{\times}2)$ cases for this study. Main findings are follows. Fist, the skirt with the 150cm width has higher efficiency rate than that of 110cm. Second, fixing the warp line at the center line has higher efficiency rate than that in the middle. Finally, per size marker has much higher efficiency than the just direction marker. In sum, we find that 150cm width with the center warp line and per size marker brings the highest efficiency rate.

• The Research Journal of the Costume Culture
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• v.13 no.1
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• pp.161-173
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• 2005

The Main objective of this study was to investigate the relationship between shopping orientations and Knit wear Buying Behavior of female college students in the U.S. age 18 to 33. The questionnaires for this survey were developed to measure knitwear purchasing behavior, including sources of information about knitwear, evaluative criteria of knit wear product, attributes f store preference for knitwear, and shopping orientation. The questionnaire was administered to 119 female college students in the University of California. The data was analyzed by percentage, frequency, mean, factor analysis, Cluster Analysis and ANOVA, Duncan Multiple Range test. The female college students were classified into five subdivisions by cluster analysis; cautious shopping group, recreational shopping group, self-confident shopping group, shopping indifferent group, price conscious shopping group. In the case of fashion information sources of knit wear, significant differences were found according to shopping orientation subdivision in observation of others' and famous people's clothing, fashion shows, fashion articles in magazines, newspapers, and on the Internet, and shop displays. The evaluation criteria of knit wear product were significantly different depending on shopping orientation subdivision in fashionable, brand and store name, appropriate for different occasion, prestige. The store attributes of knitwear were significantly different depending on shopping orientation subdivision in product knowledge of sales personnel, store atmosphere, display of merchandise, layaway payment plan, price level, ease of parking and access, and new fashion.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.2
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• pp.298-306
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• 2005

The Main objective of this study was to investigate the relationship between lifestyle and clothing buying behavior of college female students in Japan. A questionnaire was developed to measure clothing urchasing motives, fashion information sources, evaluation criteria of clothing, store attribute and lifestyle, The questionnaire was administered to 131 female college students in Tokyo of Japan. the data was analyzed using percentage, frequency, mean, factor analysis, Cluster Analysis and ANOVA, Duncan Multiple Range test. The results of the study were as follows : 1. The female college students were classified into fourth subdivisions by the cluster analysis; rational group, economic group, progressive group, fashion-oriented group. 2. The clothing purchasing motives o consumers were significantly different according to lifestyle subdivision in social, personal. 3. In the case of fshion information sources, significant differences were found according to lifestyle subdivision in mass media information, information by marketer, information by consumer. 4. The evaluation criteria of clothing were significantly different depending on lifestyle subdivision in esthetic, quality and management, external criterion. 5. The store attribute were significantly different depending on lifestyle subdivision in convenience, service and atmosphere of store.

• Transactions of Materials Processing
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• v.32 no.2
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• pp.92-99
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• 2023

In this study, shear fracture specimens are designed using finite element analyses for the characterization of ductile fracture criteria of metal sheets. Many recently suggested ductile fracture criteria require experimental fracture data at the shear stress states in the model parameter identification. However, it is challenging to maintain shear stress states in tension-based specimens from the initial yield to the final fracture, and the loading path can be different for the different materials even with the same shear specimen geometries. To account for this issue, two different shear fracture specimens for low ductility/high ductility metal sheets are designed using the sensitivity tests conducted by finite element simulations. Priorly mechanical properties including the Hosford-Coulomb fracture criterion of the aluminum alloy 7075-T6 and DP590 steel sheets are used in the simulations. The results show that shear stress states are well-maintained until the fracture at the fracture initiation points by optimizing the notch geometries of the shear fracture specimens.