• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.43 no.11
• /
• pp.943-951
• /
• 2015

Inertial sensors are important components of navigation system whose performance and reliability can be improved by specific sensor arrangement configuration. For the reliability of the system, Fault Detection and Isolation (FDI) is conducted by comparing each signal of arranged sensors and many arrangement configuration were suggested to optimize FDI performance of the system. In this paper, multiple conic configuration is suggested with optimal navigation condition and its FDI performance is analyzed by established Figure Of Merit (FOM) under the condition for navigation optimality. From FOM comparison, the multiple conic configuration is superior to former one in point of FDI.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.8
• /
• pp.855-860
• /
• 2011

We numerically simulated a dissolved air flotation (DAF) tank to predict the performance of the pilot facility. The flow was assumed to be two-dimensional and two-phase. The velocity distributions in the separation zones of differently shaped DAFs were compared to find the effect of the shape on the performance. The results showed that the typical flow pattern that appeared in a well-designed DAF-tank was generated in the separation zone of the base model. This flow pattern could be maintained while the baffle height was sufficiently tall regardless of the other geometric parameters. However, the baffle height and angle, the contact zone width, and the perforated plate affected the uniformity of the downward flow in the separation zone. Except for the baffle height, the base model used in this study showed a better uniformity of downward flow than did other models with different geometric parameters.

• Journal of Energy Engineering
• /
• v.11 no.3
• /
• pp.276-282
• /
• 2002

The process of energy separation in a low Pressure vortex tube with compressed air as a work-ing medium is studied in detail. Experimental data of the temperature of the cold and hot air leaving the vortex tube are presented. The variation of the maximum wall temperature along the inner surface of the vortex tube and the temperature distribution in a vortex tube provide useful information about the location of the stagnation point of the flow field at the axis of the vortex tube. Analysis of the results enabled to find the optimum length of the vortex tube, the optimum shape of the Throttle and the usefulness of the Sleeve. In this study Outer tube is used for the exhaust application. The hot gas flow is turned 180$^{\circ}$and passes the out-side of the vortex tube a second time heating it. From this geometric setup of a vortex tube He effects of energy separation and the prediction of the ignition of Diesel Soot is presented by experimental data.

• Journal of Korea Water Resources Association
• /
• v.48 no.8
• /
• pp.625-634
• /
• 2015

The diverse patterns of separation zone according to the marked bed discordance by dredging at confluence in addition to the confluence angle of tributary and discharge ratio between tributary and main channels have been analyzed by CCHE2D model simulation. The separation zone is defined by inside of zero velocity boundary at down-stream of confluence. The separation zone dose not formed at the $30^{\circ}$ of confluence angle of tributary. The size of separation zone increases as the discharge ratio and confluence angle increase in general. The separation zone decreases as the dredging depth increases which shows the relative momentum reduction compared by the flow volume increasing by dredging at confluence. The contraction factor with the variation of confluence angle and discharge ratio has been investigated and confirmed the corresponding conveyance decreasing results in backwater effect. The regression equation of shape factor with confluence angle and discharge and dredging depth ratios has been suggested.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.10b
• /
• pp.255-256
• /
• 2003

열가소성 폴리우레탄 공중합체는 가역적 변형을 갖는 soft segment와 물리적 가교역할을 하는 hard segment로 이루어져 있으며, 이들 두 segment domain의 상분리에 의하여 우수한 탄성효과를 발휘할 수 있으며 또한 적당한 구조제어에 의하여 형상기억효과를 나타내게 할 수 있다. 본 연구자들은 최근 형상기억 폴리우레탄 제조에 있어 soft segment의 배열을 달리함으로써 보다 우수한 역학적 성질을 갖는 시료를 얻을 수 있음을 보고하였다. (중략)

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2003.11a
• /
• pp.110-110
• /
• 2003

제올라이트는 다양한 유기질 분리의 촉매제 및 광학, 화학 센서, 기체 분리 등의 고기능 소재로서 크게 주목받고 있으며, 그 중 MFI type(ZSM-5, Silicalite-1) 제올라이트는 주로 석유화학공정에 주로 이용되고 있고, 분리막으로서 이산화탄소의 분리/회수 및 물/유기 혼합물의 분리 등에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 분리막 제조에 유리할 것으로 판단되어지는 적합한 크기와 형상을 갖춘 나노크기의 제올라이트 분말을 수열합성법과 마이크로웨이브 합성법을 이용하여 합성하였으며, 위의 조건으로 다공질 알루미나 지지 체 위에서 알루미나/제올라이트 분리막 제조를 하는데 성공하였다. 또 한 다양한 조건(시간, 온도, 조성)에 따른 막의 두께변화와 균열발생정도를 관찰한 결과 합성시간, 건조온도에 따라서 같은 조건의 분리막 사이에서도 현격한 차이가 나타남을 알 수 있었다. 얻어진 MFI type제올라이트 분말과 분리막은 XRD, SEM, BET, TGA, FT-IR등의 분석수단을 이용하여 물성평가를 실시하였다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2003.04a
• /
• pp.398-404
• /
• 2003

Most previous researches for the hybrid composite materials such as FRMLs(Al/AFRP, Al/GFRP) have evaluated the fatigue delamination behavior using the traditional fracture mechanism. However, most previous researches have not generally been firmed yet. Because delamination growth behavior in hybrid composite should be consider delamination growth rate, $dA_D$/da using the delamination shape factors, fs instead of traditional fracture mechanic parameters. The major purpose of this study was to evaluate the relationship between delamination shape factor, fs and delamination growth rate, $dA_D$ . And a propose parameter on the delamination aspect ratio, b/a. The details of the study are as follow : 1) Relationship between crack length, a and delamination width,b. 2) Relationship between delamination aspect ration, b/a and delamination area rate,($(A_D)_{N}(A_D)_{ALL}$. 3) Variation of delamination growth rate, $dA_D/da$ was attendant on delamination shape factors, $fs_1$, $fs_2$, $fs_3$. The test results indicated the delamination growth rate depends on delamination shape factors.

• Proceedings of the KSEEG Conference
• /
• 2000.04a
• /
• pp.30-31
• /
• 2000

• Journal of Dairy Science and Biotechnology
• /
• v.12 no.1
• /
• pp.20-27
• /
• 1994

건강한 성인의 분변으로 부터 호기적인 평판배지에서의 생육이 가능한 비피더스균을 선별 분리하는 조건과 상기 분리주의 특성을 규명한 결과는 다음과 같다. 1.5%의 탈섬유소 말혈액을 첨가한 BLB Agar Medium에 인체 분변을 호기적으로 표면 배양하여 내산소성 비피더스균 변이주를 분리하였다. 상기 분리주는 BLB Agar Medium 평판배지에 호기적으로 배양 했을때 $1.1\;{\times}\;10^9$ cfu/ml 이상의 높은 균수를 유지하였다. 2. 상기의 내산소성 비피더스균 분리주를 BLB Agar Medium 에 호기적으로 배양했을때 0.5mm, 연유갈색, 원형, 융기상의 윤택한 집락을 형성하였으며 현미경 검경 결과 Y 자형 분지상과 V자형 만곡간균상, 팽윤상 등의 전형적인 비피더스균 형상으로 나타냈다. 3. 탄수화물 발표실험 결과 상기의 내산소성 비피더스균 분리주는 Bif. adolescentis 로 동정되었으며 F6PPK GKA효소 활성 함께 매우 높은 ${\alpha}$-Galactosidase, $\beta$ - Galactosidase, ${\alpha}$-Galactosidase, 효소 활성을 나타냈다. 한편 아무것도 첨가하지 않은 순수한 우유 중에서의 발효성 및 호기적인 생육능이 매우 양호하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 1996.11a
• /
• pp.147-153
• /
• 1996

발사관의 밀폐 및 분리성능을 위해 앞, 뒤 덮개의 재질을 내열성이 높고, 수분흡수성이 낮은 Noryl Plastic 재질로 선정하여 기계적 물성을 확인하였으며 덮개의 형상설계를 하였다. 유한요소 구조해석을 수행하여 분포하중 및 집중하중에 의한 응력상태를 고찰하고 분리성능을 검증하기 위해 공압 및 유도탄 충돌시험을 수행하였다. 이상의 과정를 통하여 개발된 덮개는 여러 가지 체계요구조건을 만족시켜 주는 것을 알 수 있다.