• 한국재료학회지
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• 제17권11호
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• pp.580-586
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• 2007

To enhance the reliability of a newly designed reciprocating compressor applied in a domestic compressor, accelerated life tests were developed using new definitions of the sample size and the $B_1$ life index. In $1^{st}$ accelerated life testing, the compressor was locked due to the fracture of the suction reed valve. The failure modes and mechanisms of the suction reed valve in the accelerated tests were found to be similar to that of the failed product in the field. The root cause of the failure was the overlap between the suction reed valve and the valve plate in the suction port. The missing parameters in the design phase were modified by expanding the trespan size, introducing tumbling process, changing the material and thickness for the valve, introducing a ball peening and brushing process for the valve plate. In $2^{nd}$ accelerated life testing, the compressor was locked due to the interference between the crank shaft and thrust washer. The corrective plan was to heat treat the crank shaft. The $B_1$ life of the compressor improved from 1.5 to 12.9 years.

• 한국축산식품학회지
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• 제23권4호
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• pp.321-326
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• 2003

The objectives of this study were to develop restructured meat products(RMPs) using a transgluta-minase(TGase) and to improve the textural characteristics of RMPs manufactured with pale, soft, exudative(PSE) pork hams. The pH values of RMPs with PSE and normal pork were 5.94 and 6.07, respectively, and their water activity value was approximately 0.981. The RMPs had 70∼72％ moisture, 4∼5％ fat, 19∼20％ protein, and approximately 3％ ash contents. No differences in pH, water activity, chemical composition, and hunter color values were observed between RMPs manufactured with normal and PSE pork(p＞0.05). However, RMPs containing PSE pork hams had higher drip loss(％)(p＞0.05) than those with normal pork hams after 10 days of refrigerated storage. Although no differences were observed in the texture profile analysis(TPA) hardness and sensory evaluation, RMPs with PSE pork hams tended to have more pores and lower binding capacity those with normal pork. This result indicated that additional substrates or longer tumbling time(＞4 hr) for the manufacture of RMPs containing PSE pork were required for the products to have similar palatability to those with normal pork.

• 펄프종이기술
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• 제37권1호
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• pp.17-24
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• 2005

The increase of using low grade ace, the unsorted mixed grade, as fibrous raw materials for the packaging paper results in the increment of fine screen reject owing to the strong tendency to reduce the slot width. Since the most of screen reject consists of undispersed fiber flake, the suitable treatment of the flake could increase the yield of ace recycling and decrease the amount of solid waste. In this work, the novel method combined the mild mechanical treatment by using Tumbling pulper with the biological treatment was developed and applied to the wet strength flake and the fine screen tail line reject originated from a packaging paper mill. The results showed the new method could provide much better efficiency for the disintegration of undispersed flake and for the recovery of fiber from the rejects. The application of the laboratory scaled-Pack pulper showed the possible separation technique for mill application by fractioning effectively the fiber from the treated solid waste.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권2호
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• pp.74-80
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• 2000

In this paper, we present a control method of mobile power assist systems. Most of mobile power assist systems have a heavy base for preventing easy tumbling, so continual movement of the base during operations causes high energy consumption and gives the high risk of human injury. Furthermore, the slow dynamics of the base limits the frequency bandwidth of the whole system. Thus we propose a cooperation control method of the mobile base and manipulator, which removes the unnecessary movements of the base. In our scheme, the mobile base does not move until the center of gravity(C.G) of the system goes outside a safety region. When C.G. reaches the boundary of the safety region, the base starts moving to recover the manipulator's initial configuration. By varying the parameters of a human impedance controller, the operator is warned by a force feedback that C.G. is on the marginal safety region. Our scheme is implemented by assigning a nonlinear mass-damper-spring impedance to the tip of the manipulator. Our scheme is implemented by a nonlinear mass-spring impedance to the tip of the manipulator. The experimental results show the efficacy of the proposed control method.

• 한국축산식품학회지
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• 제42권5호
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• pp.723-743
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• 2022

Beef muscles from mature cows and bulls, especially those originating from the extremities of the carcass, are considered as underutilized due to unsatisfactory palatability. However, beef from culled animals comprises a substantial proportion of the total slaughter in the US and globally. Modern consumers typically favor cuts suitable for fast, dry-heat cookery, thereby creating challenges for the industry to market inherently tough muscles. In general, cull cow beef would be categorized as having a lower extent of postmortem proteolysis compared to youthful carcasses, coupled with a high amount of background toughness. The extent of cross-linking and resulting insolubility of intramuscular connective tissues typically serves as the limiting factor for tenderness development of mature beef. Thus, numerous post-harvest strategies have been developed to improve the quality and palatability attributes, often aimed at overcoming deficiencies in tenderness through enhancing the degradation of myofibrillar and stromal proteins or physically disrupting the tissue structure. The aim of this review is to highlight existing and recent innovations in the field that have been demonstrated as effective to enhance the tenderness and palatability traits of mature beef during the chilling and postmortem aging processes, as well as the use of physical interventions and enhancement.

• 전자공학회논문지SC
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• 제43권5호
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• pp.19-27
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• 2006

본 논문은 사족 보행 로봇에 대한 내고장성 걸음새의 안정여유도를 개선하는 방법을 논한다. 기존에 제안되었던 재고장성 걸음새는 사족 보행 로봇이 다리 고장이 발생한 후에도 보행을 계속할 수 있게 하였다. 하지만 내고장성 걸음새가 임계 안정여유도를 가지므로 몸체 무게중심의 위치가 순차적으로 바뀔 때에는 걸음새가 불안정해질 수 있다는 약점을 지니고 있다. 본 논문에서는 이러한 약점을 극복하기 위해서 양(陽)으로 안정여유도를 가지는 내고장성 걸음새를 관절고착고장에 대해서 제안한다. 관절고착고장은 로봇 다리의 관절 하나가 한 지점에 고착되어 더 이상 움직일 수 없는 상태를 말한다. 양의 안정여유도는 걸음새 동작 과정에서 한 다리가 이동하기 전에 지지 다리들의 위치를 조정함으로써 얻어질 수 있다. 제안된 걸음새의 우수성을 입증하기 위해서 안정여유도, 보폭 등의 매개 변수들을 중심으로 기존 걸음새와 성능 비교를 수행한다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제15권5호
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• pp.365-369
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• 2009

일반적으로 중첩 윈도우는 스트림 질의에서 흔히 이용된다. 그럼에도 불구하고, 기존의 연구에서는 범플링 윈도우나 튜플-드리븐 윈도우 등의 기본적인 윈도우만을 가정하고 조인 알고리즘을 다루었다. 본 논문에서는 보다 일반화된 윈도우의 형태인 중칩 윈도우상에서 조인을 효율적으로 처리하기 위한 알고리즘을 제안한다. 제안하는 알고리즘은 기본적으로 점증 조인 후 합병하는 방법을 이용한다. 그리고, 대량의 입력으로부터 메모리 오버플로우가 빈번하게 발생하는 상황에서 연속적으로 윈도우 조인 결과를 생성하는 방법에 중점을 두었다. 제안하는 방법은 (1) 점증 조인과 중복을 허용한 완전 조인을 선택적으로 이용하는 방법, (2) 조인 결과의 지연을 최소화하기 위한 필체 대상 선정 방법과 (3) 가용 시간 처리 방법 등을 포함한다. 그리고, 실험을 통해 점증 조인과 완전 조인을 선택적으로 이용하는 것이 하나만 이용하는 기존 방식에 비해 성능이 우수함을 보인다.

• 한국축산식품학회지
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• 제35권1호
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• pp.101-107
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• 2015

The aim of this study was to investigate the effects of various marination processes on the quality characteristics of chicken breast prepared with chicken feet gelatin and wheat fiber. The chicken feet gelatin was swollen with hydrochloric solution (0.1 N HCl, pH $1.31{\pm}0.02$) and dehydrated by freeze-drying. The composition (w/w) of the marinade was water (10%), soy sauce (12%), phosphate (0.3%), wheat fiber (1.5%), and chicken feet gelatin (1.5%). Three samples of chicken breast were manufactured with Tumbler (only tumbler), Tenderizer (tenderizer and tumbler), and Injector (injector and tumbler). The water content of the Injector sample was significantly higher than those of the Tumbler and Tenderizer samples (p<0.05). During heating, the lightness of all chicken breasts increased and the redness decreased. The tumbling and cooking yield of the Injector sample were significantly higher than those of the Tumbler and Tenderizer samples (p<0.05). The shear force of the Tenderizer sample was significantly lower than that of the Tumbler and Injector samples (p<0.05). No significant differences, except for color, were observed in the sensory analysis of the samples. Thus, the proper selection of mechanical processing is important to improve the quality characteristics of marinated chicken breast, considering the types of final products.

• KSBB Journal
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• 제4권3호
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• pp.221-228
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• 1989

각종 섬유질 효소당화반응조내의 현탁액 혼합교반 양상이 효소당화에 미치는 영향을 검토하기 위하여 3종의 대표적인 bioreactor;vertical impeller type bioreactor-(VITB), horizonatl paddle type bioreactor(TDTB)를 제작하여 그 효용성을 비교 검토하였다. 최적 교반강도는 impel-ler나 paddle로 현탁핵을 교반하는 VITB와 HPTB가 각각 100rpm, 그리고 통자체를 회전시켜 교반하는 TDTB가 200rpm이었으며 TDTB에 부착된 baffle의 형태 및 크기는 큰 영향을 주지 않았다. 또한 VITB나 TDTB의 경우 과다한 교반은 효소의 실활을 유발시켜 오히려 섬유소당화를 저해하였다. 3종의 bioreactor의 최적 교반조건에서의 당화효율을 비교한 결과 VITB가 가장 높았으며 특히 고농도 섬유소 당화시 가장 높은 당화효율을 보여, 가장 효율적인 교반양상을 나타내는 것으로 보인다. 이로 미루어 impeller나 paddle의 물리적 충격에 의한 현탁액의 cellulose network를 파괴시키는 효소반응기가 단순히 교반혼합하는 반응기에 비하여 우수한 결과를 줌을 알 수 있었다. 반면 주어진 양의 당을 생산하는데 소요되는 동력소모를 검토한 결과 TDTB가 VITB에 비하여 다소 낮았으나 고농도의 경우는 급속히 증가되었다. 적절한 bioreactor의 선정에는 기질의 가격, 당화수율, 고농도 당화, 그리고 반응기의 scale-up의 용이성등이 종합적으로 검토되어져야 할 것이다.

• Archives of Plastic Surgery
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• 제36권1호
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• pp.118-121
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• 2009

Purpose: Constricted ear, which is named by Tanzer includes lop ear, cup ear, and sort of prominent ear. It has classified three groups by Tanzer, especially grou I and IIA have been corrected by banner flap, Musgrave's technique, tumbling concha - cartilage flap, reversed banner flap and others. However, these techniques were too invasive for correcting mild degree of deformity. Therefore, we corrected the ear with mattress suture which is simple and less invasive. Method: The operations were done against 5 patients from 2005 March to 2008 April. All the cases were unilateral ears with constriction included helix and scaphoid fossa without difference in length between both ears. Though a posterior auricular skin incision, the folded cartilage is exposed and two parallel incisions on superior crus were made. After mattress suturing in cartilage, the superior crus of antihelix was formed and its force enables the folded portion to be in a normal anatomic position. Result: All of 5 patients got satisfactory results. There were no complications like hematoma or skin necrosis, and no recurrence during follow - up period(the average period was 9 months). And we couldn't recognize the difference between height of both auricles. Conclusion: Mattress suture is simple, less invasive, and suitable on correcting mild deformity of constricted ear with better result, so here we suggest the method.