• Journal of Korea Foundry Society
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• v.17 no.5
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• pp.419-425
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• 1997

용탕단조방법에 의해 제조된 Mg-6Al-xZn(x=0, 1, 2)합금의 기계적 성질에 미치는 시효열처리의 영향을 조사한결과 아래와 같은 결론을 얻었다. (1) 주조조직을 관찰한 결과 미세한 수지상조직을 나타냈으며 초정${\alpha}$, 과포화 ${\alpha}$, ${\beta}$상 등 세가지 상으로 구성되어 있었다. (2) Mg-6Al-xZn합금은 시효경화성을 나타내었으며 Zn의 첨가량이 증가할수록 전시효구간에서 경도값이 높게 나타났다. (3) 시효조직을 관찰한 결과 $200^{\circ}C$의 시효시에는 불연속 석출물이 대부분 차지했으나 $240^{\circ}C$의 시효온도에서는 수지상 경계에서 시작되는 미세분산된 연속석출물이 대부분 이었다. (4) $240^{\circ}C$에서 시효열처리 한 시편은 연속석출물이 석출됨으로서 $200^{\circ}C$에서의 시효열처리된 시편에 비하여 과시효되는 경향이 작았다. (5) T6열처리 후 인장시험 결과 Zn 첨가량에 따라 강도가 증가하였는데 Mg-6Al-2Zn합금의 경우 인장강도는 248.4 MPa을 나타내었으며 Zn양에 따른 연신율의 감소는 나타나지 않았다.

• Analytical Science and Technology
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• v.6 no.2
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• pp.149-156
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• 1993

The formation of the graphite spherulites has been studied experimentally in the Ni-C liquid under high pressure and temperature. In the diamond-stable region the graphite spherulites were formed and grew stably. They were not the polycrystalline particles but the single crystals of the fullerene-type, respectively, grown spirally with much imperfection. And they were proved to be in a mixture state of carbon atoms with $sp^2$- and $sp^3$-bonding by an Auger electron spectroscope and a high resolution transmission electron microscope. As the pressure decreased from the diamond-stable region to the graphite-stable region, the shape of the graphite particles changed gradually from the sphere to the flaky shape. The formation of the graphite spherulites was attributed to the stable existence of the carbon atoms with $sp^3$ bonding in the diamond-stable region. The formation of the large fullerene-type graphite spherulites with much imperfection is well agreed with Kroto's prediction for growth of the giant fullerene.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.331-334
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• 2006

In this study, the ultra-fine fibers (UFs) having an alignment were prepared by electrospinning process, using different collectors made from various materials and collecting methods. A spinning solution was prepared by dissolving poly(amide-co-imide) (PAI) in NMP. The UFs were prepared by using various collectors and collecting methods, and the fibrous shapes were observed by SEM. As a result, a sort of materials of collectors and the collecting methods had not influenced on the average diameters of fibers but the forms of them. The just accumulated UFs on the collectors formed net structures, which had no alignment. On the contrary, the continuously collected UFs formed long fibers with alignment. It was found that the water collector played the roles of the fiber haul, temporary collector, moving path of fibers, and caused some friction between fibers and water, attributed to the formation of continuous UFs at a suitable collecting speed.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.06a
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• pp.1253-1255
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• 2022

예능 프로그램에서 관찰예능 포맷은 널리 사용되는 형태이다. 본 연구에서는 AI기반 리프레이밍 기술을 활용하는 새로운 관찰 예능 제작 기법을 제안한다. 제안방식은 실제 방송프로그램 KBS2 신상출시 편스토랑에 적용되었다. 연구의 조건에 부합하는 촬영 장비의 기능조건과 조사결과를 다룬다. 센서타입와 연속녹화시간은 장비선정에 있어 핵심 고려요소로 나타났다. 시스템 구성은 제작 워크플로우에 따라 촬영파트와 편집파트로 나누어 소개한다. 촬영파트는 실제 제작현장의 기록을 바탕으로 작성되었다. 편집파트의 경우 자체 개발한 편집도구로 이루어지며, 핵심모듈인 AI엔진과 고속렌더링모듈에 대한 소개를 하였다. 향후 최신 촬영 장비의 도입, 처리성능의 향상 등을 통해 제안방식의 적용처를 넓혀갈 수 있을 것으로 기대한다.

• Korean journal of applied entomology
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• v.36 no.4
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• pp.299-310
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• 1997

A mutant, or(orange body), and the KNIH(Korea National Institute of Health) strain of the German cockroach, Blattella germanica(L.) (Orthoptera: Blattellidae), were observed continuously in semi-natural conditions through video taping and data processing by computers. Male adults were individually observed for 4-5 days in a rectangular-shaped rearing cage with four different microhabitats, allowing observations of behavior such as resting, feeding, drinking and communicating with other individuals. The frequencies of visits to and times spent within harborage were determined. Although there were relatively large variations among individuals, the average stays withing harborage ranged from 47-61% of the total observation time. The duration of within-harborage time was significantly different between maternal origins, while not distinctively different between the strains. Diel differences were observed in body strains. The time spent within harborage was longer in photophase than in scotophase. visiting frequency, which represented local activity around harborage, appeared slightly higher in the or strain than in the KNIH strain, and was significant in the or strain while it was not significant in the KNIH strain. Although there were variations among individuals, similar temporal patterns in some progenies from the same maternal origins were observed in time spent within harborage and in visiting frequency.

• Journal of the Korea Concrete Institute
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• v.15 no.2
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• pp.163-172
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• 2003

As concrete structures are getting larger, higher, longer, and specialized, it is more required to develop steel fiber concrete and apply to the real world. In this research, it is aimed to have fatigue strength examined, varying the steel fiber content by 0%, 0.75%, 1.00%, 1.25%, by experimental study of Two-spans Beam with Steel Fibrous with repeated loads. The ultimate load and the initial load of flexural cracking were measured by static test. In addition, the load versus strain relation, load versus strain relation, load versus deflection relation, crack pattern and fracture mode by increasing weight was observed. On the other hand, the crack propagation and the modes of fracture according to cycle number and the relation of cycle loading to deflection relation and strain relation was observed by fatigue test. As the result of fatigue test, Two-spans Beam without Steel Fibrous was failed at 60~70% of the static ultimate strength and it could be concluded that fatigue strength to two million cycle was around 67.2% by S-N curve. On the other hand, that with Steel Fibrous was failed at 65~85% of the static ultimate strength and it could be concluded fatigue strength to two million cycle around 71.7%.

• Korean Journal of Plant Resources
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• v.15 no.1
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• pp.26-35
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• 2002

Abeliophyllum distichum Nakai (O1eaceae) is a monotype of Korea and is distinguished from related genus Forsythia Vahl by the morphological characters such as fruit shape, flower color and etc. Even though several intraspecific taxa were reported according to the color of flowers and shape of fruits, there have been many controversals on the taxonomic indentity and status of rank on those taxa. In the present study, we performed the RAPD analysis to delimit the infraspecific taxa of Abeliophyllum distichum and to investigate the genetic polymorphism and relationships among 12 populations. 212 scorable RAPD markers with 70 common markers were found from the PCR reactions with 16 random oligoprimers and were analyzed by Nei's genetic distance. From 0.108 to 0.321 of genetic variations were showed among the taxa. Some regional groups instead of same taxa were clustered from the phonogram of UPGMA analysis. Also, we could not find distinct lineage among intraspecific taxa. The result from RAPD analysis supported that the infraspecific taxa of Abeliophyllum distichum might be the individual variations and treated as the same taxa. RAPD analysis was very useful to confirm the high gene pool with diverse genetic polymorphism among Abeliophyllum distichum populations.

• Journal of the Korean GEO-environmental Society
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• v.15 no.4
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• pp.37-41
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• 2014

Pulse electrokinetic technology is proposed for improving the dewatering-process from clay-sandy soil. Proposed electrokinetic technology is to be the dewatering process due to fluid movement of current flow for the stability of clay-sandy soils. Samples produced in this study were completed to verify the proposed performance for 7 days by gradually increasing the pressure to the final pressure of 30 psi ($2.11kgf/cm^2$) through the compression process. In this study, pulse electrokinetic treatment and conventional continuous electrokinetic treatment are tested and observed, respectively. The condition of continuous electrokinetic treatment is a continuous process during 48 hours. And the condition of pulse electrokinetic treatment system is to interrupt the power three times for 48 hours, every 8 hours. These treatments are that the voltage gradient is 3 V/cm. As a result, the efficiency of pulse electrokinetic is similar to the continuous electrokinetic. The power consumption efficiency of pulse electrokinetic is better than continuous electrokinetic.

• Composites Research
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• v.23 no.3
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• pp.43-49
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• 2010

Basaltic fiber was prepared by continuous spinning process from Jeju Pyosun raw basalt materials. First, for confirming the melting characterization of basalt, basalt raw material put into Pt crucible and melted up to $1550^{\circ}C$ then quenched by dropping it into water. After quenching, the optimum fiber spinning conditions were investigated by measurement and analysis of XRD, TMA, high temperature viscosity, high temperature conductivity and high temperature microscope. The optimum spinning temperature and viscosity for preparation of continuous filament fiber were $1264^{\circ}C$ and $10^{2.8}$ poise at $1264^{\circ}C$, respectively. Properties of prepared spinning fiber were confirmed by tensile strength, FE-SEM, heat resisting test and others. The tensile strength of fiber prepared by spinning conditions of the bushing temperature $1240^{\circ}C$ and winder speed 4600rpm was 3660MPa.

• The KIPS Transactions:PartA
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• v.16A no.2
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• pp.79-88
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• 2009

In boundary scan architecture, test stimuli are shifted in one at a time and applied to the on-chip system logic. The test results are captured into the BSR and are examined by subsequent shifting. In this paper, we developed a continuous capture test architecture and test procedure using TPG based on boundary scan is used to performance test. In this architecture, test patterns of TPG are applied to CUT with system clock rate, and response of CUT is continuously captured by CBSR(Continuous Capture Boundary Scan Register) at the same rate and the captured results is shifted to TDO at the same rate. The suggested a continuous capture test architecture and test procedure is simulated by Altera Max+Plus 10.0. The simulation results shows the accurate operation and effectiveness of the proposed test architecture and procedure.