• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.02a
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• pp.329-334
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• 2003

배추의 포장상자를 예냉ㆍ저온유통에 적합한 구조로 개선하기 위하여 3-4포기용 골판지 상자를 T11형 표준 팔레트에 적재율이 96%이상 되게 제작하여 고습조건에서도 안전하게 배추를 보호할 수 있는 상자구조를 찾기 위한 수직압축강도시험과 냉각성능 및 예냉후 품질 변화에 대한 시험을 실시하였다. 가. 배추의 저온유통에 사용하는 골판지포장상자는 개공율을 5.4%로 하고, 포장상자 형태를 접음식 형태로 하는 것이 예냉속도 및 예냉균일도에서 유리하고, 저장후 수직압축강도에서는 브릿스박스에 비하여 낮게 나타났지만, 안전압축강도 이상의 압축강도를 나타내었고 제작단가도 저렴하였다. 나. 예냉 후 저장 중 품질변화는 배추 줄기의 절단력을 측정한 결과 개선된 포장상자에서 유통기한을 6-7일정도 연장시킬 수 있는 것으로 나타났다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.12
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• pp.1129-1134
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• 2007

Payload fairing protects satellites and electrical equipments from the external environment. Payload fairing is jettisoned before satellite separation. Assembly frame for the separation of payload fairing were assembled with shear bolts. The role of shear bolts is to support structural load during flight and they are cut by explosion of pyro. The assembly frame which is connected by shear bolts is separated after the cutting of shear bolts. In this paper, structural tests and analysis were done for the design of the shear bolt. Compression, bending and shear load apply to the hardware including assembly frame. Test results showed that design of the shear bolt satisfied both structural strength for the support of flight load and required low strength for the cutting of shear bolts.

• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.357-362
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• 2020

This study was conducted to investigate the effects of mushroom composition (0, 4, 8, and 12%) on the quality characteristics of an extruded meat analog. The meat analog blend was isolated soy protein, wheat gluten, and corn starch (50:40:10). The extrusion condition was set to 55% feed moisture, 170℃ barrel temperature, and 150 screw speed by high moisture extrusion using a twin-screw extruder equipped with a cooling die. The integrity index, hardness, cohesiveness, springiness, chewiness, and cutting strength of the meat analog increased with the increasing mushroom content, while its water holding capacity and nitrogen solubility index (NSI) decreased. The protein digestibility decreased with the increasing mushroom content, while the DPPH radical scavenging activity significantly increased. In conclusion, the incorporation of mushrooms into the investigated meat analog enhanced its texture and antioxidant level.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.3
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• pp.233-240
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• 2012

An experimental study to improve the impingement characteristics of the assist gas in laser cutting was carried out. For various assist-gas pressures, and locations and installation angles of the nozzle, the characteristics of the impingement of the jet from a supersonic rectangular nozzle were compared to those previously observed for typical circular nozzles. Schlieren flow visualizations and Pitot pressure measurements downstream of the kerf surface were utilized for this purpose. The present rectangular supersonic nozzle decreased the strength of the Mach disc occurring at the corner of the kerf surface, and thus, could weaken the separation of the assist gas on the kerf surface and increase the Pitot pressures downstream compared to conventional circular nozzles.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5748-5755
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• 2015

Scribing is cutting process to determine production amount and characteristic of LED chip. So it is an important process for fabrication of LED chip. Mechanical process and conventional scribing process with laser source has several problems such as thermal deformation, decreasing of material strength and limitation of cutting region. To solve these problems, internal laser scribing process that generates void in wafer and derives self-crack has been researched. However, studies of sapphire wafer cutting by internal laser scribing process for fabrication of LED chip are still insufficient. In this paper, cutting parameters were determined to apply internal laser scribing process for sapphire wafer for fabrication of LED chip. Then, foundation of cutting condition was established to set up internal laser scribing system through investigation of cutting characteristics by several experiments.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.4
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• pp.634-640
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• 1994

This study was investigate to see the effects of preparation methods on the physicochemical and sensory characteristics of cucumber preserved with salt. The preparation methods were brining the cucumbers in 10 % NaCl solution (boiled, method A), 205 NaCl solution (boiled, method B) an d20 % NaCl solution (cool to $25^{\circ}C$ after boiling, method C). The cucumber preserved with boiled solution and high salt concentration showed slow fermentation rate. The rate of salt penetration during brining of cucumber preserved with salt increased. The green value of cucumber preserved with salt by method B was lower than by method A and C. The cutting force of cucumber preserved with walt measured by texture analyzer showed a rapid increasing rate during initial brining periods. As a result of the sensory evaluation for cucumber preserved with salt, there were significant differences in most of characteristics between the samples at 5% level. The cucumber preserved with salt in boiled 10% NaCl solution (method A) showed the highest scores in most of the characteristics.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.11 no.1
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• pp.39-48
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• 1978

1) The decrease in strength of Raschel twines at Raschel joints is regarded to be due mainly to the frictional force between yarns and the unbalanced tensile distribution by the deformation of the joints. The rate of the decrease is about $13\%$ in lengthwise pull and 22 to $26\%$ in breadthwise pull. 2) The 3-course joint is less in deformation and stronger than the 2-course joint in all cases of pulls. 3) The variation of Raschel joint strength $T_R$ with the angle $\varphi$ between the adjacent bars is expressed as $T_R=T_{R0}-k\varphi$ where $T_{R0}$ is the strength at $\varphi=0^{\circ}$ and K is a constant. 4) The tensile strength ${\sigma}R$ and tile breaking energy $E_R$ of Raschel netting are given by $${\sigma}R=KN\;or\;${\sigma}R=T_RN$$ and $$E_R=AN$$ respectively, where N is the number of meshes at the pulling side, and K and A are constants. But the breaking energy of the netting is almost constant independent of tile variation of N. 5) The Raschel netting with some bars cut already breaks from tile joints of the bars next to the cut bars and its tensile strength, breaking energy, and breaking elongation decrease largily even if only one bar is in already cut state. 6) The tearing strength of Raschel netting is almost equal to the tensile strength of its single joint pulled by two bars. 7) The twisted joint is much more excellent in strength than the knot or the Raschel joint. The knot strength is 69 to $76\%$, and the Raschel joint strength is 71 to $74\%$ in lengthwise pull and 62 to $67\%$ in breadthwise pull, respectively, of the twisted joint strength.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.2
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• pp.94-100
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• 2010

Purpose: The purpose of this study was to compare the fracture strength of the zirconia ceramic crowns according to tooth position. Material and methods: After 10 metal dies were made for each group, the zirconia ceramic crowns were fabricated using CAD/CAM system ($Lava^{TM}$ All-Ceramic System) and each crown was cemented on each metal die with resin cement (Rely $X^{TM}$ Unicem). The cemented zirconia ceramic crowns mounted on the testing jig were inclined with 30 degrees to the long axis of the tooth and the universal testing machine was used to measure the fracture strength. Results: 1. The fracture strength of the zirconia ceramic crown in the lower 1st molar (2963 N) had the highest and that in the lower central incisor (1035 N) had the lowest. 2. The fracture strength of zirconia ceramic crown was higher than that of the IPS Empress crowns in all tooth position. 3. The fracture mode of the crowns was similar. Most of fracture lines began at the loading area and extended through proximal surface perpendicular to the long axis of the crowns. 4. There were no significant differences on the fracture strength of the zirconia ceramic crowns according to tooth position except in premolar group. Conclusion: Within the limitations of this study, the results suggested that strength of zirconia ceramic crown is satisfactory for clinical use.

• Textile Coloration and Finishing
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• v.10 no.4
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• pp.15-23
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• 1998

본 연구에서는 sizing을 포함하여 염색.가공 공정에서 습.건열 처리 온도를 변화시켜 처리한 폴리에스테르 필라멘트 사와 직물의 물성 변화에 관한 상관성을 연구하였다. 경사는 50d/24f(spark) 그리고 위사는 75d/72f(semi-dull)사를 사용하여 평직물을 셔틀직기에서 제직하였다. 사이징 공정에서의 건조온도를 $90^\circ{C}$, $125^\circ{C}$, $150^\circ{C}$로 변화 시켰으며 수세공정에서 습열 처리온도는 $90^\circ{C}$, $110^\circ{C}$ 그리고 $120^\circ{C}$로 변화시켰다. 그리고 프리세트 공정에서의 건열 처리온도는 $180^\circ{C}$, $200^\circ{C}$ 그리고 $220^\circ{C}$로 변화시켰다. 마지막으로 최종열처리 공정에서는 $170^\circ{C}$, $180^\circ{C}$ 그리고 $200^\circ{C}$로 각각 변화시켜 이들 직물의 인장, 굽힘, 전단 특성과 이들 직물에서 채취한 실의 탄성계수, 절단강도, 변형률 등을 측정하여 각 공정에서의 열처리 온도 변화에 따라 이들 물성치의 상관성을 검토 비교하였다.

• 기계와재료
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• v.2 no.3 s.5
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• pp.120-127
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• 1990

미래지향적 고부가가치의 첨단산업 전반에 걸쳐 기계요소 부품 재료로서 주목받고 있는 화인 세라믹스의 가공에 있어 다이아몬드 연삭 숫돌에 의한 연삭, 절단 가공은 가장 중요한 위치를 차지하고 있는 기계적 제거 가공법이다. 그러나 세라믹스는 고경도, 고강도, 경취성 재료이기 때문에 다이아몬드 지립의 절인 마모가 빨라 능률적인 가공을 장시간 유지하기가 곤란하다. 여기서는 국내 기계 가공 작업 현장에 있어서 부품의 신소재 대체에 따라 필연적으로 사용하게 된 다이아몬드 연삭 숫돌에 대하여 작업자들이 범용 숫돌 사용시의 고정 관념만을 갖고 새로운 공구에 관한 기초 지식이나 Know-how없이 가공작업에 임하는 경우가 많아, 압력 절입 방식에 있어서의 연삭 능률 비교를 중심으로 평면 연삭이나 절단 등의 강제 절입 방식에 있어서의 연삭비, 연삭저항 등의 데이터도 첨부하여 세라믹스 가공을 위한 다이아몬드 연삭공구의 조건에 대해 논하고자 한다.