• 한국정밀공학회지
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• 제21권8호
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• pp.83-88
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• 2004

The Classification of defected oil-seals using a vision system with the artificial neural network is presented. The artificial neural network fur classification consists of 27 input nodes, 10 hidden nodes, and one output node. The selection of the number of the input nodes is based on an observation that the difference among the defected, non-defected, and smeared oil-seals is greatly pronounced in the 26 step gray-scale level thresholding. The number of the hidden nodes is chosen as a result of a trade-off between accuracy and computing time. The back-propagation algorithm is used for teaching the network. The proposed network is capable of successfully classifying the defected from the smeared oil-seals which tend to be classified as the defected ones using the binary thresholding. It is envisaged that the proposed method improves the reliability and productivity of the automotive vision inspection system.

• 한국경영과학회지
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• 제36권2호
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• pp.51-65
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• 2011

We compared a CONWIP(constant work-in-process) system with a kanban system in a production line with constant processing times. Based on the observation that a WIP-controlled line production system such as CONWIP and kanban is equivalent to a m-node tandem queue with finite buffer, we applied a max-plus algebra based solution method for the tandem queue to evaluate the performance of two systems. Numerical examples with 6 workstations were used to demonstrate the proposed analysis. The numerical results support the previous studies that CONWIP outperforms kanban in terms of expected waiting time and WIP. Unlike the kanban case, sequencing workstations in a CONWIP does not affect the performance of the system.

• 한국연소학회지
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• 제8권2호
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• pp.41-49
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• 2003

Ultrasonic field of 28kHz with sound pressure level 162dB has been employed to agglomerate the fine soot particle produces in a diffusion flame in a chamber. The agglomeration process has been investigated with digital camcorder and analysed in terms of the decrease of number density with exposure time. From the observation of agglomeration process, the initial agglomeration has been carried out during the short time, and it has been dominated by the orthokinetic collision. Thereafter, a slower agglomeration mechanism, driven by acoustic streaming in the chamber takes over and agglomeraters grew to diameters of several millimeters were levitated at the pressure node of the acoustic wave. And, the circular disk shape of large agglomeraters with the rotational and translational motion is observed.

• 한국정보과학회논문지:데이타베이스
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• 제27권2호
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• pp.216-226
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• 2000

본 논문에서는 무결성 제약을 효율적으로 유지하기 위한 접근 경로인 Hashed B-트리를 제안하고, 기존의 B-트라와 성능을 비교한다. 무결성 제약을 만족시키기 위해 필요한 질의 패턴들이 종점 질의로 구성되어 있다는 점에 착안하여, Hashed B-트리는 키를 해슁을 통해 압축하여 저장한다. 따라서 트리의 높이가 줄어들게 되고 트리의 탐색이 빠르다. 이 기법은 기존의 B-트리와 유사하게 작동하기 때문에 기존 시스템에 많은 수정을 요하지 않고 병행성 제어나 회복 기법을 그대로 사용할 수 있는 장점이 있다.

• 대한미생물학회지
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• 제21권1호
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• pp.145-149
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• 1986

The development of delayed-type hypersensitivity(DTH) reaction to Staphylococcus aureus in mice was studied, Mice received 3 injections of $10^8$ viable S. aureus subcutaneously showed a marked footpad swelling when mice were challenged with $10\;{\mu}g$ staphylococcal protein antigen into footpad(The percent increase of footpad thickness at 24 h after challenge wsa 35% approximately). Histological observation of footpad of immunized mice showed a marked thickness of subcutaneous tissue due to edematous reaction and massive infiltration of lymphocytes and neutrophils which are characteristic cells in DTH reaction. Intensity of DTH reaction of mice immunized with viable bacteria was much higher than that of mice immunized with staphylococcal protein or heat-killed bacteria. The DTH reaction to S. aureus could be transferred to normal recipient mice by both spleen cells and lymph node cells.

• 한국항해항만학회지
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• 제27권4호
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• pp.455-463
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• 2003

저질의 부유 현상이 일련의 쇄파라고 하는 파동 현상에 어떠한 형태로 연동하는가를 면밀히 조사하기 위하여 현지해안의 쇄파대내에 주 관측지점을 설치하고 부유사 농도와 유속, 수위변동 등의 관련 파랑 제원을 계측하였다. 분석을 위해 수위변동, 유속변동치의 부유사 농도에 대한 상관관계를 조사하였으며, 상관이 탁월한 주기대에 대한 ensemble 평균 분석으로 유속 및 수위변동의 위상에 따른 부유사 농도의 변화와의 관계를 명백히 하여 다음의 결론을 얻었다. 1) 부유사의 농도 변동은 유속 및 수위변동의 에너지가 가장 큰 장주기 성분(100s)에 있어서 보다 오히려, 관측지점이 절(node)이 되는 1차mode의 장주기중복파(60s) 및 배(anti-node)가 되는 2차 mode의 중복파(30s)의 주기성분에서 상관이 높았으며, 2)또한, 1차 mode의 장주기중복파의 유속 성분이 해안으로 향하여 가속하는 위상 즉, 수면 경사가 상대적으로 해안선측보다 외해측이 높은 위상에서 부유사 농도가 가장 높아짐을 명백히 하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권1호
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• pp.81-98
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• 2013

Since Probabilistic Latent Semantic Analysis (PLSA) and Latent Dirichlet Allocation (LDA) were introduced, many revised or extended topic models have appeared. Due to the intractable likelihood of these models, training any topic model requires to use some approximation algorithm such as variational approximation, Laplace approximation, or Markov chain Monte Carlo (MCMC). Although these approximation algorithms perform well, training a topic model is still computationally expensive given the large amount of data it requires. In this paper, we propose a new method, called non-simultaneous sampling deactivation, for efficient approximation of parameters in a topic model. While each random variable is normally sampled or obtained by a single predefined burn-in period in the traditional approximation algorithms, our new method is based on the observation that the random variable nodes in one topic model have all different periods of convergence. During the iterative approximation process, the proposed method allows each random variable node to be terminated or deactivated when it is converged. Therefore, compared to the traditional approximation ways in which usually every node is deactivated concurrently, the proposed method achieves the inference efficiency in terms of time and memory. We do not propose a new approximation algorithm, but a new process applicable to the existing approximation algorithms. Through experiments, we show the time and memory efficiency of the method, and discuss about the tradeoff between the efficiency of the approximation process and the parameter consistency.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권6호
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• pp.591-596
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• 2007

Neck node metastasis of oral cancer can be diagnosed by bimanual palpation, CT, MRI and neck sonography and the final diagnosis can be confirmed by pathologic evaluation of the neck nodes after elective neck dissection. When we meet clinically negative neck node(N0 neck) of oral squamous cell carcinoma, the treatment modality of the neck nodes with the primary lesions are so controversial. The usually used methods are various from close observation to elective radiation and elective neck dissection. The methods can be chosen by the primary size of the carcinoma, site of the lesions and the expected percentage of the occult metastasis to the neck. We reviewed the 86 patients from 1996 to 2006 who were diagnosed as oral squamous cell carcinoma, whose necks were diagnosed negative in radiographically and clinically. According to TNM stage, the patients were in the states of N0 and treated by surgery using mass excision and elective neck dissection. We compared the differences between the clinical diagnoses and pathologic reports and would discuss the needs for elective neck dissection.

• 한국콘텐츠학회논문지
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• 제12권5호
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• pp.70-80
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• 2012

3D 입체공간에서 재미와 학습요소가 가미된 해양생물 문화콘텐츠를 개발하고, 도서해양 생물자원의 증강현실 콘텐츠 개발과 체험학습의 활용 방안을 제안한다. 증강현실 저작도구는 위지윅(WYSIWYG) 기반의 저작도구로 Node 구조와 Drag & Drop을 통해 저작도구를 쉽게 사용할 수 있도록 하였다. 해양생물 문화콘텐츠는 marker를 통한 애니메이션 효과, 모델링 데이터의 변화 등의 이벤트 요소를 추가하고, 해양생물 내레이션(narration)으로 실감 체험학습을 지원한다. 해양생물 AR Book은 50여종의 해양생물 증강현실 콘텐츠를 바탕으로 초등학교 수업 교재로 활용이 가능하며, 증강현실을 활용한 3D 입체영상 교육으로 실재적 관찰, 다양한 사고, 최대의 몰입감을 부여하여 학습효과를 높여준다.

• 동의생리병리학회지
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• 제23권5호
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• pp.993-1002
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• 2009

The object of this study was to evaluate the single dose toxicity of Taeumjowui-tang(TUJWT), a polyherbal formula have been traditionally used as prevention or treatment agent for obesity, in male and female mice. Aqueous extracts of TUJWT (Yield = 10.5%) was administered to female and male ICR mice as an oral dose of 2000, 1000 and 500 mg/kg (body wt.) according to the recommendation of KFDA Guidelines. Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after dosing, upon necropsy, organ weight and histopathology of 12 principle organs were examined. As results, we could not find any mortality, clinical signs, and changes in the body and organ weight except for diarrhea restricted in TUJWT 2000 mg/kg treated one male mouse at 1 day after administration, and increases of popliteal lymph node weights in all TUJWT administered groups. In addition, no TUJWT-treatment related abnormal gross findings and changes in histopathology of principle organs were detected except for increases of the frequency of hypertrophy and hyperplasia of lymphoid cells in the popliteal lymph nodes in all TUJWT treatment groups with some sporadic accidental findings. These increases of popliteal lymph node weights with hypertrophy and hyperplasia of lymphoid cells were considered that related to the immune modulate effect of TUJWT not toxicological signs. The results obtained in this study suggest that the TUJWT does not cause any toxicological signs. The 50% lethal dose and approximate lethal dose of TUJWT aqueous extracts in both female and male mice were considered as over 2000 mg/kg.