• Korean Journal of Materials Research
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• v.29 no.9
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• pp.532-541
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• 2019

Information and communication technologies are developing rapidly as IC chip size becomes smaller and information processing becomes faster. With this development, digital circuit technology is being widely applied to mobile phones, wireless LANs, mobile terminals, and digital communications, in which high frequency range of GHz is used. In high-density electronic circuits, issues of noise and EMC(Electro-Magnetic Compatibility) arising from cross talk between interconnects or devices should be solved. In this study, sheet-type electromagnetic wave absorbers that cause electromagnetic wave attenuation are fabricated using composites based on soft magnetic metal powder and silicon rubber to solve the problem of electromagnetic waves generated in wireless communication products operating at the frequency range of 2.4 GHz. Sendust(Fe-Si-Al) and carbonyl iron(Fe-C) were used as soft magnetic metals, and their concentrations and sheet thicknesses were varied. Using soft magnetic metal powder, a sheet is fabricated to exhibit maximum electromagnetic attenuation in the target frequency band, and a value of 34.2dB(99.9 % absorption) is achieved at the target frequency.

• Journal of The Korean Society of Agricultural Engineers
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• v.66 no.2
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• pp.1-12
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• 2024

In order to integrate two consolidation theories of Terzaghi's consolidation theory and Mesri's secondary compression theory and to identify a model suitable for analyzing stress-strain behavior over time, numerical analysis on consolidation tests were conducted using a modified cam-clay model and a soft soil creep model and the following conclusions were obtained. The results of numerical analysis applying the theory that a linear proportional relationship is established between the void ratio at logarithmic scale and the permeability coefficient at logarithmic scale is better agreement with the result of oedometer test than the results of applying constant hydraulic conductivity. The modified cam-clay model is a model that does not include secondary compression, but the slope of the normal consolidation line corresponding to the compression index of the standard consolidation test includes secondary compression, so the actual settlement curve over time is lower than the predicted value through numerical analysis. It always gets smaller. Other previous studies that applied Terzaghi's consolidation theory to consolidation test analysis showed the same results and were cross-confirmed. The soft soil creep model, which includes secondary compression in the theory, showed good agreement in all sections including secondary compression in the consolidation test results. It was judged appropriate to use a soft soil creep model when performing numerical analysis of soft clay ground.

• The Journal of the Korean bone and joint tumor society
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• v.1 no.2
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• pp.210-219
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• 1995

Many different factors which may affect the prognosis of the soft tissue sarcomas have been reported by many authors ; Generally, tumor size, histologic type, surgical margin, and multi modality therapy therapy as the prognostic factors were reported. The objectives of this retrospective study of soft tissue sarcomas are : 1) to define more clearly prognostic variables that have significant predictive value for disease-free and overall survival ; and 2) to evaluate tumor histologic grade based upon extent of tumor necrosis as a means of stratifying more aggressive soft tissue sarcomas(grade II & III) of the extremities. We treated 94 patients who had soft tissue sarcoma of the extremities and trunk from May 1984 to September 1994(average duration of follow-up was 5 years ranging from 2 months to 10 years) and evaluated the prognostic factors of the soft tissue sarcomas; age, sex, depth, size, location, histologic type and grade, stage, therapy modality, surgical margin, local recurrence and distant metastasis. The results were as follows. 1. The patients with poorer prognosis were over the age of fifty, whose mass was deeply located, size of the mass was over 10cm in diameter, grade III in histology, who had local recurrence, metastasis, and received only surgery. 2. Among these prognostic factors, the most significant prognostic factor was histologic grade base upon extent of tumor necrosis.

• Journal of Korean Neurosurgical Society
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• v.42 no.2
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• pp.97-102
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• 2007

Objective : The authors attempted to evaluate the pattern of the airway narrowing due to prevertebral soft tissue swelling after surgery of the anterior cervical spine and their clinical significances using plain cervical X-ray images. Methods : Twenty-four patients undergoing anterior cervical spine surgery were reviewed from January 2004 to December 2005. Postoperatively, in daily basis, lateral radiograph of the neck was obtained in neutral position. We measured the upper airway diameter above and below the epiglottis level and prevertebral soft tissue diameter every day for a week and finally 2 weeks after surgery using their simple lateral cervical X-ray films. Results : Both airway narrowing and prevertebral soft tissue swelling were maximum in postoperative 2 days, and decreased rapidly in postoperative 7 days. Airway narrowing was aggravated postoperatively but slowly decreased as prevertebral soft tissue swelling diminished. But, the severity of airway narrowing showed no clinical correlations with clinical symptom and radiologic severity. Conclusion : Not all patients who show severe airway narrowing and prevertebral soft tissue swelling on their plain cervical X-ray film complain respiratory insufficiency. But, the patients with undergoing anterior cervical spine surgery should be monitored carefully for respiratory insufficiency, especially during several days following operation because both airway narrowing and prevertebral soft tissue swelling become peak at postoperative 2-3 days.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.1
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• pp.35-41
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• 2006

It is well known that concentration of C-reactive protein(CRP) in the serum increase as nonspecific reaction of the various tissue injury. The CRP, synthesized in the hepatocyte, is one of 'acute phase proteins' in the serum. The main signal patterns of this protein are regulated by synthesis of interleukin-I secreted from macrophage in the area of tissue injury. Many studies were performed for quantitative analysis for CRP according to various surgical operation, but the study for fracture patients associated with trauma, especially in mandible, are rare. The mandible fracture have intrinsic danger for infection in oral bacteria associated with open wound in oral cavity, and, are difficult for detection of tissue reaction between surgical swelling and infection by facial swelling. In this study, quantitative analysis for CRP associated tissue injury in mandibular fracture and surgical intervention was done, the results were as follows: 1. After initial mandibular trauma, the value of serum CRP diminished sequentially, most high value was presented in post-traumatic 2 days. 2. The CRP was diminished significantly 2 days after surgical intervention, and maintained normal value in 5 days after surgery. 3. The change of CRP are higher value in surgical intervention than initial trauma, it suggested that tissue injury from surgery was severe than trauma. 4. The high value of CRP was obtained in mandibular fracture combined soft tissue injury than no associated soft tissue injury. 5. In measurement of CRP according to surgical approach, highest serum value in patients of combined intra-oral and extra-oral approach was showed, and intra-oral approach, extra-oral approach, in sequential orders. 6. The CRP value are more higher in patient of 2 fracture site than only one fracture site. From the results obtained in this study, CRP has showed different values in mandibular fracture associated with severity of tissue injury and surgical intervention, and quantitative analysis of CRP value in serum can be applied to the clinical management of mandibular fracture.

• Proceedings of the Korean Geotechical Society Conference
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• 1997.10a
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• pp.261-266
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• 1997

• International Journal of Highway Engineering
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• v.20 no.4
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• pp.21-26
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• 2018

PURPOSES : The objective of this study is to evaluate the application of soil stabilization method for soft shoulder construction in the iRoad Project of Sri Lanka. METHODS : Firstly, the quantitative analysis of soil strength improvement due to soil stabilization was done for soil samples collected from iRoad construction sites. Two types of soils were selected from iRoad Project sites and prepared for soil stabilization testing by the Road Development Authority. Secondly, the appropriate stabilizer was selected at given soil type based on test results. Two different stabilizers, ST-1 and ST-2, produced in Korea were used for estimating soil strength improvements. Finally, the optimum stabilizer content was determined for improving shoulder performance. The uniaxial compressive strength (UCS) test was conducted to evaluate the strength of stabilized soil samples in accordance with ASTM D 1633. The use of bottom ash as a stabilizer produced from power plant in Sri Lanka was also reviewed in this task. RESULTS : It is found from the UCS testing that a 3% use of soil stabilizer can improve the strength up to 2~5 times in stabilized soft shoulder soils with respect to unstabilized soils. It is also observed from UCS testing that the ST-1 shows high strength improvement in 3% of stabilizer content but the strength improvement rate with increase of stabilizer content is relatively low compared with ST-2. The ST-2 shows a low UCS value at 3% of content but the UCS values increase significantly with increase of stabilizer content. When using the ST-2 as stabilizing agent, the 5% is recommended as minimum content based on UCS testing results. Based on the testing results for bottom ash replacement, the stabilized sample with bottom ash shows the low strength value. CONCLUSIONS : This paper is intended to check the feasibility for use the soil stabilization technique for shoulder construction in Sri Lanka. The use of soil stabilizer enables to improve the durability and strength in soft shoulder materials. When applying the bottom ash as a soil stabilizer, various testings should be conducted to satisfy the specification criteria.

• Journal of Nutrition and Health
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• v.37 no.5
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• pp.394-405
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• 2004

The objective of this study is to develop a nutrition policy on food and nutrition labeling and education systems for fast food and carbonated soft drinks in Korea by identifying the fast food and soft drink use and by examining nutrition policies and labeling in Korea and other countries. Fast food is defined as food dispensed quickly at a restaurant generally offering a limited menu of inexpensive items, which may be mostly not nutritious. It is a growing component of the Korean diet, especially on children and adolescent population. Low nutrient dense beverages such as carbonated drinks are also increasing in the children and adolescent's diet in Korea and concern has been raised that these beverages may replace more nutritious beverage and provide empty calories. According to 2001 Korean national health and nutrition survey, fast food and carbonated soft drinks were most popular among 13 - 19 years old adolescents. Thirty six and 72 percent of adolescents consumed hamburger and carbonated beverage equal to or more than once a week, respectively. In United States, all processed food including soft drinks should disclose full nutrition information by nutrition labeling requirement.. Restaurant foods are not required to provide nutrition information currently, but legislation on mandatory nutrition labeling of fast foods with other restaurant foods has been proposed currently in US. The sales of foods of minimal nutritional value, such as soft drinks, in the nation's schools is regulated by the United States Department of Agriculture. Nutrition information about fast food in US has been provided by fast food companies, non-profit organizations, hospitals and government through internet, booklet and brochure, etc, but the information is available from only a few resources in Korea. This study suggests a nutrition policy on fast food and soft drink use which includes establishing mandatory nutrition labeling and developing nutrition education materials and programs by web-site, booklet and government and school programs in Korea.

• Journal of the Korean Geotechnical Society
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• v.23 no.5
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• pp.153-162
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• 2007

For the reinforced earth wall constructed on a soft ground in parallel with replacing soft soils, the behavior of the wall according to variations of thickness and stiffness of soft layer, replacement depth, and wall height is investigated using a finite element method, in which incremental construction steps including consolidation of soft soil layer are considered. The behavior of wall is characterized by investigating displacements and settlements developing at the wall, and shear strains developing in a soil deposit. The stability of wall is, then, evaluated by comparing these values with the safety criteria determined on the basis of the literature. Based on the investigation, it is shown that the behavior of wall is influenced naturally from soft soil thickness(t), replacement depth(d) and wall height(h), but more significantly from d and h. In addition, it is also shown that the normalized replacement depth, d/h, required for the safety of wall is not influenced significantly by the variations of t and h. Consequently, it can be concluded that the proper replacement depth can be suggested in an equivalent value in terms of d/h, even for the cases where the wall height is varying with stations, but the variation is not significant.

• The Journal of the Korean bone and joint tumor society
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• v.2 no.1
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• pp.33-37
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• 1996

From January 1994 to August 1995 we performed 270 cases of fine needle aspiration cytology for bone and soft tissue lesions. Among them 137 cases were diagnosed histologically. Sixty-seven cases were benign and 70 cases were malignant. We analysed these on the aspect of sensitivity, specifity, positive predictive value, negative predictive value of the cytologic examination. Malignant cases consisted of bone tumor 29 cases; soft tissue tumor 25 cases; and metastatic tumor 16 cases. The sensitivity and specifity of the aspiration cytology for malignant tumor were 67.8% and 97%, respectively. The positive and negative predictive value of aspiration cytology were 97.4% and 72.7%, respectively. Among them 40 cases were primary bony lesions; 14 benign lesions, 26 malignamt bone tumors. Sensitivity of aspiration cytology for these primary bony lesion was 90%(18/20) and its specifity was 100%(13/13). Three cases showed atypical cells in cytology but with biopsy we could find them as one benign and two malignancies. Two cases of manignancy showed negative result in cytology; one was parosteal sarcoma of proximal femur and the other was osteosarcoma of proximal tibia which was biopsied already at other hospital. Although the overall sensitivity and specifity for malignant bone and soft tissue tumors were relatively low and not so predictable, the fine needle aspiration cytology for primary bony lesion was useful in the differential diagnosis of benign or malignancy.