• BMB Reports
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• 제40권2호
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• pp.232-238
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• 2007

The p13 gene is uniquely present in Group II nucleopolyhedroviruses (NPVs) and some granuloviruses, but not in Group I NPVs. p13 gene was first described by our laboratory in Leucania separatamultiple nuclear polyhedrosis virus (Ls-p13) in 1995. However, the functions of Ls-P13 and of its homologues are unknown. When Ls-p13 was inserted into Autographa californica nucleopolyhedrovirus, a Group I NPV, polyhedra yield was inhibited. However, this inhibition was prevented when the leucine zipper-like domain of Ls-p13 was mutated. To determine the cause of this marked difference between Ls-P13 and leucine zipper mutated Ls-P13 (Ls-P13mL), oligomerization and secondary structure analyses were performed. High performance liquid chromatography and yeast two-hybrid assays indicated that neither Ls-P13 nor Ls-P13mL could form oligomers. Informatics and circular dichroism spectropolarimetry results further indicated marked secondary structural differences between Ls-P13 and Ls-P13mL. The LZLD of Ls-P13 has two extended heptad repeat units which form a hydrophobic surface, but it is short of a third hydrophobic heptad repeat unit for oligomerization. However, the mutated LZLD of Ls-P13mL lacks the above hydrophobic surface, and its secondary structure is markedly different. This difference in its secondary structure may explain why Ls-P13mL is unable to inhibit polyhedra yield.

• 한국가스학회지
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• 제12권4호
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• pp.63-68
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• 2008

본 논문은 적외선 센서의 광 강도 및 효율을 증가시키기 위해 새로운 오목한 반사 벽면(curved mirror surface)과 기존의 수직 반사 벽면(vertical mirror surface)구조와의 모의해석 및 실험 결과에 대해 기술하였다. 모의해석 결과 수직 반사 벽면을 사용했을 때 적외선 센서 필터 표면에 도달하는 광의 분포는 타원 형상으로 적외선 센서 표면에 도달함을 볼 수 있고, 오목한 반사 벽면을 사용하는 경우에는 광이 원형상으로 집광되는 것을 볼 수 있었다. 따라서 초기 평행광의 면적보다 작은 면적으로 집광됨으로 인해 단위면적당 광 강도는 향상되고, 이에 따라 광학적 센서의 출력전압은 향상될 것이라 예측되었다. 이 모의해석을 근간으로 하여 $25^{\circ}C$, 45%R.H.에서 이산화탄소를 0 ppm에서 2500 ppm까지 250 ppm 간격으로 주입시켰을 때, 오목한 반사 벽면의 광 공동이 수직 반사 벽면의 광 공동보다 출력전압이 약 200 mV 증가하였다.

• 한국유체기계학회 논문집
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• 제18권5호
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• pp.26-32
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• 2015

This paper describes performance evaluation of design parameters, air velocity inside a pipeline and pressure along a pipeline, using experimental measurements in an automated vacuum waste collection system. Automatic robot having six cameras is introduced to analyze the internal pipeline conditions whether waste accumulates at the bottom of the pipeline or not. Throughout the experimental measurements of the pipeline having the various shapes, it is found that pressure and internal air velocity linearly increase along the pipeline from a waste inlet to a waste collection station while air density decreases due to the air compression effect with high pressure. Although air velocity inside the pipeline at a waste inlet keeps design velocity range between 20 m/s and 30 m/s, it is noted that air velocity near the waste collection station exceeds maximum design velocity of 30 m/s. Pressure increase per unit length is changed from 17.6 Pa/m to 18.9 Pa/m, which depends on the air velocity inside the pipeline. From the investigation inside the pipeline with CCTV loaded on an automated robot, waste accumulated at the bottom of the pipeline is mainly found at the downstream of a circular curved pipe, an inclined pipe and a bended pipe.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권4호
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• pp.274-279
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• 2002

The purpose of this study is to evaluate the critical maintenance period of absorbable membrane for guided bone regeneration. Fortynine Sprague-Dawley rats weighing about 300g were divided into seven groups. An 8 mm circular full-thickness defect in calvarial bone was made and then cellular acetate porous filter (Millipore $filter^{(R)}$.) was placed on the calvarial bone defect. The filter was removed at 2, 3, 4, 5, 6, 8 and 11 weeks after placement. Rats were sacrificed at 12 weeks the placement of cellular acetate porous filter. The specimens were stained with Hematoxylin-Eosin and observed under light microscope. The amount of regenerated bone was measured from both margin of calvarial bone defect (unit : mm). The results were as follows. Bone regeneration of each experimental group was increased gradually and the bond defect was almost completely filled with new bone in 5-, 6-, 8-, and 11-week experimental group. Histologic findings showed mild inflammatory response and granulation tissue formation without apparent adverse effects on the healing process. In 11-week experimental group, the bone defect was completely filled with new bone containing abundant osteoid which was oriented to the dural side and contribute to bony thickening. We suggest that non-absorbable membrane and bioabsorbable membrane presumably should remain intact for longer than 5 weeks to be effective.

• 대한치과보철학회지
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• 제42권4호
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• pp.412-424
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• 2004

Statement of problem: Several prosthetic options are available for the restoration of multiple adjacent implants. A passively fitting prosthesis has been considered a prerequisite for the success and maintenance of osseointegration. Passivity is a particular concern with multiple implants because of documented inaccuracies in the casting and soldering process. One way to avoid this problem is to restore the implants individually, however, the restorations of individual adjacent impants requires careful adjustment of interproximal contacts. Purpose: The purpose of this study was to compare the stress distribution pattern and amount surrounding Bicon implants with individual crowns and splinted restorations. Material and method: A photoelastic model of a human partially edentulous left mandible with 3 Bicon implants($4{\times}11mm$) was fabricated. For non-splinted restorations, individual crowns were fabricated on 3 abutments ($4{\times}0.65mm,\;0^{\circ}$, 2.0 mm post, Bicon Inc., Boston, USA) After the units were cemented, 4 levels of interproximal contact tightness were evaluated: open, ideal ($8{\mu}m$ shim stock drags without tearing), medium($40{\mu}m)$), and heavy($80{\mu}m$). Splinted 3-unit fixed partial dentures were fabricated and cemented to the model. Changes in stress distribution under simulated non-loaded and loaded conditions(7.5, 15, 30 lb) were analyzed with a circular polaricope. Results: 1. Stresses were distributed around the entire body of fin in Bicon implants. 2. Splinted restorations were useful for distribution of stress around implants especially with higher loads. 3. By increasing the contact tightness between the individually restored three implants, the stress increased in the coronal portion of implants. Conclusions: Ideal adjustment of the contact tightness was important to reduce the stresses around individually restored Bicon implants.

• 한국어류학회지
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• 제22권3호
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• pp.195-200
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• 2010

대구 부화자어 대량방류를 위한 기초 연구로서 대용량 부화기를 이용한 대구 수정란 부화 방법을 검토하였다. 기존의 용량 15L와 시험용 42L인 부화기에 수정란을 수용한 결과 9일째 생존율이 48.3%와 50.4%로 나타나 부화기 용량차이에 따른 생존율은 유의한 차이가 없었다. 제작한 실험 부화기와 기존의 원형수조에서 수정란 생존율을 비교한 결과 40.0~71.2%로 부화기에서 높아 대구 수정란 부화에 실험 부화기가 효율적인 것으로 사료된다. 또한 42 L 부화기에 수정란 5,000 mL (약 825만 개)를 수용하여도 높은 부화율을 유지하였다. 결과적으로 대구 수정란 부화 시 대용량 부화기를 이용할 경우, 고밀도로 수용하여도 높은 수정란 생존율 유지가 가능하고 사육 공간과 인력 및 경비를 절감할 수 있을 것으로 생각된다. 또한 원형수조에 비하여 사육수 절약 (6,700 mL/min)과 수정란 그룹별 수용이 가능하다는 장점이 있다.

• 한국지반환경공학회 논문집
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• 제11권10호
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• pp.15-24
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• 2010

지중전력선은 연성관을 다발로 지하에 매설함으로 관의 하단부 다짐효율이 낮아 파손 등과 같은 구조적 문제점에 항상 노출되어 있고 이러한 문제점을 해결하기 위해서 다양한 방법들이 강구되어 왔으며 그중 하나가 유동성이 뛰어난 저강도 콘크리트의 개발이다. 그러나 지중전력선 뒤채움재는 이러한 구조적 안정성 뿐만 아니라 전력선에서 발생하는 열을 효율적으로 외부로 배출시키는 우수한 열적 특성도 동시에 요구된다. 따라서 본 연구에서는 급결성 유동성 뒤채움재의 물리, 역학적 조건에 따른 열 저항특성을 파악하고자 한다. 국내 토질조건을 고려하여 풍화토, 자갈, 점토를 혼합한 혼합토 총 17종류의 다양한 토양에 대해서 고화재를 적용하여 물리, 역학적 특성(함수비, 단위 중량, 간극비, 양생 시간)에 따른 열저항 특성을 파악하고, 현장의 적용성을 확인하고자 실증실험을 수행하였다. 연구결과, 실제 지반조건과 유사한 17종 혼합토에 대해서 수축팽창, 양생조건을 고려한 실내실험과 현장토에 대해서 실험을 수행한 결과, 다양한 현장조건에 대해서 $85^{\circ}C\;cm/W$ 이하 열 저항성 값으로 우수한 열특성을 나타냈다.

• 한국멀티미디어학회논문지
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• 제13권5호
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• pp.771-779
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• 2010

최근 스케치 인터페이스를 이용한 많은 컨텐츠 제작 기술들이 선보이고 있다. 특히 애니메이션 제작기술 발달로 인해 스케치북에 연필로 선을 그으면 그 선이 그대로 살아 움직이는 애니메이션으로 제작되는 시스템도 선보이고 있다. 본 연구에서는 스케치 인터페이스를 이용해 복수 항공기의 항공기동을 애니메이션하고 학습할 수 있는 시스템을 개발한다. 항공기의 비행은 대부분 3차원 공간상에서 이루어지고 특정한 규칙 없이 이동하는 일반 애니메이션과는 달리 독특하고 복잡한 비행패턴을 가진다. 즉, 가속과 감속, 상승과 하강, 직진과 선회 비행만이 아닌 가속하면서 하강하거나, 감속하면서 상승하는 등 두 가지 이상의 복합적인 이동패턴을 보인다. 이러한 복잡한 이동패턴들로 인해 항공기를 조종하는 조종사와 공중상황을 통제하는 통제요원들은 기존 애니메이션시스템을 이용해 전체적인 항공기동 상황을 학습하기 어렵다. 본 연구에서는 단위경로 스케치 기법을 제안하여 프레임기반의 애니메이션 제작에 비해 적은 입력만으로도 항공기동 애니메이션을 제작할 수 있도록 한다. 또한 제안하는 시스템은 비행경로 사실화 작업으로 복합적인 비행패턴을 지원하여 실제 비행과 유사한 애니메이션이 가능하다.

• 상하수도학회지
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• 제30권3호
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• pp.253-261
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• 2016

A variety of methods for detecting the location of an underground water pipeline are being used across the world; the current main methods used in South Korea, however, have the problems of low precision and efficiency and the limitations in actual application. On this, this study developed locator capable of detecting the location of a water pipe by the use of an IMU sensor, and technology for using the extended karman filter to correct error in location detection and to plot the location on the coordinate system. This study carried out a tract test and a road test as basic experiments to measure the performance of the developed technology and equipment. As a result of the straight line, circular and ellipse track tests, the 1750 IMU sensor showed the average error of 0.08-0.11%; and thus it was found that the developed locator can detect a location precisely. As a result of the 859.6-m road test, it was found that the error was 0.31 m in case the moving rate of the sensor was 0.3-0.6 m/s; and thus it was judged that the equipment developed by this study can be applied to long-distance water pipes of over 1 km sufficiently. It is planned to evaluate its field applicability in the future through an actual pipe network pilot test, and it is expected that locator capable of detecting the location of a water pipe more precisely will be developed through research for the enhancement of accuracy in the algorithm of location detection.

• Journal of Biosystems Engineering
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• 제37권2호
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• pp.113-121
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• 2012

Purpose: Particle separation in solution is one of important process in a unit operation as well as in an extract preparation for biosensors. Contrary to centrifuge-type of mesh-type filter, using an ultrasonic standing wave make the filtering process continuous and free from maintenance. It is needed to investigate the characteristics of particle movement in the ultrasonic standing wave field. Methods: Through the computer simulation the effects of major design and driving parameters on the alignment characteristics of particles were investigated, and a cylindrical chamber with up-stream flow type was devised using two circular-shape PZTs on both sides of the chamber, one for transmitting ultrasonic wave and the other for just reflecting it. Then, the system performance was experimentally investigated as well. Results: The speed of a particle to reach pressure-node plane increased as the acoustic pressure and size of particle increased. The maximum allowable up-stream flow rate could be calculated as well. As expected, exact numbers of pressure-node planes were well formed at specific locations according to the wavelength of ultrasonic wave. As the driving frequency of PZT got close to its resonance frequency, the bands of particles were observed clearer, which meant the particles were trapped into narrower space. Higher excitation voltages to the PZT produced a greater acoustic force with which to trap particles in the pressure-node planes, so that the particles gathered could move upwards without disturbing their alignments even at a higher inlet flow rate. Conclusions: This research showed the feasibility of particle separation in solution in the continuous way by an ultrasonic standing wave. Further study is needed to develop a device to collect or harvest those separated particles.