• 한국어류학회지
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• 제28권4호
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• pp.223-228
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• 2016

한국산 대륙송사리 Oryzias sinensis의 후각기관을 실체현미경과 광학현미경을 이용하여 해부 및 조직 화학적 특징들을 조사하였다. 전체적 구조에서 후각기관은 두부의 주둥이 위에 한 쌍으로 존재하였으며 다소 떨어져있는 전비공과 후비공, 한 개의 비강, 한 개의 비낭으로 구성되었다. 비강내 상피는 감각상피와 비감각상피층으로 구분되었다. 감각상피는 후감각세포, 지지세포, 기저세포 그리고 공포들로 구성되었다. 비감각상피는 층상상피 세포, 산성과 중성 점액세포들로 구성되었다. 비낭의 상피층은 층상상피세포와 배상세포들로 구성되었다. 결과적으로 이러한 대륙송사리의 후각기관의 해부 및 조직화학적 특징들은 농경지에서의 정체되고 오염되어있는 수환경을 반영하는 것으로 사료된다.

• 건축역사연구
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• 제29권1호
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• pp.21-37
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• 2020

The purpose of this paper is to reconstruct the original floor plan and wall design of Seokbulsa Grotto in Kyungju; commonly known as 'Seokguram'. The paper presents an array of dimensional studies of the existing Seokguram to examine its architectural form, and infers the original floor plan and wall design of Seokbulsa Grotto. Seokbulsa Grotto is designed as a system of 'coherent modules' and was constructed using the dry stone method, which interlocks large stone modules into a whole that becomes the load-bearing structure itself. The design principles governing Seokbulsa Grotto are the spatial axis of symmetry, modular coordination, and the layout grid of a quarter Tang-Ruler(TR: 唐尺). Dimensional studies were conducted with these governing principles in mind and concludes the following about the original floor plan design. In the main chamber, Ansang-stone's radius is 12 TR, and Flagstone's radius is 12¼ TR. In the front chamber, the width between the two Ansang-stones facing each other is 22 TR and the longitudinal space depth is 12 TR, while the width between the two Flagstones facing each other is 22½ TR and Flagstone's depth is 12 TR. In the passageway, the width between the two Ansang-stones facing each other is 11½ TR and longitudinal space depth is 9 TR, while the width between the two Flagstones facing each other is 12 TR and Flagstone's depth is 7¾ TR. The distance from the center to the entrance line of the main chamber is 10½ TR. Therefore, the total longitudinal length of the Grotto is 43½ TR at the level of the Ansang-stones, and 44 TR at the level of the Flagstones.

• 한국해양공학회지
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• 제28권3호
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• pp.227-235
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• 2014

Using a 3-D numerical scheme (LES-WASS-3D) that considered wave-structure-sandy seabed interactions in a 3-D wave field, we analyzed the wave reflection and hydraulic characteristics inside a slit caisson with two chambers in a 3-D oblique wave field. To verify the 3-D numerical analysis method suggested in this study, we compared the numerical results with existing experimental results and found good agreement. The numerical analysis revealed that a standing wave field is generated on the front side of the slit caisson due to the effect of wave reflection. For incident waves propagating perpendicular to the slit caisson, the nodes and anti-nodes of the standing wave are apparent and symmetrical. However, in an oblique wave field, as the incident wave angle decreases, the nodes and anti-nodes of the standing wave become ambiguous and unsymmetrical. It was also found that the wave reflection coefficient decreases as the incident wave angle decreases. It can be pointed out that as the incident wave angle decreases, the turbulent intensity in the chamber increases. Thereby, the increased wave energy dissipation by the increased turbulent intensity reduces the rate of wave reflection. In addition, a strong turbulent intensity generally occurs in the first chamber.

• 반도체디스플레이기술학회지
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• 제23권1호
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• pp.92-96
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• 2024

The application of the technology for forming Al₂O₃ thin films using ALD(atomic layer deposition) method is rapidly increasing in the semiconductor and display fields. In order to increase the efficiency of the ALD process in a mass production line, metallic by-products generated from the ALD process chamber must be effectively collected. By collecting by-products flowing out of the chamber with a cold trap device before they go to the vacuum pump, damage to the vacuum pump can be prevented and the work room can be maintained stably, resulting in increased process flow rate. In this study, a cold trap was installed between the ALD process chamber and the dry pump to measure and analyze by-products generated during the Al₂O₃ thin film deposition process. As a result, it was confirmed that Al and O elements were discharged, and the collection forms were two types: bulk and powder. And the binding energy peaked at 73.7 ~ 74.3 eV, the binding energy of Al 2p, and 530.7 eV, the binding energy of O 1s, indicating that the binding structure was Al-O.

• International Journal of Aeronautical and Space Sciences
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• 제13권2호
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• pp.221-228
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• 2012

An active compensation method for the deformation of composite structures using additional controllable metal parts is proposed, and its feasibility is experimentally investigated in a simulated space environment. Composite specimens are tested in a vacuum chamber, which is able to maintain pressure on the order of 10-3 torr and interior temperature in the range of ${\pm}30^{\circ}C$. The displacement-measuring interferometer system, which consists of a heterodyne HeNe laser and an interferometer, is used to measure the displacement of the whole structure. Meanwhile, the strain of the composite part and temperature of both parts are measured by fiber Bragg grating sensors and thermistors, respectively. The displacement of the composite structure is maintained within a tolerance of ${\pm}1{\mu}m$ by controlling the elongation of the metal part, which is bonded to the end of the composite part. Also, the possibility of fiber Bragg grating sensors as control input sensors is successfully demonstrated using a proper corrective factor based on the specimen temperature gradient data.

• 한국군사과학기술학회지
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• 제21권4호
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• pp.422-428
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• 2018

Increase in use of lightweight structures, coupled with the increased acoustic loads resulting from larger and longer range guided missiles, has made missile more susceptible to failures caused by acoustic loads. Thus, accurate prediction of acoustic environment and the response is becoming ever more important for mission success. In this paper, the acoustic response of a sandwich composite skin structure to diffuse acoustic excitation is predicted over a broad frequency range. For the low frequency acoustic analysis, coupled FE-BEM method is used where the structure is modeled using FEM and the interior and exterior fluid is modeled using BEM. For the high frequency region, statistical energy analysis is applied. The predicted acoustic level inside the structure is compared with the result from acoustic test conducted in reverberation chamber, which shows very good agreement.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.185-185
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• 2009

Micropump is very useful component in micro/nano fluidics and bioMEMS applications. Using the flexural vibration mode of PZT bar, a piezopump is successfully made. The PZT bar is polarized with thickness direction. The proposed structure for the piezo-pump consists of an input and an output port, piezoelectric ceramic actuator, actuator support, diaphragm. The traveling flexural wave along the bar is obtained by dividing two standing waves which are temporally and spatially phase shifted by 90 degrees from each other. Fluid is drawn into a forming chamber, eventually the forming chamber closes trapping the fluid therein. The finite elements analysis on the proposed pump model is carried out to verify its operation principle and design by the commercial FEM software. Components of piezopump were made, assembled, and tested to validate the concepts of the proposed pump and confirm the simulation results. The performance of the proposed piezopump the highest pressure level of 83.4kHz.

• 한국유체기계학회 논문집
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• 제12권3호
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• pp.31-37
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• 2009

This paper presents a implantable intrathecal drug infusion pump for pain control in cancer patients. This device consists of micropump module, drug reservoir module and control module. The micropump module using cam-follower mechanism composed of small-sized four cams and four followers. Each followers is driven by a cam and liquid is discharged by a sequential reciprocal motion of the followers. The advantage of this structure is that it allows the pump to be clean and valveless. The drug reservoir module composed of drug chamber, gas chamber and diaphragm. The control module composed of battery, wireless communication unit and controller. To design a small-sized, low power pump some analysis were performed to determine the design parameters. To verify the feasibility of the experiment, a prototype was manufactured and its operating characteristics were investigated. Experimental results were in accordance with the expected results obtained from analysis.

• 한국전산유체공학회지
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• 제7권3호
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• pp.9-16
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• 2002

Most of modem aerospace gas turbines must be operated at a gas temperature which is several hundreds of degrees higher than the melting temperatures of the materials used in their construction. Complicated cooling schemes need to be employed in the combustor walls and in the high pressure turbine stages. Internal passages are cast or machined into the hot sections of aero-gas turbine engines and air from the compressor is used for cooling. In many cases, the cooling system is engineered to utilize jets of high velocity air, which impinge on the internal surfaces of the components. They are categorized as 'Impinging Cooling Method' and 'Vortex Cooling Method'. Specially, research of new cooling system(Vortex Cooling Method) that overcomes inefficiency of film cooling and limitation of space. The focus of new cooling system that improves greatly cooling efficiency using less amount of cooling air on surface heat transfer elevation. Therefore, in this study, a numerical analysis has been peformed for characteristics of flow and heat transfer in the swirl chamber and compared with the flow measurements by LDV. Especially, for understanding high heat transfer efficiency in the vicinity of wall, we considered flow structure, vortex mechanism and heat transfer characteristics with variation of the Reynolds number.

• Applied Microscopy
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• 제48권1호
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• pp.11-16
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• 2018

For Odontamblyopus lacepedii with small and turbid eyes, the gross structure and histology of the olfactory organ, which is important for its survival and protection of the receptor neuron in estuarial environment and its ecological habit, was investigated using a stereo, light and scanning electron microscopes. Externally, the paired olfactory organs with two nostrils are located identically on each side of the snout. These nostrils are positioned at the anterior tip of the upper lip (anterior nostril) and just below eyes covered with the epidermis (posterior nostril). Internally, this is built of an elongated olfactory chamber and two accessory nasal sacs. In histology, the olfactory chamber is elliptical in shape, and lined by the sensory epithelium and the non-sensory epithelium. The sensory epithelium of a pseudostratified layer consists of olfactory receptor neurons, supporting cells, basal cells and lymphatic cells. The non-sensory epithelium of a stratified layer has swollen stratified epithelial cells and mucous cells with acidic and neutral sulfomucin. From these results, we confirmed the olfactory organ of O. lacepedii is adapted to its ecological habit as well as its habitat with burrows at the muddy field with standing and murky waters.