다층 신경회로망의 시스톨릭 어레이 구현에 관한 연구

尹賢植 충주대 산업과학기술연구소 1999 産業科學論文集 Vol.7 No.1

I proposed a new design method for a high speed neural network. A processing element is designed based on the systolic array architecture for VLSI implementations. Mathematical operations on vectors and matrices are the key common features of all neural network models. The parallelism and the recursive feature of matrix-vector operations in the neural network processing also lead to the design of systolic array architecture. In this thesis, it is shown that 2-D array processing for computing matrix-vector multiplications can be mapped into an 1-D array architecture. This mapping process is applied to the implementation of Back Propagation (BP) network.

머리염색이 인체에 미치는 영향

윤형식,황성호,이현륭,김수호,박연석,권낙현,정호진,김동훈,노현주,홍성호,박병찬,이관,정해관 東國大學校醫學硏究所 2002 東國醫學 Vol.9 No.1

일상생활에서 모발염색은 흔히 접할 수 있는 미용의 한 종류로 특히 젊은층을 중심으로 폭발적으로 유행하고 있다. 염색을 위항 사용하는 약제는 표백제와 발색제 등 각종 화학약품이 사용되고 있으나 이로 인한 건강장해에 대한 연구는 그리 많지 않다. 저자들은 염색이 인체의 모발건강에 미치는 영향을 파악하기 위하여 염색과 관련된 주관적 증상과 모발의 변화에 대한 실험적 연구를 시행하였다. 동국대학교 경주 캠퍼스 재학생 80명을 대상으로 설문조사를 시행하여 염색 유 ·무 및 염색 후에 경험한 증상에 대해 설문 조사하였고, 의과대학 재학생 46명을 대상으로 피부 반응 테스트를 실시하였다. 또한 염색 전후의 모발 탄성도를 측정하였고 모발의 상태를 파악하기 위해 전자 현미경검사를 실시하였다. 설문조사 결과 염색 전에 비하여 염색 후 안구혼탁, 안구건조, 시력저하, 발진 및 접촉성 피부염, 모발손상, 모근손상 등의 증상을 더 많이 경험한다고 호소하였다(p<0.05). 모발손상과 모근손상은 헤어드라이어 사용 빈도에 따라 증가하는 것으로 조사되었다(p<0.05). 피부반응검사에서 가려움증이 가장 많은 증상이었으며 이는 여성보다는 남성에서 높은 것으로 조사되었다. 염색 전후의 모발장력은 염색 전 134.5±10.37g, 염색 128.0±30.69g, 염색 이틀 후 112.5±19.69g으로 나타났다. 염색 전후의 모발의 전자현미경 케라틴 층이 현저히 감소하고 모발이 가늘어지는 차이를 보였다. 염색은 모발손상, 모발 케라틴 손상 및 모근 손상, 발진 및 접촉성 피부반응, 안구혼탁, 안구건조, 시력 저하를 유발한다. 따라서 염색약으로 인한 손상에 대한 주의와 예방이 필요하다고 생각한다. 예방대책으로 염색 전 피부테스트를 통한 적합성 여부를 판단하는 것이 필요하며 가급적 염색을 피하는 것이 좋을 것이다. 염색약에 발암물질이 포함되어있다는 보고도 있어 염색 제조사의 철저한 실험과 염색 물질의 선별이 염색으로 인한 부작용을 최소화하는데 중요한 역할을 할 것이다. Hair coloring has became one of the most popular cosmetic activities to younger generations during last decade. However, there are few studies on the health effect of widespread use of chemical dyes. This study was conducted to study the effects of hair coloring dye on hair and other systems. We conducted a questionnaire survey of 80 persons in Kyongju campus, Dongguk University. We have done open patch skin test on 46 medical students. We also conducted scanning electron microscopy to examine the hair strength and structure before and after hair coloring process. Injury of hair and hair bulb, contact dermatitis, turbid eyes, xerophthalmia, and poor visual acuity were the main symptoms complained after hair coloring (p<0.05). Injury of hair and hair bulb were increased by frequency of hair-dryer use(p<0.05). In open patch test, pruritus was complanined by more than half of the subjects. Mean strength of hairs before and after hair coloring was as follows; 134.5 (SD 10.37)g before hair coloring, 128.0 (SD 30.69)g immediately after hair coloring, and 112.5 (SD 19.69)g after two days. The scanning electron microscopic findings of hair surface before and after hair coloring showed decreased keratin layer and thinning of the hair. Hair coloring induces injury to hair, its keratin layer, and hair bulb as well as contact dermatitis, turbid eyes, xerophthalmia, and poor visual acuity. Therefore, we think that precaution is needed in use of hair coloring dye. To prevent complications induced by hair coloring dye, it is necessary, especially to those with allergy or skin disorders, to perform skin test before action and avoid hair coloring whenever possible. Longterm health effects of hairdye should be studied and manufacturing companies should try to minimize complications induced by hair coloring dye.

저전력 모드 Bluetooth 시스템을 이용한 파일 전송에 관한 성능 분선

윤현성,이민혁,변건식 동아대학교 정보기술연구소 2002 情報技術硏究所論文誌 Vol.9 No.2

Bluetooth is the name given to a new technology standard using short-range radio links, intended to replace the cable(s) connecting portable and/or fixed electronic devices. The standard defines a uniform structure for a wide range of devices to communicate with each other, with minimal user effort. Its key features are robustness, low complexity, low power and low cost. The standard is aimed at achieving global acceptance such that any Bluetooth device, anywhere in the world, can connect to other Bluetooth devices in its proximity , regardless of brand. Bluetooth enabled electronic devices connect and communicate wirelessly via short-range, ad hoc networks called piconets. Each unit can simultaneously communicate with up to seven other units per piconet. Moreover, each unit can simultaneously belong to several piconets. These piconets are established dynamically and automatically as Bluetooth devices enter and leave the radio proximity.

재원기간중 사망한 급성 심근경색증 환자의 임상적 특징

현대우,김기식,신이철,박소영,배장호,한창엽,김윤년,김권배 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.9

골아세포 MC₃T₃-E₁의 증식과 기능에 Insulin Like Growth Factor Ⅰ, Ⅱ 및 부갑상선 호르몬이 미치는 영향

윤현구,정호연,양인명,김성운,김진우,김광원,김영설,최영길,서광식 대한내과학회 1992 대한내과학회지 Vol.42 No.1

MC₃T₃-E₁골아세포군을 이용하여 IGF-Ⅰ과 Ⅱ를 투여하고 DNA합성과 골아세포기능을 측정하기 위해 PTH에 대한 C-AMP반응정도, alkaline phosphatase 활성도를 측정하여 다음과 같은 결과를 얻었다. 1) IGF-Ⅰ과 Ⅱ는 모두 DNA합성이 어느 농도까지는 증식효과를 나타내지만 그 이후에는 억제되는 양상을 보였다. 2) PTH에 대한 골아세포의 C-AMP반응으로 증가되었지만 IGF-Ⅰ과 Ⅱ의 투여시 농도변화에 따른 의미있는 변화는 없었다. 3) 본 실험의 조건에서 alkaline phosphatase 활성도는 증가되지 않았다. 이상의 결과로 MC₃T₃-E₁ 골아세포에 IGF-Ⅰ과 Ⅱ는 세포의 증식을 자극하여 PTH는 C-AMP생성을 촉진하는 효과가 있었다. The effect of insulin-like growth factor (IGF) Ⅰ and Ⅱ on cloned MC₃T₃-E₁ cells that had osteoblastic activity was examined by [³H] thymidine incorporation into DNA, cyclic AMP responsiveness to parathyroid hormone (PTH), and alkaline phosphatase activity. IGF Ⅰ and Ⅱ stimulated the growth and proliferation of osteoblastic cells at 20ng/㎖ and 50ng/㎖, respectively. We next examined the effect of IGF-Ⅰ and Ⅱ on the expression of osteoblastic activity. Adenylate cyclase response of PTH to IGF-Ⅰ and Ⅱ-treated cells showed maximal stimulation at 10 and 50㎚PTH, respectively, but IGF Ⅰ and Ⅱ induced limited activity of osteoblastic function. In conclusion, IGF-Ⅰ and Ⅱ were potent stimulators to the growth of osteoblastic cells but did not have an immediate effect on expression of osteoblastic function in this experiment.

상심실성 빈맥환자에서 관상정맥동의 형태비교

현대우,김윤년,박소영,한성욱,허승호,김기식,김권배 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.4

U-Healthcare 시스템을 위한 6LoWPAN에 관한 연구

윤현식 忠州大學校 2010 한국교통대학교 논문집 Vol.45 No.-

IEEE 802.15.4 is the standard wireless link technology for low power, low cost, low data-rate, but long lifetime applications including wireless sensor network (WSN). Currently, whether or not IP architecture should be used in WSN over its 802.15.4 link is under dispute. One view is that IP architecture is not suitable for WSN; instead ad hoc network architecture is more preferred to be designed specifically for it. In contrast, IP architecture is seen more as an opportunity for WSNs, even some extra overhead is tolerable taking into consideration the benefits it will bring; and it is also argued that such overheads may actually be minimized through optimization. Such kind of arguments may last for a long time without some convincing experimental measurements of real case performances of IP over 802.15.4 implementation, and thus prevent the advance of related research. In RFC4944, IETF proposed the 6LoWPAN specification to enable IPv6 communication over low power, wireless personal area networks. Since then, we see a great demand and value of making an evaluation of this specification. In this paper, we carry out a performance evaluation of 6LoWPAN on the memory footprint, network capability, transmission delay, and routing cost using a Berkeley 6LoWPAN implementation, b6LoWPAN, on Tmote Sky running TinyOS 2.1. We try to alleviate the dispute and make the direction clearer to the community so as to promote further valuable research in this topic.

잉여수계 신경망의 고속 연산 알고리즘에 관한 연구

尹賢植 忠州大學校 1998 한국교통대학교 논문집 Vol.33 No.2

We propose a design algorithm for fast computation and shrinking the hardware size of the sigmoid function generator in digital neural networks(DNN). Because the DNN is composed of massive distributed parallelism and a lot of data buses, it needs a high speed processors and small hardware structure in the same time. The proposed algorithm is superior to the digital neural network system with floating point processing structure in the same conditions. From the results of computer simulation, Look-up table should be taken larger size in order to converging target error under 10??, because accuracy of neural network applications decide modulo and in that case, sigmoid function values in the look-up table are changed with I/O values and error degrees. The proposed algorithm is avaliable to the pattern recognition field for the merit of residue number system.

애드혹 시스템을 위한 비디오 스트리밍에 관한 연구

윤현식 忠州大學校 2007 한국교통대학교 논문집 Vol.42 No.-

Now-a-days, wireless communication network technology has created variety types of advanced wireless systems. This paper accomplishes the research of Ad-Hoc wireless networks technology to apply wireless multimedia streaming services. specially, to introduce embedded multimedia streaming system. The result of study in this paper will provide the more efficient streaming video and audio services in the field of Ad-Hoc wireless networks.

디지탈 신경망의 시그모이드 함수 연산회로에 관한 연구

尹賢植 충주대학교 1997 한국교통대학교 논문집 Vol.32 No.2

In this paper, the arithemtic circuit design method of sigmoid function generator in order to reducing the chip size and high speed of processing, using MRC (Mixed-Radix Conversion) As a result of computer simulation,proposed algorithm has been identified a simple circuit and high speed processing in comparison with using general floating -point processor