Infrared(IR) heating has many advantages, such as energy efficiency, reduced heating time, cleanliness, equipment compactness, high drying rate and easy automation. These features of IR heating provide widely industrial applications, such as surface heat treatment in semiconductor fabrication, thermoforming of polymers, drying and disinfection of food products, heating to metal forging, and drying of wet materials. In this study, the characteristics of a protected gold mirror were examined by spectrophotometer and the lifetime of the coating layers were evaluated by a cross-cutting method and salt spray test. The effects of manufacturing conditions on the protected gold mirror were seen and remedies for these effects were noted in order to improve the properties of the protected gold mirror in the drying process. The reflectance and lifetime of the protected gold mirror was influenced by manufacturing conditions, such as surface roughness and forming conditions of the anti-oxide layer, the adhesion layer, the reflecting layer and the protection layer. The results of this study showed that the protected gold mirror manufactured using a buffing method for pre-treatment resulted in the most effective reflectance. In addition, Al2O3 coating on an Al substrate as an anti-oxide layer was more effective than the anodizing process in the test of reflectance. Furthermore, the protected gold mirror manufactured by layers forming of various materials resulted in the most effective reflectance and lifetime when coated with Al2O3 as the anti-oxide layer, coated Cr as the adhesion layer, and coated MgF2 as the protection layer.

Beam bracing is applied to prevent the relative displacement of the top and bottom flanges or to effectively control the twisting of the section, and the lateral stability of the beams are provided by lateral bracing, torsional bracing or a combination of both. Modular steel I-girders are laterally interconnected by torsional bracings that are installed to increase the resistance to lateral torsional buckling. In this paper, numerical parametric study was carried out by varying the crossbeam web height to examine the effects of the web torsional stiffness. Three-dimensional finite-element analysis using the commercial finite element software ABAQUS was obtained for the parametric numerical analyses of a series of feasible two-girder models, and the failure mode, lateral-torsional buckling strength and the moment-displacement behavior of the main girders was determined.

A parametric study was carried out to gain an insight about structural performances considering abnormal behavior effects in high strength steel pipe strut system. Six load cases were considered as undesirable deflections of strut structures, which are basic load combination, excessive excavation situations, impact loading effects, additional overburden loads, load combinations, and 50% reduction of strut length. Subsequent simulation results present various influences of parameters on structural performances of the strut system. Based on the results, we propose methods to prevent unusual behaviors of pipe-type strut structures made of high strength steels.

Alane(aluminum trihydride, AlH3)으로 명명되는 고에너지 물질인 삼수소알루미늄은 수소저장 물질로서 뿐만 아니라 우주항공분야의 고체 추진제나 방위산업의 화약제조용으로도 사용될 수 있다. 본 연구는 습식공정을 통하여 합성하고, 에테르를 세밀하게 분리하는 결정화 공정을 통하여 최종 수소화물을 추출하였다. 결정화 공정에서 삼수소알루미늄-에테레이트(AlH3·(C2H5)2O)가 alane으로 상변이하면서 입자가 성장하고, 85℃에서 2 시간의 결정화 시간이 이루어졌을 때 가장 안정된 결정상이 나타나는 모습을 확인하였다. 최종적으로 추출된 고체상 삼수소알루미늄은 막대모양의 γ-형태가 가장 많은 양을 차지하는 것으로 나타났으며, 크기는 50-100 μm 수준이었다

The purpose of this study was to analyze some parameters’ effects on buckling behavior of Sinusoidal Corrugated Web using finite element analysis program. Studying buckling behavior is one of the most important things to design sinusoidal corrugated web girders and predict the shear performance. In this paper, Four parameters of Sinusoidal Corrugated Web, which are thickness( ), height( ), wave height( ) and wave length( ), were selected for buckling behavior analysis. Via buckling analysis, it is shown that  ,  and  have influence on shear buckling stress, Initial stiffness and reduced strength after buckling.

지면반사도 정보는 열평형 및 환경/기후 모니터링에 중요하다. 본 연구에서는 정지궤도위성의 Geostationary Environment Monitoring Spectrometer (GEMS) 관측에서 300-500 nm 파장 영역의 지면반사도 산출 시에 오차 유발 요 소에 대한 민감도를 조사하였다. 장차 GEMS 지면반사도 산출 시에 오차 분석을 위하여 극궤도 위성의 MODerate resolution Imaging Spectroradiometer (MODIS; 공간 해상도 1 km×1 km) 자료 및 Ozone Mapping Instrument (OMI; 12 km×24 km) 자료 그리고 복사전달모델 수치실험도 분석에 사용하였다. 본 연구에서 오차 유발 요소는 구름, 레일리 산란, 에어로졸, 오존 그리고 지면 특성이다. GEMS 저해상도(8 km×7 km)에서의 구름 탐지율은 MODIS 대비 약 79% 이었으나, GEMS 화소의 운량이 40% 이하에서는 상대적으로 낮았다. 이러한 경향은 구름 이외의 다른 효과(에어로졸, 지면 특성)로 인하여 주로 발생하였다. RGB 영상과 복사전달모델 계산을 기초로 조사된 레일리 산란 효과는 육지에 비하여 해양 지역에서 뚜렷하였다. 지면반사도가 0.2보다 작은 경우에 위성관측 대기상단 반사도는 에어로졸 양에 비례 하였으나, 0.2보다 큰 경우에는 그 반대 경향을 보였다. 또한 에어로졸 양에 의한 지면반사도 산출 오차는 자외선 영역 에서 파장에 따라 급격하게 증가하였으나, 가시광선에서는 일정하거나 다소 감소하였다. 오존 흡수는 자외선 영역(328- 354 nm) 중 328 nm에서 가장 크게 나타났다. 지면반사도가 0.15인 육지 경우에 음의 오존전량 아노말리(-100 DU)로 인한 지면반사도 산출 오차는 +0.1이었다. 본 연구는 GEMS 위성관측을 이용한 지면반사도 원격탐사의 정확도를 높이 는데 기여할 수 있다.

This study aims to investigate the physicochemical properties of extruded Biji. As the extrusion process variables, the barrel temperature and the moisture content were adjusted at barrel temperatures of 120, 140, and 160°C and 35, 45% respectively. L-value (lightness) increased as the moisture content and barrel temperature increased from 35% to 45% and 120°C to 160°C. In contrast, decreasing a-value and b-value resulted in increasing moisture content and barrel temperature. Total sugar, DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging activity, ABTS (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)) radical scavenging activity, and total phenolic compound were increased by the extrusion process. The water solubility index (WSI) and dietary fiber of the extruded biji decreased to 3.9% and 592.6 mg/g compared to the non-extruded biji of 12.3% and 592.6 mg/g. According to the result of this study, the extruded biji could be used in various kinds of food processing, and future study is needed to find the optimum condition of the extrusion.

광도와 온도 같은 환경 요인에 의해 광합성 속도가 변화하기도 하며, 생육 시기에 따른 광합성 효율의 변화가 수반되기도 한다. 본 연구에서는 흑로메인 상추(Lactuca sativa L., Asia Heuk romaine)를 이용하여 광도와 온도, 생육 시기에 따른 군락 광합성 속도를 표현하는 두 모델을 구축하고 비교하는 것을 목표로 하였다. 군락 광합성은 정식 후 4, 7, 14, 21, 28 일차 상추를 아크릴 챔버(1.0 × 0.8 × 0.5m)에 넣어 측정하였으며, 이 때 챔버 내부의 온도는 19oC에서 28oC까지 변화시켰고 광원은 LED를 이용하여 50에서 500μmol·m-2·s-1까지 변화시키며 실험하였다. 챔버 내부의 초기 이산화탄소 농도는 2,000μmol·mol-1로 설정하였으며, 시간에 따른 이산화탄소 농도의 변화율을 이용하여 군락 광합성 속도를 계산하였다. 각 환경요인을 표현하는 3개 식을 곱하여 만든 단순곱 모델을 구성하였다. 이와 동시에 온도와 생육 시기에 따라 변화하는 광화학 이용효율과 카르복실화 컨덕 턴스, 호흡에 의한 이산화탄소 발생 속도를 포함하는 수정된 직각쌍곡선 모델을 구성하여 단순곱 모델과 비교하였다. 검증 결과 단순곱 모델은 0.849의 R2 값을 나타내었으며, 수정된 직각쌍곡선 모델은 0.861의 R2 값을 나타내었다. 수정된 직각쌍곡선 모델이 단순곱 모델에 비해 환경 요인(광도, 온도), 생육 요인(생육 시기)에 따른 군락 광합성 속도를 표현하는데 더욱 적합한 모델인 것으로 판단하였다.

시각 정보 중 색채는 인간의 감성을 일으키는 중요한 요소이다. 그러므로 감성을 유발하거나 예측하기 위해서 색의 효과를 확인하는 것은 중요하다. 본 연구는 색채에 따른 감성의 차이를 확인하고자 색채 자극에 따른 심혈관 반응을 측정하였다. 색채 자극은 Red, Green, Blue, Cyan, Mangenta, Yellow의 6가지 색상으로 구성된 이미지들을 사용하였다. 실험에 참여한 대학생 26명(남자 13명)은 Electrocardiogram (ECG) 센서를 착용하고 모니터에 제시된 각 자극을 본 후 주관감성을 평가하였다. 색채 자극에 따른 심혈관 반응 데이터는 Kruskal-wallis 검정과 Mann-Whitney 검정을 수행하여 분석하였다. 그 결과 Coherence ratio가 Green과 Magenta (p=.004), Red (p=.006), Yellow (p=.004) 색상에서 유의한 차이가 있었다. 본 연구는 색상에 따른 유효한 심혈관 반응 변수와 감성의 차이를 확인하였으며 이러한 차이는 쾌-불쾌의 감성과 관련이 있었다. 본 연구는 녹색이 쾌의 감성을 유발하고 적색이 불쾌의 감성을 유발할 수 있음을 보인 실증적인 연구로써 의의가 있다.

SiAlON-based ceramics are some of the most typical ceramic materials used as cutting tools for HRSA(Heat Resistant Super-Alloys). SiAlON can be fabricated using ceramic processing, such as mixing, granulation, compaction, and sintering. Spray drying is a widely-used method for producing a granular powder of controlled morphology and size with flowability. In this study, we report a systematic investigation aimed at optimizing spherical granule morphology by controlling spray-drying parameters such as gas flow and feed rate. Before spray drying, the viscosities of the raw material slurries were also optimized with the amount of dispersant added.

This study investigates the quality characteristics of dough and bread added with 6% chestnut shell powder and extruded chestnut shell powder at various conditions. As extrusion process variables, melt temperature (110°C, 130°C, 150°C) and moisture (25% and 30%) were controlled. Total dietary fiber content was slightly increased in extruded chestnut shell powder group. In the farinogram, absorption was significantly increased in the group of 25% moisture content and 30% moisture content (p<0.05). After 2 hours and 3 hours, the leavening heights of dough for control showed a similar tendency to that of dough with extruded chestnut shell at a melt temperature 150°C and with moisture content of 25% and 30%. Specific volume was the highest at a control of 3.74±0.08 cc/g and extruded chestnut shell powder group was slightly higher than the chestnut shell powder group. Firmness after 1 day on control of 107.42±14.52 g was similar to that of the bread with extruded chestnut shell at a temperature of 150°C and moisture content of 25% for 113.33±6.17 g. In conclusion, the extrusion-cooking of chestnut shell powder improved the quality characteristics of dough and bread. The optimum combinations of conditions in tested range were melt temperature at 150°C and moisture content at 25%, and melt temperature at 130°C and moisture content at 30%.

The coupled shear wall system with coupling beams is an efficient structural system for high-rise buildings because it can provide excellent ductility and energy dissipation to the buildings. The objective of this study is to simulate the hysteretic behavior of diagonally reinforced concrete coupling beams including pinching and cyclic deteriorations in strength and stiffness using a numerical model. For this purpose, coupling beams are modeled with an elastic beam element and plastic spring element placed at the beam ends. Parameters for the analytical model was calibrated based on the test results of 6 specimens for diagonally reinforced concrete coupling beams. The analytical model with calibrated model parameters is verified by comparing the hysteretic curves obtained from analysis and experimental tests.

The damping effects on stabilities of a simply supported pipe conveying fluid is investigated using the complexification-averaging method. The flow is assumed to vary harmonically about a mean speed. Unstable conditions of a piping system included with the viscous and material damping are analytically obtained for primary, secondary and combination parametric resonances. The primary and secondary resonances occur when the frequency of flow fluctuation is close to one and two times the natural frequency. And when this frequency is close to the sum of any two natural frequencies, combination resonances occur. The effects of damping parameters on the regions of three parametric resonances are discussed.

In order to identify the antecedents of internet purchasing intention toward fashion items, this study examines shopping-related variables as both direct antecedents of internet purchasing intention, and as indirect antecedents of internet purchasing intention through online-related variables. Impulse buying and market mavenism were considered as shopping-related variables, whilst online interaction readiness and online consumer procrastination were considered as online-related variables. It was hypothesized that impulse buying and market mavenism not only directly influence purchasing intention toward fashion items, but also indirectly influence it through online interaction readiness and online consumer procrastination. Data were gathered by surveying university students in Seoul using convenience sampling. A total of 286 questionnaires were used in the statistical analysis. SPSS was used for exploratory factor analysis, and AMOS was used for confirmatory factor analysis and path analysis. The factor analysis of market mavenism, impulse buying, and online consumer procrastination revealed one dimension, whilst the factor analysis of online interaction readiness revealed two dimensions: ‘online relationship’ and ‘internet role.’ Tests of the hypothesized path proved that impulse buying indirectly influences internet shopping intention only through online consumer procrastination, whereas market mavenism influences internet shopping intention indirectly through both online interaction readiness and online consumer procrastination. The results will be useful for Internet shopping mall marketers and for future study.

본 논문에서는 원통형 혼합기를 대상으로 블레이드의 각도, 길이, 개수 및 블레이드와 탱크 바닥과의 간극을 설계변수로 선정하고, 각각의 설계변수가 혼합성능에 미치는 영향을 분석하였다. 이산요소법을 이용하여 임펠러 회전에 의한 고체 입자 의 혼합공정을 해석하였으며, 혼합지수를 도입하여 혼합성능을 정량적으로 평가하였다. 다양한 설계변수의 조합을 고려한 실험계획법으로 설계변수의 주효과와 교호작용을 분석함으로써, 블레이드 각도가 입자의 혼합성능에 가장 지배적인 영향을 미치며 간극의 영향은 상대적으로 작다는 결론을 도출할 수 있었다. 또한 가장 우수한 혼합성능을 보이는 설계변수의 조합 을 제시하였다.

In this study, we investigate the mechanical and metallurgical properties of the gas metal arc welding. According to flux cored arc welding parameters during welding ATOS80, improving the working conditions of the welding industry to use high strength steel ATOS80 we propose to. Weld test is the tensile strength, yield strength, elongation, hardness, brittleness, such as macro-structure check of the mechanical properties and the weld, the microstructure inspection, defects of the weld subjected to radio-graphic inspection and tissue after welding the test pieces according to the condition variable comparative analysis was investigated by the state.

This study was carried out to investigate the optimum condition of a friction stir welding process for a joint of AA2219-T87 and AA2195-T8 dissimilar aluminum alloys. These alloys are known to have good cryogenic properties, and as such to be suitable for use in fuel tanks of space vehicles. The welding parameters include the travelling speed, rotation speed and rotation direction of the tool. The experiment was conducted under conditions in which the travelling speed of the tool was 120-300 mm/min and the rotation speed of the tool was 400-800 rpm. To investigate the effect of the rotation direction of the tool, the joining was performed by switching the positions of the two dissimilar alloys. After welding, the microstructure was observed and the micro-hardness were measured; non-destructive evaluation was carried out to perform tensile tests on defect-free specimens. The result was that the microstructure of the weld joint underwent dynamic recrystallization due to sufficient deformation and frictional heat. The travelling speed of the tool had little effect on the properties of the joint, but the properties of the joint varied with the rotation speed of the tool. The conditions for the best joining properties were 600 rpm and 180-240 mm/min when the AA2219-T8 alloy was on the retreating side(RS).

According to the structure, solenoid valve can be categorized as spool valve or poppet valve. While various research on spool valve which has simple structure and fine susceptibility to contamination has been conducted, poppet valve which has less susceptibility to contamination and advantage in a long time operation still need much research because of its complicated structure. In order to design the poppet valve, various parameters such as the diameter of the poppet, the angle of the poppet, the diameter of the disk, the spring stiffness, the spring preload and flow path structure should be considered. Conventional studies on poppet valve usually take only one design parameters and did not much focused on the effect of the parameters on flow characteristics. In this paper, the change of the flow characteristics according to the design parameters of the poppet valve for 3/2Way solenoid valve is analyzed. The previous studies and the results of initial model analysis was referred for the selection of the design parameters. The effects of design parameters on maximum pressure, minimum pressure, and pressure drop was examined using analysis of means(ANOM).

The cyclic behavior of braces is complex due to their asymmetric properties in tension and compression. For accurately simulating the cyclic curves of braces, it is important to predict the major parameters such as cyclic brace growth, cyclic buckling load, incidence local buckling and fracture with good precision. For a given brace, the most accurate values of these parameters can be estimated throughout experiments. However, it is almost impossible to conduct experiments whenever an analytical model has to be established for many braces in building structures due to enormous cost and time. For avoid such difficulties, empirical equations for predicting constituent parameters are proposed from regression analyses based on test results of various braces. This study focuses on rectangular hollow structural section(HSS) steel braces, which have been popularly used in construction practice owing to its sectional efficiency.

The concrete wall panels are composed of various members such as studs, brackets, bolts and nuts, etc. Embedded studs in the concrete wall resist transferred lateral and horizontal load in the structure. The thickness of the concrete wall influences shear behavior of embedded studs. The finite element analysis was carried out with respect to the thickness of the concrete wall to investigate shear behavior of embedded studs. The numerical analysis results were compared with the experimental results and confirmed that The deformation of the stud anchor is reduced with an increase of the thickness of the concrete wall.