• Journal of the Korea Computer Graphics Society
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• v.20 no.1
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• pp.13-19
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• 2014

In this paper, we introduce a real-time method to render a 3D scene using image-based lighting. Previous approaches for image-based lighting focused on diffuse reflection and mirror-like specular reflection. In this paper, we provide a simple preprocessing approach to efficiently approximate Phong reflection model, which has been used for computer graphics applications for several decades. For diffuse reflection, we generate a texture map for diffuse reflection by integrating the source image in preprocessing step, similarly to the previous approaches. We adopt the similar idea to produce a set of specular reflection maps for various material shininess. By doing this, we can render a dynamic scene without high computational complexity or numerous texture map access.

• Journal of Korean Neurosurgical Society
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• v.29 no.11
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• pp.1451-1455
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• 2000

Objective : The goal of this study is to present whether endoscopic release(ER) is superior to open release(OR) for the treatment of carpal tunnel syndrome(CTS). Method and Material : Fifty-nine wrists in 43 patients who had clnical signs and symptoms consistent with CTS, not responded to non-operative management, were entered into the study. Authors retrospectively compared 27 wrists treated with ER(February 1999-June 1999) with 32 wrists treated with OR(October 1997-March 1999). We performed conventional open surgery in 25 patients(mean age ; 46 years) and Brown's two-portal technique in 18 patients(mean age ; 53 years) under intravenous regional block or general anesthesia. Results : Sixteen patients had CTS on both hands and left hands were affected more frequently than right hand, 34 and 25 respectively. Successful and poor results of ER were similar to those of OR. For patients in OR group, mean duration of symptoms was 5 years(range 1 month-30 years), and postoperative outcome was good in 27(84.4%) of wrists and poor in 5(15.6%). For patients in ER group, mean duration of symptoms was 7 months (range 2 months-25 years), outcome was good in 23(85.2%) of wrists and poor in 4(14.8%). The average time for complete relief of pain was 1.3 weeks and 7.6 weeks, respectively for OR and ER groups. No complication was noted in either group. Conclusion : This preliminary analysis suggests that faster relief of pain was achieved when the endoscopic method was used, although there were no significant differences in their efficacies regarding the improvement of symptoms.

• Journal of Korean Neurosurgical Society
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• v.29 no.7
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• pp.929-934
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• 2000

Objective : The results of secondary transsphenoidal surgery(TSS) for either residual or recurring pituitary adenomas have been reported to be unfavorable. To evaluate the effectiveness of secondary TSS, we analyzed the surgical results of residual or recurred pituitary adenomas in patients who underwent secondary TSS from 1992 to 1998. Material and Methods : Among the 95 patients who underwent TSS during this period, 14(15%) received repeated TSS. Two of the 14 patients underwent three TSS. Among the 11 patients with pituitary adenomas, three had nonfunctioning tumors ; six prolachnomas ; two GH-secreting adenomas. The remaining three patieats had craniopharyngioma, pituitary abscess and hemangioendothelioma respectively. The interval between the two surgical procedures ranged from one week to 33 months(mean ; 12 months). Causes of the secondary TSS were tumor recurrence in 11 patients, intentional staged operation in three, persistent disease despite medical therapy and CSF leak after initial operation in one respectively. Treatments prior to secondary TSS were medical treatment only in eight patients. Results : During the repeated operationtss some adhesion was noted in septal mucous membrane. The sphenoid cavity was filled with fibrous tissue which correlated with the methods of reconstruction of the sellar floor at the previous operation. There was no statistically significant difference in success rate of surgery between the initial and the second TSS(86% vs 81%). The complication rate was similar between the two procedures. There was no statistically significant factors affecting the results of second TSS. Conclusion : Transsphenoidal reoperation was regarded as a suitable approach for treating recurrent pituitary adenomas in spite of some degree of operative difficulties. In patients with transsphenoidally resectable tumor residuals or recurrences confirmed by magnetic resonance imaging, remissions can be obtained with high probability, especially in secondary surgery after an staged decompression.

• International Journal of Highway Engineering
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• v.18 no.4
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• pp.29-35
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• 2016

PURPOSES : The new waste management policy of South Korea encourages the recycling of waste materials. One material being recycled currently is tire-derived fuel (TDF) ash. TDF is composed of shredded scrap tires and is used as fuel in power plants and industrials plants, resulting in TDF ash, which has a chemical composition similar to that of the fly ash produced from coal. The purpose of this study was to evaluate the properties of an asphalt concrete mix that used TDF ash as the mineral filler. METHODS : The properties of the asphalt concrete were evaluated for different mineral filler types and contents using various measurement techniques. The fundamental physical properties of the asphalt concrete specimens such as their gradation and antistripping characteristics were measured in accordance with the KS F 3501 standard. The Marshall stability test was performed to measure the maximum load that could be supported by the specimens. The wheel tracking test was used to evaluate the rutting resistance. To investigate the moisture susceptibility of the specimens, dynamic immersion and tensile strength ratio (TSR) measurements were performed. RESULTS : The test results showed that the asphalt concrete containing TDF ash satisfied all the criteria listed in the Guide for Production and Construction of Asphalt Mixtures (Ministry of Land, Infrastructure and Transport, South Korea). In addition, TDF ash exhibited better performance than that of portland cement. The Marshall stability of the asphalt concrete with TDF ash was higher than 7500 N. Further, its dynamic stability was also higher than that listed in the guide. The results of the dynamic water immersion and the TSR showed that TDF ash shows better moisture resistance than does portland cement. CONCLUSIONS : TDF ash can be effectively recycled by being used as a mineral filler in asphalt, as it exhibits desirable physical properties. The optimal TDF ash content in asphalt concrete based on this study was determined to be 5%. In future works, the research team will compare the characteristics of asphalt concrete as function of the mineral filler types.

• BMB Reports
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• v.30 no.1
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• pp.1-6
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• 1997

The ability of Hep-G2 cells to process $[^{125}I]LDL$ under basal conditions was investigated. The receptor-binding and internalization of $[^{125}I]LDL$ increased with the time of incubation in a saturable manner. After 4 h of incubation, 31.4 ng of $[^{125}I]LDL$ was cell bound. The cells rapidly internalized $[^{125}I]LDL$ via specific, receptor-mediated endocytosis. The amount of internalized $[^{125}I]LDL$ reached a maximun of 96.7 ng at 2 h of incubation and remained constant for the next 2 h. The rate of degradation of internalized $[^{125}I]LDL$ proceeded in a linear manner over the entire 4 h of incubation after an initial lag period. The effects of individial fatty acids (C18:0. C18:1, C18:2. and C18:3), differing in their degree of unsaturation. on the receptor-binding, internalization and degradation of $[^{125}I]LDL$ were also investigated. Inclusion of 1.0 mM of each fatty acid into the culture medium significantly increased $[^{125}I]LDL$ metabolism in Hep-G2 cells. Among the fatty acids tested, stearic acid had the least effect on the receptor-binding activity. There were no significant differences among the unsaturated fatty acids in LDL-receptor binding. The effect of individual fatty acids on the $[^{125}I]LDL$ uptake was similar to that of the receptor-binding. showing a significantly lower effect with stearic acid. The amount of degraded material of internalized $[^{125}I]LDL$ was the lowest with stearic acid when it was compared with unsaturated fatty acids.

• Journal of the Korean Society of Costume
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• v.55 no.3 s.93
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• pp.59-68
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• 2005

The purpose of this study is to examine the changing process of hairstyle and the fashion trend of hairstyle in the environment where it is possible to change one's hairstyle easily arid .display oneself in various ways and the interest in hairstyle is increasing. To examine the change of real university girls' hairstyle, I selected commencement pictures of Chungnam University as material. As a method of analysis, I compared and anaylized each time period's fashion trend and the change of real university girls' hairstyle after abstracting formative element of hairstyle on the basis of preceding studies on hairstyle and measuring frequency by element of each time period. Analyzing university girls' pictures showed that many of them had curls when various perms appeared and majority of them had straight style when straight perm and magic iron appeared. When products of hairstyling were on the market and globalization changed sense of beauty, it was highly popular to set up forelock with hairstyling products. In a pluralistic social environment, desire for color aspect other than formative aspect increased. As various hairdyes were developed, hairdyeing was generalized and university girls came to accept it as natural. Fashion trend of each time period and university girls' hairstyle showed generally similar trend. In mid 1980s, curl was popular, and, in late 1980s, straight style and setting up forelock with hairstyling products were on the increase. In early 1990s, the emergence of coating perm which combined perm and hairdyeing increased hairdyeing. In late 1990s, straight style was popular and layers expressed naturalness. In early 2000s, university girls showed off their long hair in various ways and hairdyeing drastically increased.

• International Journal of Costume and Fashion
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• v.5 no.1
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• pp.14-25
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• 2005

The objective of this study is to understand bodily extension and identity in contemporary fashion art through the analysis of 'the fashion acting on the body' among the fashion theory excluding body and the conspicuous works on the opening and covering images as a fashion art as a body-space'. This study also investigated identity problems where there are poles apart in opening and closure their bodies and body-space in which its clothing types were distorted by being de-bodilization out of the traditional and ideological expression method in contemporary fashion art from a opening and closure point of view. Image of opening and closure among body-space in fashion art can be classified into opposing structure of opening and closure. Destroying the boundary between bodily opening and closure for a primary function of clothing and dismantling the role and boundary between body and clothing, opening body-space in appearance as a reemergence of body image or the border between inner and outer are being ambiguous because of transparent material. Being representative work of this study opening body-space was expressed as an opening space image using transparency. On the contrary, closure body-space was isolated from external environment and confined in the certain space, which could limit or restraint body- action. Excluding boundary of body and clothing on the whole or in part, boundary of work becomes body-space. However, these were appeared to be a work inducing unlimited curiosity and meaning from the audience. The interpretation of artistic and body-space in fashion art are indicating the role and function of the fashion art exceeding the suggestible dimensions in the every day life of fashion. The body-space of fashion art showing similar aspect of body art today could be understood that it is substituted into an metaphorical, critical space by seeing it as a symbol system connected with social space. Therefore, contemporary fashion art should be interpreted as an equivocal space looking at the body-space with open mind.

• Transactions on Electrical and Electronic Materials
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• v.14 no.3
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• pp.160-163
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• 2013

We investigated the effect of light intensity and wavelength of a solar cell device by using photoconductive atomic force microscopy (PC-AFM). The $POCl_3$ diffusion doping process was used to produce a p-n junction solar cell device based on a Poly-Si wafer and the electrical properties of prepared solar cells were measured using a solar cell simulator system. The measured open circuit voltage ($V_{oc}$) is 0.59 V and the short circuit current ($I_{sc}$) is 48.5 mA. Also, the values of the fill factors and efficiencies of the devices are 0.7% and approximately 13.6%, respectively. In addition, PC-AFM, a recent notable method for nano-scale characterization of photovoltaic elements, was used for direct measurements of photoelectric characteristics in local instead of large areas. The effects of changes in the intensity and wavelength of light shining on the element on the photoelectric characteristics were observed. Results obtained through PC-AFM were compared with the electric/optical characteristics data obtained through a solar simulator. The voltage ($V_{PC-AFM}$) at which the current was 0 A in the I-V characteristic curves increased sharply up to 1.8 $mW/cm^2$, peaking and slowly falling as light intensity increased. Here, $V_{PC-AFM}$ at 1.8 $mW/cm^2$ was 0.29 V, which corresponds to 59% of the average $V_{oc}$ value, as measured with the solar simulator. Also, while light wavelength was increased from 300 nm to 1,100 nm, the external quantum efficiency (EQE) and results from PC-AFM showed similar trends at the macro scale, but returned different results in several sections, indicating the need for detailed analysis and improvement in the future.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.2
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• pp.113-120
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• 2002

This paper describes characteristics of transient voltage waveforms caused by human electrostatic discharges(ESDs). For purpose of achieving the statistics on the meaningful amplitude and initial slope for transient ESD voltage waveforms, transient voltages due to human ESDs in various conditions were observed. A voltage measuring system with a wide bandwidth from DC to 400[MHz] was employed. ESD voltage waveforms are approximately the same as ESD current waveforms. Also the simulated results, which are calculated by the reposed equivalent circuit, are closely similar to the measured voltage waveforms. ESD voltage waveforms are strongly dependent on the approach speed and material of intruder, a fast approach causes ESD voltage waveform with a steep rise time than for a slow approach. The voltage waveforms from dialect finger ESDs have a relatively long rise time of 10∼30[ns], but their peaks are low. On the other side ESD voltage waveforms causer by screwdriver with insulating handle have a steep slope with a very short, less than 1[ns] rise time, but their initial spikes are extremely high The obtained results in this work would be applied to solve ESD problems for low voltage and small current electronic devices.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.4
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• pp.10-15
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• 2013

In order to fabricate high sensitive and stable biosensors, we require the material with superior biocompatibility and physical-chemical stability. Many kinds of biomaterials have been evaluated to apply for bioindustry. Recently, carbon based diamond thin films have been focal pointed as bio-applications and their possibility has been evaluated. Diamond thin film has many advantages for electrochemical and biological applications, such as wide potential window (3.0-3.5V), low background current and chemical-physical stability. In this work, we have cultured neuroblastoma cell (SH-SY5Y) on the crystalline diamond films. We use MTT assay to evaluate the characteristic of cell culture on the substrates. As a result, neuroblastoma cell was cultured on the crystalline diamond film as similar as cell culture dish.