• Journal of the Korea Computer Graphics Society
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• v.24 no.3
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• pp.33-41
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• 2018

We present a secondary camera optimization method that helps the user exploring 3D virtual environment to precisely observe possible collisions between objects. The first role of our secondary camera is to automatically detect the area with the greatest possible collision. The second role is to show the detected area from a new angle of view that the current main camera cannot show. However, as the shapes of target objects are complex, the shape of the empty space between objects is also complex and narrow. It means that the space for the secondary camera position is highly constrained and its optimization can be very difficult. To avoid this difficulty and increase the efficiency of the optimization, we first compute a bisector surface between two target objects. Then, we limit the domain of the secondary camera's position on the bisector surface in the optimization process. To verify the utility of our method, we built a demonstration program in which the user can explore in a 3D virtual world and interact with objects by using a hand motion recognition device and conducted a user study.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.1
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• pp.59-66
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• 2005

[ $TiO_2$ ] was deposited by DC magnetron sputtering on glass surface under various sputtering parameters such as discharge power($0.6{\sim}5.2\;kW$, substrate temperature($R.T{\sim}350^{\circ}C$), Ar and $O_2$ flow ratio with $0{\sim}50\;sccm$($Ar+O_2$ 90 sccm) and about 1 mtorr of pressure. TiO-N thin film was prepared under same sputtering conditions for $TiO_2$ thin film except flow ratio($Ar+O_2+N_2$ 90 sccm). The sheet resistance of thin films deposited under these parameters was measured to analyze electronic characteristic and thin film's thickness(${\alpha}$-step), surface roughness(AFM) and formation construction(FE-SEM, XRD) were also measured to draw optimal sputtering parameters. In order to evaluate photo-activity of thin film($TiO_2$, TiO-N) made in optimal parameters for removal of pollutants, toluene among VOCs and Suncion Yellow among reactive dyes were chosen to probe organic compounds for photo-degradation. It was shown that the photo-catalytic thin films had a significant photo-activation for the chosen contaminants and especially TiO-N thin film showed maximum efficiency of 33% for toluene(5 ppm) removal in visible-light range.

• Korean Journal of Food Science and Technology
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• v.12 no.1
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• pp.45-52
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• 1980

The nylon (poly 6, 10) microcapsules containing ${\beta}-galactosidase$ were obtained by the interfacial polymerization of 1, 6-diaminohexane and sebacoyl chloride with ${\beta}-galactosidase$ from Escherichia coli. They were generally spherical and had a mean diameter of $80{\mu}$ with 45 % of the activity recovery. In particular, there was no transport hamper of lactose through the membrane of microcapsules. The characteristics of the microencapsulated enzyme were similar to those of soluble enzyme optimal pHs, $7.0{\sim}7.2$ for the soluble and $7.3{\sim}7.5$ for the microencapsulated ; optimal temperatures, $50^{\circ}C$ for both ; apparent $K_m,\;3.33{\times}10^{-4}(on ONPG),$ $2.86{\times}10^{-3}$ M(on lactose) for the soluble and $5.28{\times}10^{-4}$ (on ONPG), $4.25{\times}10^{-3}$ M (on lactose) for the microencapsulated ; activation energies, 8.94 for the soluble and 9.78 Kcal/mole for the microencapsulated enzyme. Using this microencapsulated ${\beta}-galactosidase$, hydrolyses of lactose and milk lactose were carried out and 80 % of 5 % lactose solution and 70 % of lactose in skim milk were hydrolyzed in 40 hr at $27^{\circ}C$. The reusability and operational stability showed that the remaining activity was 50 % of the original activity after 5 runs and 120 hr of total operating time at $27^{\circ}C$.

• Korean Journal of Construction Engineering and Management
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• v.17 no.2
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• pp.31-38
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• 2016

In a construction project, the portion for maintenance costs for a building is considerable compared to the initial construction cost. As such, Life Cycle Cost (LCC) analysis is being increasingly utilized to assess the design value of engineering work in Korea. Additionally, the Public Procurement Service in Korea announced that it will be mandatory for all domestic construction projects to adopt BIM. Furthermore, the paradigm for architectural design has shifted from 2D to 3D, and to BIM, which includes a data management system. Within this background, however, there is currently no adequate BIM-based LCC analysis software and the requirements of cost estimation for repair and replacement cost for a building is not completely adequate in BIM tools such as Revit and Archicad. Therefore, this study suggests a process of cost estimation for repair and replacement (R&R) cost based on IFC data. First, we analyzed existing R&R criteria and defined BIM-based requirements when calculating R&R costs. These requirements were extracted from relevant IFC data. Subsequently, this was saved to a database and a BIM-based database was built for R&R cost estimation. Finally, this database was connected with external databases such as R&R Criteria DB and Cost Information DB to calculate R&R costs. This process is expected to improve upon the traditional process of cost estimation of R&R cost by applying a BIM model. The proposed process can contribute to a further standardizing of BIM-based LCC analysis thru application to initial construction costs, energy costs, and other maintenance costs.

• Applied Chemistry for Engineering
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• v.26 no.2
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• pp.165-172
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• 2015

Quercetin and its glycoside, rutin, are flavonoids, which are well known as natural antioxidants. In this study, cationic liposomes loaded with flavonoids (quercetin or rutin) were investigated for their effects on cell and skin permeability, and protective effects against UVA. The particle size of the empty cationic liposomes was in the range of 100~130 nm, and the zeta potential was + 33.05 mV. The entrapment efficiency of 0.5R/CL was higher than that of 0.5 Q/CL. The cellular uptake of the cationic liposomes was five-fold higher than that of liposomes. The skin permeability of quercetin and rutin was investigated using Franz diffusion cells. Compared to the initial loading dose, the amount of quercetin or rutin delivered to the skin by cationic liposomes was higher than that delivered by conventional liposomes or phosphate-buffered saline. From the protective effect of cationic liposomes against UVA ($25J/cm^2$), we found that the cell viability in cationic liposomes containing flavonoids was higher than that of using UVA irradiation only. These results indicate that cationic liposomes provide enhanced delivery of flavonoids (quercetin and rutin) into the skin and may be used for antiaging and antioxidant cosmetics.

• Applied Chemistry for Engineering
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• v.29 no.3
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• pp.356-361
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• 2018

It is common to analyze volatile organic compound (VOC) or semi-VOC (SVOC) in a sample composed of a complex matrix consisting of multiple components such as bloods through a separation process. Adsorption is a physical phenomenon in which certain components accumulate on the surface of other phases. In order to overcome difficulties in the pretreatment process, an adsorption is frequently used. Solid phase microextraction (SPME) equipment with porous carbon carboxen (CAR) is an example of adsorption application. In this study, the adsorption of 4-octylphenol to carboxen was examined. To do so, the extraction efficiency for such solvents as dichloromethane ($CH_2Cl_2$, DCM), ethylacetate ($CH_3COOC_2H_5$, EA) and diethylether ($C_2H_5OC_2H_5$, $Et_2O$) was studied and also the derivatization reaction for 4-octylphenol with reagents of bistrimethylsilyltrifluoroacetamide (BSTFA), methylchloroformate (MCF) and pentafluorobenzylbromide (PFBBr) was compared. The combination of DCM and BSTFA showed good performance thus they were adopted for this study. Thermodynamic adsorption experiments showed that the adsorption process was endothermic and Freundlich isotherm equation was more suitable than Langmuir isotherm. It was also found that the adsorption followed a pseudo-$2^{nd}$ order kinetic model.

• Journal of Life Science
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• v.10 no.3
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• pp.273-278
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• 2000

The chemical compositions as amino acids, minerals, fatty acids, and total polyphenolic compounds of the seeds of leek (Allium tuberusum) were analyzed. The antioxidative activity of water soluble extract from leek seeds was also tested in DPPH ($\alpha$, $\alpha$ - diphenyl-$\beta$ -picrylhydrazyl) method. The chemical compositions of leek seeds were moisture 4.4%, curde protein 25.7%, crude fat 16.6%, and crude ash 2.9%. Major amino acid compositions were proline 11 g, glutamic acid 4.9 g, arginine 2.1g, aspartic acid 1.6g, leucine 1.3g, valine 1.2 g, and methionine 1.1 g as per 100g. Mineral contents were K 215 ppm, Ca 142 ppm, Fe 124 ppm, and Mg 100 ppm. Major fatty acid compositions were linoleic acid 71.9%, oleic acid 12.7%, palmitic acid 8.6%, and stearic acid 1.4%. The changes of contents in polyphenolic compound from leek seeds caused by heat treatment were also listed in the following order; $20^{\circ}C$(364mg/100g), $40^{\circ}C$(462 mg/100g), and $60^{\circ}C$(551 mg/100g). Antioxidative activity as electron donating ability showed in the following order; 0.05% BHT(butylated hydroxytoluene)(45.6%)>0.05% water-extract(31.3%)>0.1% water extract(30.3%). On the basis of chemical analysis, the leek seedsshowed to have relatively high contents of nutrients as amino acids, minerals, fatty acids.

• Journal of Broadcast Engineering
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• v.19 no.6
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• pp.767-788
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• 2014

The worldwide transition from analog to digital broadcasting has now been completed and the need to study next generation standards for Ultra High Definition TV (UHDTV) broadcasting, and broadcasting & communication convergence systems is rapidly growing. In particular, high resolution mobile broadcasting services are needed to satisfy recent consumers. Therefore, the development of highly efficient convergence broadcasting systems that provide fixed/mobile broadcasting through a single channel is needed. In this paper, a service scenario and requirements for providing 4K UHD & HD convergence broadcasting services through a terrestrial single channel are analyzed by employing the latest transmission and A/V codec technologies. Optimized transmission parameters for 6 MHz & 8 MHz terrestrial bandwidths are drawn, and receiving performances are measured under Additive White Gaussian Noise (AWGN) and time-varying multipath channels. From the results, in a 6 MHz bandwidth, the reliable receiving of HD layer data can be achieved when the receiver velocity is maximum 140 Km/h and is not achieved when the velocity is over 140 Km/h due to the limit of bandwidth. When the bandwidth is extended to 8 MHz, the reliable receiving of both 4K UHD and HD layer data is achieved under a very fast fading multipath channel.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.6_1
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• pp.471-481
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• 2013

Recently, the frequency of debris flow disaster has increased, which is one of the natural disasters during extremely heavy rainfall condition. This paper described the analysis method about deposition characteristics of debris flow using topographic characteristics of debris flow path. First, we observed topographic changes by differencing high- resolution LiDAR DEMs acquired before and after the occurrence of debris flow event. We assumed that deposition on outside of debris flow path was generated by movements due to the inertia of debris flows. Then, we analyzed three topographic characteristics of debris flow path: slope in flow direction, transition angle of flow path, and the net efficiency(L/H) of debris flows defined by the ratio of transport length(L) and elevation difference(H). We applied this method to Umyeon Mountain debris flow event in July 2011. The results showed that deposition on outside of debris flow path due to the inertia of debris flows was significantly related to the transition angle of debris flow path. Also, we figured out that there were more frequent such depositions in locations where the ratio of 'transition angle / (L/H)' is over 8.

• Journal of Chest Surgery
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• v.33 no.11
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• pp.863-868
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• 2000

배경: Cox-Maze III (CM-III) 술식은 복잡한 심방 절개로 인한 긴 수술시간 때문에 다른 개심 수술과 병행하여 시행하기 어려운 단점이 있다. 대상 및 방법: 저자들은 CM-III 술직을 다음과 같이 변형하여 시행하고 그 임상성적을 분석하였다. \circled1 좌심방이를 절제하는 대신 좌심방이를 외부에서 결찰하고, \circled2 폐정맥 분리 절개선과 좌심방이 사이에 냉동절제술을 시행하며, \circled3 우심방이를 절제하는 대신에 우심방 외측 절개선을 우심방이까지 연장하고, \circled4 후종 우심방 절개 하부에서 우심방 외측을 지나 삼첨판막륜으로 향하는 T-자 절개선을 생략하였다. 저자들이 시행한 변형 술식의 용이성과 효율성을 평가하기 위하여, 우리나라에서도 빈도가 높은 류마치스성 승모판막 질환에서, 전통적인 Cox-III 술식(그룹 I)의 임상결과와, 변형된 CM-III 술식(그룹 II)의 임상결과를 비교하였다. 결과: 그룹 I(n=18)에서 동반된 수술은 승모판막 치환술 10례, 승모판막 성형술3례, 승모판막 치환술과 삼첨판막륜 성형술3례, 승모판막 재치환술 2례 등이었다. 그룹II(n=23)에서 동반된 수술은 승모판막 치환술 7례, 승모판막 성형술 5례, 승모판막 치환술과 삼첨판막륜 성형술 1례, 승모판막 재치환술 10례 등이었다. 그룹 I과 그룹 II에서 평균 대동맥 차단 시간(ACC)은 각각 135$\pm$29분과 104$\pm$18 분, 심패바이패스(CPB) 시간은 각각 240$\pm$33분과 185$\pm$42분이었다. 그룹 I과 그룹 II의 평균 추적 관찰 기간은 각각 47$\pm$14 개월과 29$\pm$4 개월이었다. 그룹 I에서는 16례(88.9%)에서 정상 동율동으로 회복되었고 1례에서 심방세동이 남아 있었으며, 다른 1례는 서맥증후군(sick sinus syndrome)으로 인공 심박조율기를 삽입하였다. 그룹 II에서는 21례(91.3%)에서 정상 동율동으로 회복되었고 2례는 심방세동이 지속되었다. 그룹 I에서 정상동율동으로 회복된 16례는 100%(16/16)에서 우심방의 수축을 심장 초음파검사에서 확인할 수 있었으며, 좌심방의 수축은 75%(12/16)에서 확인할 수 있었다. 그룹 II에서는 정상 동율동으로 회복된 21례 중 100%(21/21)에서 우심방의 수축을 확인할 수 있었으며, 좌심방의 수축은 76.2%(16/21)에서 확인할 수 있었다. 결론: 변형 CM-III 술식은 전통 CM-III 술식에 비하여 ACC time(p<0.005)과 CPB time(p<0.001)을 의미있게 줄이면서도 필적할 만 한 정상 동율동 전환율과 심방 수축력의 회복을 보여주었다.