• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.1720-1723
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• 2012

과학기술,사회(STS, Science and Technology in Society)란 과학과 기술을 역사적이고 사회학적인 시각으로 바라보자는 관점을 뜻한다. 이는 시민들이 이런 시각을 가져야 과학기술과 관련된 사회 쟁점에 대한 올바른 판단이 가능하다는 의미이다. 이를 위해 국가 교육과정체제 이후의 평생교육으로써 성인을 대상으로 하는 과학문화 소통 프로그램이 필요하다. 본 논문은 국내와 해외의 성인 대상의 과학 문화 프로그램을 분석하여 올바른 과학문화 소통을 위한 프로그램 과정은 어떤 모습으로 설계되어야 하는지를 제안한다. 제주대학교 과학기술사회연구센터(STS연구센터)에서 연구하고 있는 제주 특성을 활용한 과학기술문화교육 프로그램을 소개하고, 향후 정보과학 기반의 연구방향도 소개하고자 한다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.7 no.1
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• pp.15-32
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• 1997

본 논문에서는 스트림 암호 시스템에서 사용이 되는 LFSR 을 이용한 이진 수열 발생기중 하나인 Threshold 발생기에 대한 광학적 구현 방법을 새로이 제안하였다. 광학적 구현을 위하여 LCD를 이용하므로서 LFSR 및 Mod 덧셈 연산을 위한 각 비트 값을 표현, 2차원 처리가 가능하게 하였다. Thredshold 발생기의 LFSR기능은 Shdow Casting 기법을 이용하여, 또한 XOR 연산 및 내적 계산을 위한 MOD덧셈 연산은 LCD 가 갖고 있는 편광 특성을 이용하여 광학적으로 구현하였다. 특히 본 논문에서는 Mod 2 덧셈 연산을 위한 새로운 광학적 구현 방법인 RSPM 을 제안하므로서 연산 결과 값 측정과 LCD 상의 데이타 값 표현 과정을 제외한 전 부분을 완전한 광학적 방법으로 처리가 가능하게 하였다. 본 논문에서 제안한 광 Threshold 암호 시스템은 기존의 전자적인 H/W 구현 방법에서 문제가 되어오던 Tapping Point의 개수에 대한 한계성을 극복할 수 있는 장점을 지니고 있으며, 또한 2차원 데이타인 영상용 암호화 시스템의 광학적 구현에 그 응용이 가능하다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.899-904
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• 2001

The impact of PVD coatings can be summed up in practical terms: this technology historically complements the best designed tool substrates to enhance cutting performance. PVD coatings are now incorporated in 25% of all HSS tools. The functionality is to extend the machining speed range, improve wear resistance at the cutting edge, and reduce friction at chip/tool contact areas to allow easier chip evacuation. These translate to a larger safe zone, as discussed in the failure mode diagram, for better productivity and higher reliability in machining operations of the customer. PVD coatings therefore represent an enabling technology that extends the application range of cutting tools in response to modern industrial needs. PVD coatings prolong the product life cycle of HSS tools and help this "mature" material to hold its territory against the advent of the newer hardmetal and ceramic tool materials. There is a lot of competitive life left particularly in PVD coated HSS endmills, drills, threading/tapping tools. PM HSS technology further increases the possibilities.ibilities.

• Journal of Ceramic Processing Research
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• v.13 no.spc1
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• pp.145-148
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• 2012

Spherical silica aerogel powders were fabricated via an emulsion polymerization method from a water glass. A water-in-oil emulsion, in which droplets of a silicic acid solution are emulsified with span 80 (surfactant) in n-hexane, was produced by a high power homogenizer. After gelation, the surface of the spherical silica hydrogels was modified using a TMCS (trimethylchlorosilane)/n-hexane solution followed by solvent exchange from water to n-hexane. Hydrophobic silica wet gel droplets were dried at 80 ℃ under ambient pressure. A perfect spherical silica aerogel powder between1 to 12 ㎛ in diameter was obtained and its size can be controlled by mixing speed. The tapping density, pore volume, and BET surface area of the silica aerogel powder were approximately 0.08 g·cm-3, 3.5 ㎤·g-1 and 742 ㎡·g-1, respectively.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.23-24
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• 2023

In this study, an easily recyclable separable glued-laminated timber (GLT)-steel beam was developed, and a structural design method was presented. The GLT and steel were mechanically composited using self-tapping screws. The GLT-steel beam was designed to fail in the compression of GLT. The bending moment and load-carrying capacity of the GLT-steel beam were predicted based on composite beam theory and compared with experimental test data. As a result, the GLT-steel beam exhibited ductile behavior, and compression failure of GLT was observed. The screw connection showed no damage while the steel plate was extended. The load-carrying capacity of GLT after failure was similar to the load resistance predicted by the compressive strength of GLT and the tensile strength of steel. This indicates that the ductile behavior of the GLT-steel beam can be safely designed by the tensile strength (yield) of steel.

• Journal of the Korean Wood Science and Technology
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• v.48 no.2
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• pp.206-216
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• 2020

This study was conducted to analyze the sap flow and composition by tapping date in Acer akamotoanum from an artificial forest in the City of Jinju. The sap was collected from five saplings (diameter at breast height10-20 cm) in two phases with an interval of a month. During phase 1 (January 10, 2019 - February 9, 2019) with daily mean temperature of 1.16±2.15℃, 60.59 liters of sap was collected over 32 days. Phase 2 (February 12, 2019 - February 22, 2019) with daily mean temperature of 2.55±1.30℃ yielded 13.38 liters of sap over 11 days, which was a reduction to 22% of the total sap flow in phase 1. The analysis of sugar composition in the collected sap from phase 1 and 2 showed that sucrose concentration was 2.5% at its highest during the earlier days of collection and decreased to 0.8% at the end. Glucose and fructose concentrations were measured near 0, and were lower than sucrose concentration. The most prominent inorganic elements in the collected sap were potassium (41.69 - 89.75 mg/kg), calcium (24.66 - 48.14 mg/kg) and magnesium (10.18 - 27.25 mg/kg). The contents of sucrose and inorganic components between the samples collected from phase 1 and 2 did not show significant differences. The sap flow amounts of A. okamotoanum from different tapping periods showed a notable variation, but there were no significant differences in the contents of sugar or inorganic elements.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.3
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• pp.207-214
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• 2015

Due to the limitations of conventional removable partial denture prostheses to treat a cleft lip & palate patient who shows scar tissue on upper lip, excessive absorption of the maxillary residual alveolar ridge, and class III malocclusion with narrow palate and undergrowth of the maxilla, 4 implants were placed on the maxillary edentulous region and a maxillary removable implant-supported partial denture was planned using a CAD/CAM milled titanium bar. Unlike metal or gold casting technique which has shrinkage after the molding, CAD/CAM milled titanium bar is highly-precise, economical and lightweight. In practice, however, it is very hard to obtain accurate friction-fit from the milled bar and reduction in retention can occur due to repetitive insertion and removal of the denture. Various auxiliary retention systems (e.g. $ERA^{(R)}$, $CEKA^{(R)}$, magnetics, $Locator^{(R)}$ attachment), in order to deal with these problems, can be used to obtain additional retention, cost-effectiveness and ease of replacement. Out of diverse auxiliary attachments, $Locator^{(R)}$ has characteristics that are dual retentive, minimal in vertical height and convenient of attachment replacement. Drill and tapping method is simple and the replacement of the metal female part of $Locator^{(R)}$ attachment is convenient. In this case, the $Locator^{(R)}$ attachment is connected to the milled titanium bar fabricated by CAD/CAM, using the drill and tapping technique. Afterward, screw holes were formed and 3 $Locator^{(R)}$ attachments were secured with 20 Ncm holding force for additional retention. Following this procedure, satisfactory results were obtained in terms of aesthetic facial form, masticatory function and denture retention, and I hereby report this case.

• Journal of Korea Entertainment Industry Association
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• v.13 no.4
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• pp.369-375
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• 2019

This study looked at the effects of teratainment taping and footpad exercise on the improvement of flat foot in a university student. We divided it into flexible flat foot taping group(n=13), flexible flat foot exercise group(n=14), rigid flat foot taping group(n=12), rigid flat foot exercise group(n=13) through a navicular drop test. After one hour's application of teratainment taping and footpad exercise, the height change of navicular, balancing ability and postural stability were evaluated. Change in the height of the navicular was measured before and after intervention, and the balancing ability was measured timed up & go test, and the postural stability ability was evaluated for stability limits in shoulder-width double leg stance, narrow base double leg stance, tandem stance. According to result, there was a statistically significant difference in the left and right foot of the flexible tapping group, right foot of the flexible tapping group, right foot of the rigid tapping group in the change in the height of the navicular in comparison pre- and post- intervention(p<0.5). There were no statistically significant differences in pre- and post- intervention comparisons intragroup and intergroup in balancing ability. There was a statistically significant difference in flexible flat foot exercise group and rigid flat foot taping group in tandem stance in comparison pre- and postintervention in the postural stability(p<0.5). And there was a statistically significant difference in tendem stance of the flexible flat foot exercise group compared to the rigid flat foot exercise group(p<0.5). The results of this study show that teratainment taping and footpad exercise have a significant effect on the improvement of flat foot in adults. Therefore, it is recommended to apply teratainment taping and footpad exercise to improve flat foot.

• Journal of Yeungnam Medical Science
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• v.14 no.1
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• pp.183-196
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• 1997

An experimental study was performed to investigate. The subjects drank (0.5g/kg ethanol and performed 7 items of SPES(simple reaction time, color word stress, digit classification, finger tapping speed, numerical ability, symbol digit coding, memory digit span). 20 students of medical college participated in the study during August, 1996. After ethanol intake, performance of 4 items(simple reaction time, digit classification, finger tapping speed, symbol digit coding) significantly showed to be decreased. The function of perception-response speed and steady movement were found to be more sensitive to ethanol than that of short-term memory, numerical ability and specification of color. No significant association were found between smoking, alcohol drinking, BMI(body mass index) and the effects of ethanol on neurobehavioral performance.

• Environmental Analysis Health and Toxicology
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• v.28
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• pp.15.1-15.8
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• 2013

Objectives The aim of this study was to determine the association between low-level mercury exposure and neurobehavioral functions in adults living in coastal regions of Korea. Methods We selected 172 adults aged 20-65 years living in a city in the coastal region of Korea. A sociodemographic survey was conducted, mercury levels in the blood, urine, and hair were measured, and the associations according to computerized neurobehavioral tests were determined using univariate analysis. After adjustment for associated variables, a multivariate linear regression analysis was performed. Results The geometric mean mercury levels in the blood, urine, and hair were $5.41{\mu}g/L$ (range, $0.00-15.84{\mu}g/L$), $1.17{\mu}g/g$-creatinine (range, $0.00-32.86{\mu}g/g$-creatinine), and 1.37 mg/kg (range, 0.42-6.56 mg/kg), respectively. Variables that were associated with simple reaction time according to the neurobehavioral test results were age and urine mercury level. Variables associated with choice reaction time were the recent use of Korean traditional medicine and urine mercury level. Variables associated with the right-hand finger tapping speed test were age, gender, smoking behavior, education level, monthly household income, and urine mercury level. Variables associated with the left-hand finger tapping speed test were age, gender, education level, and urine mercury level. After adjustment for associated variables, there was no significant association between urine mercury level and simple reaction time (${\beta}=25.96$; p =0.47), choice reaction time (${\beta}=50.37$; p =0.32), or the number of left-hand finger taps (${\beta}=-1.54$; p =0.21). However, urine mercury level was significantly associated with the number of right-hand finger taps (${\beta}=-3.86$; p =0.01). Conclusions We found no evidence that low-level mercury exposure in adults is associated with deficits in neurobehavioral functions. A longer follow-up study is required to confirm this conclusion.