• 소성∙가공
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• 제12권5호
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• pp.465-472
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• 2003

Engineering design can be viewed as a decision making process, which involves the nonlinear tradeoffs task among the multiple conflicting attributes and considers the robustness of design. In order to obtain best engineering design, methodology for accurate assessment of his/her preference about the multiple attributes is required. Conventionally, intuitive procedures based on lottery questions are used to elicit the designer's preference structure: however, they can lead to inconsistent and inexact preference results due to the rank reversal problems derived from the designer's big cognitive burden. In this paper, alternatively, a design methodology based on multiattribute utility function through the pairwise comparison among alternatives is presented. The proposed procedure is applied to an actual injection mold design with the aid of the CAE simulation and the result is discussed.

• 한국임상수의학회지
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• 제19권2호
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• pp.132-138
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• 2002

Non-human primates are widely used for experimental animal and raised as companion animal in Korea. To establish the electrocadiogram (ECG) of non-human primates that are domestically raised, the author measured bipolar limb leads and augmented unipolar limb leads, after tiletamine/zolazepam (TZ) injection as sedative agents. The amplitudes of P,Q, R,S and T wave and duration time of P wave, QRS complex, PR and QT interval in each lead of ECG were evaluated in 7 non-human primates at 15 minutes after TZ injection, respectively. The amplitude of P wave in I, II,III, aVR, aVL and aVF leads revealed 0.06$\pm$ 0.05,0.14$\pm$ 0.05, 0.1 $\pm$ 0.05,-0.11 $\pm$ 0.06,-0.04$\pm$ 0.04 and 0.12$\pm$ 0.05 mV respectively. The amplitude of Q wave revealed -0.16$\pm$ 0.15, -0.23$\pm$ 0.18, -0.17$\pm$ 0.13, 0.16$\pm$0.13, 0.04$\pm$ 0.09 and -0.2$\pm$0.13 mV, respectively. The amplitude of R wave revealed 0.56$\pm$0.56, 1.24$\pm$ 0.67, 0.92$\pm$0.33, -0.37$\pm$ 1.14, -0.22$\pm$ 0.47 and 1.12 $\pm$ 0.47 mV, respectively. The amplitude of S wave revealed -0.02$\pm$ 0.08, -0.04$\pm$0.06, -0.06$\pm$0.04, 0.02$\pm$0.04, 0.04$\pm$0.09 and -0.04 $\pm$ 0.06 mV, respectively. The amplitude of T wave revealed -0.01 $\pm$ 0.15,-0.02$\pm$ 0.13, 0.01 $\pm$ 0.08, 0.02$\pm$ 0.12, 0.01 $\pm$ 0.11 and -0.03$\pm$ 0.09 mV, respectively. The duration time of P wave revealed 0.05 $\pm$ 0.01, 0.04$\pm$ 0.01, 0.05$\pm$ 0.02, 0.05 $\pm$ 0.02, 0.04$\pm$ 0.01 and 0.04$\pm$ 0.01 sec, respectively. The duration time of QRS complex revealed 0.05 $\pm$ 0.02,0.05$\pm$ 0.01, 0.05 $\pm$ 0.01, 0.04$\pm$ 0.01, 0.05$\pm$ 0.01 and 0.05 $\pm$ 0.01 sec, respectively. The duration time of PR interval revealed 0.08$\pm$ 0.01, 0.07$\pm$0.01,0.08$\pm$ 0.03, 0.08$\pm$0.01, 0.08$\pm$ 0.01 and 0.08$\pm$0.01 sec, respectively. The duration time of QT interval revealed 0.23$\pm$ 0.06, 0.22$\pm$ 0.05, 0.23 $\pm$ 0.06, 0.23$\pm$ 0.06, 0.24$\pm$ 0.05 and 0.22$\pm$ 0.02 sec, respectively. No significant changes were observed in e amplitude of P and T waves. The amplitude of QRS complex in ketamine group was higher than that of TZ group. However, no significant changes were observed in both intra-group and inter-group. There were no significant changes in the duration time of P wave, QRS complex and PR interval obtained from both groups. Also, the duration time of QT interval in TZ group was significantly longer at 30 min.(P< 0.05) an that of 10 minutes after injection. However, significant difference was not found between two groups. The mean cardiac electric axis in ketamine group tended to decrease until 30 min. after injection and then gradually increase. However, mean cardiac electric axis of TZ group was increased until 30 min. after injection and then decreased. But significant differences were not observed between groups. These results suggest that the ECG pattern after TZ injection to non-human primates reared in korea was established. It was also considered that the injection of ketamine and TZ didn't significantly affect on ECG pattern of the non-human primates.

• Korea-Australia Rheology Journal
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• 제14권3호
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• pp.107-114
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• 2002

Residual stress distribution in injection molded short fiber composites is determined by using the layer-removal method. Polystyrene is mixed with carbon fibers of 3% volume fraction (4.5% weight fraction) in an extruder and the tensile specimen is injection-molded. The layer-removal process, in which removing successive thin uniform layers of the material from the surface of the specimen by a milling machine, is employed and the resulting curvature is acquired by means of an image processing. The isotropic elastic analysis proposed by Treuting and Read which assumes a constant Yaung’s modulus in the thickness direction is one of the most frequently used methods to determine residual stresses. However, injection molded short fiber composites experience complex fiber orientation during molding and variation of Yaung’s modulus distribution occurs in the specimen. In this study, variation of Yaung’s modulus with respect to the thickness direction is considered for calculation of the residual stresses as proposed by White and the result is compared with that by assuming constant modulus. Residual stress distribution obtained from this study shows a typical stress profile of injection-molded products as reported in many literatures. Young’s modulus distribution is predicted by using numerical methods instead of experimental results. For the numerical analysis of injection molding process, a hybrid FEM/FDM method is used in order to predict velocity, temperature field, fiber orientation, and resulting mechanical properties of the specimen at the end of molding.

• 한국산학기술학회논문지
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• 제12권7호
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• pp.2963-2968
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• 2011

플라스틱 사출 제품은 다양한 가전제품과 하이테크 제품에 널리 사용되고 있다. 그러나 플라스틱 사출 제품 제조업자들은 고객을 만족시키면서 경쟁력을 얻기 위하여 다른 경쟁자들보다 먼저 새로운 제품을 시장에 출시하고 신제품의 개발기간을 줄이기 위한 노력을 할 여유가 부족하다. 따라서 무한 경쟁의 시장에서 살아남기 위해서는 제조업자들은 시장 마켓 점유를 빠르게 올리는 것과 동시에 제품의 가격 경쟁력을 가져야 한다. 본 연구에서는 하이브리드 인공신경망과 유전자 알고리즘을 이용한 특징기반 플라스틱 사출제품의 비용 평가 모델을 제안한다. 제안하는 방법은 기존의 플라스틱 사출제품의 비용평가절차와 계산을 위해 필요로 하는 변수들을 극적으로 간단하게 하고 줄일 수 있다. 사례연구는 제안하는 모델이 플라스틱 사출 제품의 개발단계에서의 비용평가문제를 해결하는데 효율성과 효과성이 있음을 입증한다.

• Journal of Microbiology and Biotechnology
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• 제27권10호
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• pp.1892-1895
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• 2017

IK can downregulate interferon-gamma-induced major histocompatibility complex (MHC) class II expression through the MHC class II transactivator, which suggests that IK can inhibit the interactions between immune cells. We delivered adeno-associated virus serotype 2 (AAV2) encoding the genes for truncated IK (tIK) or green fluorescent protein (GFP) to DBA1/J mice via intravenous injection. Seven weeks after injection, collagen-induced arthritis was induced in the AAV2-treated mice. AAV2-tIK injection reduced the severity of arthritis and the percentage of pathogenic Th17 cells compared with AAV2-GFP injection. These results suggest a novel gene therapy strategy for treatment of inflammatory arthritis.

• ETRI Journal
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• 제39권4호
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• pp.605-613
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• 2017

Simulated fault injection (SFI) is widely used to assess the effectiveness of fault tolerance mechanisms in safety-critical embedded systems (SCESs) because of its advantages such as controllability and observability. However, the long test time of SFI due to the large number of test cases and the complex simulation models of modern SCESs has been identified as a limiting factor. We present a method that can accelerate an SFI tool using a checkpoint forwarding (CF) technique. To evaluate the performance of CF-based SFI (CF-SFI), we have developed a CF mechanism using Verilog fault-injection tools and two systems under test (SUT): a single-core-based co-simulation model and a triple modular redundant co-simulation model. Both systems use the Verilog simulation model of the OpenRISC 1200 processor and can execute the embedded benchmarks from MiBench. We investigate the effectiveness of the CF mechanism and evaluate the two SUTs by measuring the test time as well as the failure rates. Compared to the SFI with no CF mechanism, the proposed CF-SFI approach reduces the test time of the two SUTs by 29%-45%.

• 한국생산제조학회지
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• 제19권1호
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• pp.57-64
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• 2010

Metal Injection Molding (MIM) is attractive because it produces consistent, complex-geometry components for high-volume, high-strength, and high-performance applications. Also MIM using in optical communication field, display field, and semi-conductor field is a cost-effective alternative to metal machining or investment casting parts. It offers tremendous single-step parts consolidation potential and design flexibility. The objective of this paper is to study the suitability of design, flow analysis, debinding and sinterin processes, and capability analysis. The suitable injection conditions were 0.5~1.5 second filling time, 11.0~12.5 MPa injection pressure derived from flow analysis. The gravity of the product is measured after debinding an sintering. The maximum and minimum gravity levels are 7.5939 and 7.5097. the average and standard deviation are 7.5579 and 0.0122; when converted into density, the figure stands at 98.154%. According to an analysis of overall capacity, PPM total, which refers to defect per million opportunities(DPMO), stands at 166,066.3 Z.Bench-the sum of defect rates exceeding the actual lowest and highest limits-is 0.97, which translates into the good quality rate of around 88.4% and the sigma level of 2.47.

• 대한후두음성언어의학회지
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• 제30권2호
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• pp.77-81
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• 2019

Dysphagia may result from dysfunction of any of the components involved in the complex neuromuscular interaction of swallowing. Hyperfunction of any of the muscles involved in swallowing is a frequent cause of dysphagia. The cricopharyngeus muscle (CPM) is a key component of the upper esophageal sphincter. Cricopharyngeus muscle dysfunction (CPD) refers to the muscle's failure to appropriately and completely relax or expand during deglutition. A variety of disease processes may cause CPD and accurate diagnosis is paramount for appropriate treatment. In appropriately selected patients, intervention at the CPM may yield significant improvement in dysphagia. Interventions include nonsurgical, pharyngoesophageal segment dilatation, botulinum toxin (BoNT) injection, and criccopharyngeal myotomy. Injections of BoNT in patients with CPD have been reported to result in marked relief of dysphagia. Different techniques for instilling BoNT into the CPM have been described. Awake, in-office CPM BoNT injection with electromyography and/or fluoroscopic or ultrasound guidance is performed transcervically or via flexible endoscopy. Operative CPM BoNT injection involves rigid laryngoscopy and esophagoscopy with direct visualization of the CPM. BoNT should be prepared in low-volume, high-concentration dilutions to minimize the potential for undesired diffusion of the toxin. The effects of BoNT occur within weeks of injection and typically last up to 5 or 6 months.

• 한국기계가공학회지
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• 제9권2호
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• pp.60-65
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• 2010

Injection molding process is one of the popular manufacturing methods to produce plastic parts with high efficiency and low cost. The tub-drum for drum type washer is made by an insert injection molding process with aluminum alloy insert of windmill type and has a big and complex structure consisted of many ribs to sustain the strength. In this paper, the volumetric shrinkages of rib part and bottom part surrounded by a windmill type insert are analyzed according to the vertical and circumferential direction of tub-drum. Volumetric shrinkage and its difference according to the height or radius of tub drum inform the designer to reduce the warpage of tub drum, and the optimal design of tub drum can be done from the those results. The change of volumetric shrinkage according to packing pressure is also analyzed. It is very important to analyze the volumetric shrinkage of tub drum because it generates the wearing phenomena at the rotating part connected to an aluminum alloy insert due to the warpage of tub drum.

• 한국결정성장학회지
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• 제26권6호
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• pp.258-262
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• 2016

Foam reaction injection molding (FRIM) is a widely used process for manufacturing polyurethane foam with complex shapes. The modified theoretical model for polyurethane foam forming reaction during FRIM process was established in our previous work. In this study, using the modified model, parametric study for FRIM process was performed in order to optimize experimental conditions of FRIM process such as initial temperature of mold, thickness of mold, and injection amount of polymerizing mixture. In addition, we applied the modified model to real application of refrigerator cabinet to determine optimal manufacturing conditions for polyurethane FRIM process.