• Speech Sciences
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• v.14 no.4
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• pp.145-156
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• 2007

The performance of speaker identification is severely degraded in noisy environments. Recently probability weighting method based on observation membership was proposed for overcoming the noise problem[1]. In the paper[1] the observation confidence was calculated from SNR with sigmoid function. However, estimating SNR needs additive calculation amount and estimated SNR is corrupted in dynamic noisy environments. In this paper we propose estimation methods of the observation confidence based on score-based reliabilities (SBR) of entropy and dispersion measures. Generally SBRs are obtained from speaker models' probabilities. The proposed methods are evaluated with ETRI speaker recognition DB. We compared the performances of the proposed methods with those in [1][8]. The experimental results show that the proposed methods can be successfully applied for the case where SNR is not available.

• Proceedings of the KIEE Conference
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• summer
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• pp.578-580
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• 2004

Substation facilities have become large and complex in the electric power systems. Development of condition monitoring and diagnosis techniques have been very important to improve the security of substation transformers. This paper presents a method to analyze the cause and the degree of aging of power transformers by Self organizing map(SOM). Dissolved gas data were non-linearly transformed by sigmoid function to make determination of SOM close to that of human. Potential of a failure and the degree of aging of a normal transformer are identified by using the proposed quantitative criterion. Furthermore, transformer aging is monitored by the proposed criterion for a set of transformers. To demonstrate the validity of the proposed method, a case study is performed and its results are presented.

• The Journal of the Korean dental association
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• v.18 no.2 s.131
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• pp.103-108
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• 1980

The occurrence of odontogenic epithelium in the well of a dentigerous cyst is a well known entity. This epithelium usually remains inactive and does not have clinical significance. However, these small inactive islands of epithelium may be stimulated, resulting in an ameloblastoma. Therefore correct diagnosis and proper treatment are very important. A 15 year-old boy came to the outpatient clinic on August 13, 1979. The Chief complaint was pain, difficulty in mouth opening and swelling of the right mandible of 1 month's durations. With the X-ray filming, it was revealed that dentigerous cyst had been originated from the third molar, occurred in posterior region of the right mandible involving the 1st and the and molar and the portion just beneath the sigmoid notch area. Pus discharged from the gingival sulcus distal to the 2nd molar and it was sure that the cyst had been infected. Enucleation performed with careful excision of all cyst wall was successfully carried out, and recovery and heading were rapid and uncomplicated.

• The Korean Journal of Financial Management
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• v.19 no.2
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• pp.211-231
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• 2002

본 연구의 목적은 VECM(Vector Error Correction Model)과 인공지능모형(Artificial Neural Networks)을 이용하여 우리나라 증권시장과 거시경제 변수들과의 장기적 관계에 대한 설명력을 비교해보고자 함에 있다. VECM이 APT(Arbitrage Pricing Theory)에 기초를 둔 선형동학모형이라고 한다면, 인공지능모형은 비모수적 비선형모형이라는 점에서, 두 방법론의 분석결과를 직접 비판하는 것은 의미있는 연구라고 할 수 있다. 인공지능모형을 주로 활용하는 선행연구들에 의하면, 증권시장은 시장의 특이패턴들로 인해 계량경제학적 접근인 선형 모형보다는 인공지능모형을 통해 증권시장의 움직임을 설명하고 예측하는 것이 더 바람직할 수도 있다는 것이다. 따라서, 본 연구에서는 VECM분석에서 자료의 안정성을 검증하고, 공적분 백터를 발견한 이후, 장기적 균형관계의 실증적 분석을 하였다. 그리고, 인공지능모형에서는 delta rule과 Sigmoid 함수를 이용한 GRNN(General Regression Neural Net)과 Back-Propagation등의 방법들을 활용하였다. 이러한 분석결과, Back-Propagation 모형이 다른 모든 모형들보다도 더 우수한 설명력을 보여주고 있었다. 이러한 결과들은 인공지능모형이 동태적인 선형 모형보다도 더 우수한 설명력을 제공할 수 있는 가능성을 보여주고 있었다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.5
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• pp.238-241
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• 2013

Lateral and superior-lateral dislocations of the intact condyle are a rare complication, following traumatic insult to the mandible. We report an unusual case of a 54-year-old male patient who experienced both types of dislocations of the intact condyles with symphysis fracture following a road-traffic accident. Under general anesthesia, conventional manipulation was unsuccessful in relocating the condyles into the glenoid fossa. After applying a percutaneous traction force, using a bone traction hook placed at the sigmoid notch, the displaced intact mandibular condyles were repositioned, and the symphyseal fracture was finally reduced and fixed. The mouth opening was within normal limits, and favorable occlusion was confirmed one month postoperatively. To our knowledge, this is the first case of dislocation of both intact condyles--associated with symphysis fracture--being reduced with bone traction hook.

• Advances in pediatric surgery
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• v.12 no.1
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• pp.99-106
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• 2006

Anorectal malformations comprise a spectrum of disease and the majority of patients have one or more abnormalities that affect other systems. In evaluating a newborn with anorectal malformation, the decision regarding the need for a colostomy and detection and management of any life threatening associated anomalies are thetwo most important considerations. Perineal inspection provides the clue to the surgical approach in about 80-90 % of male and 90 % of female newborn baby. The remaining patients who do not show any clinical evidence need radiologic evaluation to decide whether a colostomy should be performed. In most cases the decision to make a colostomy should not be made until the baby is 20 to 24 hours old and evaluation to rule out the presence of associated anomalies completed. A divided colostomy at the junction of the descending and sigmoid colon is recommended for anorectal malformations.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.3
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• pp.57-64
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• 2015

In this paper, a model reference adaptive control (MRAC) scheme is applied for the precise and robust motion control of a pneumatic system with load variation. The reference model for MRAC is designed systematically using linear quadratic Gaussian control with loop transfer recovery (LQG/LTR). The sigmoid function of inverse velocity is used to compensate for the nonlinear friction force between the sliding parts. The experimental results show that MRAC effectively overcame the limit of the PID controller when there was unknown disturbance, including abrupt load variation and model uncertainty in the pneumatic control system.

• ALGAE
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• v.22 no.3
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• pp.147-152
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• 2007

We described two brownish freshwater Cryptomonas species, C. marssonii Skuja and C. pyrenoidifera Geitler as first records in Korea. The identification was based on light microscopy, scanning electron microscopy, and nuclear SSU rDNA sequences analysis. Cryptomonas marssonii is characterized by its sigmoid shape with a sharply pointed and dorsally curved antapex, dorso-ventrally flattened cell, two lateral plastids without pyrenoid, and its dimension of 18-25 μm in length and 8-13 μm in width. Cryptomonas pyrenoidifera is characterized by ovoid to elliptical shape with a partially twisted or rounded antapex, dorso-ventrally biconvex cell, lateral plastids with two pyrenoids, and the dimensions of 15-22 μm in length and 10-14 μm in width. Nuclear SSU rDNA sequences between C. marssonii WCK01 from Korea and CCAC0086 from Gernmay, and between C. pyrenoidifera WCK02 from Korea and CCMP152 from Australia were identical, respectively.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2002.11a
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• pp.490-501
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• 2002

기업의 생산성향상과 이익률에 영향을 줄 수 있는 지식이 경제 전반에 확산되어 나가는 과정은 한 나라의 경제발전속도에 영향을 미치는 중요한 요인이다. 기업 측면에서는 도입하려는 기술이 도입 후에 그 기업의 이익을 높여 줄 수 있다면 도입하지 않을 이유가 없다. 하지만 미래 수요의 불확실성이나 기술발전 방향의 불확실성 등으로 해서 기업으로서는 도입 후의 이익을 정확히 사전적으로 측정하기는 어렵다. 본 논문에서는 학계에서 일반적으로 사용되고 있는 두 가지 지식확산 모델을 설명하고자 한다. 그 하나는 하나의 새로운 기술이나 상품이 시간이 흐름에 따라 어떻게 전체 사용 가능자(population)에게 확산되는 지를 보여주는 1) Epidemic Diffusion Model (흔히 5자형 - Sigmoid - 모델이라고도 한다. )과 어떤 도입자가 어느 시점에서 대상이 된 새로운 기술을 도입할 것인지 아닌지를 결정하는 모델로서 2) Probit Diffusion Model (프로빗 모델)을 중심으로 한다 그리고 이러한 지식확산과정과 속도에 영향을 줄 수 있는 기업 내부적 요인으로서 도입하고자 하는 기업의 누적된 경험이 중요하다는 것과 기업 외부적 요인으로서 네트웍 효과와 같은 요인들을 설명하였다.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.1
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• pp.1-6
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• 2015

Recently, handy pulse measurement method was introduced by using smart phone camera. However, measured values are not consistent with the variations of external light conditions, because the external light interfere with dynamic range of captured pulse image. Thus, adaptive dynamic range reconstruction algorithm is proposed to conduct pulse measurement robust to light condition. The minimum and maximum values for dynamic ranges of green and blue channels are adjusted to appropriate values for pulse measurement. In addition, sigmoid function based curve is applied to adjusted dynamic range. Experimental results show that the proposed algorithm conducts suitably dynamic range reconstruction of pulse image for the interference of external light sources.