• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.3
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• pp.295-302
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• 1990

In this paper, a methodology for the automatic design of the optimal systolic arrays is proposed. Algorithm transformation is the main mathematical tool on which this methodology is based. Also, technique for partitioning algorithm into systolic arrays is presented. Algorithm partitioning is essential when the size of the computational problem is larger than the size of the array. This study results in (a) reduction of the design time of systolic arrays for given algorithms, (b) CRT display of the structures of systolic arrays, and (c) automatic designing of the optimal systolic array by the criteria such as the number of processing elements, bands, and communication paths. The procedure for these results was programmed using HP BASIC language on HP-9836 computer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.04b
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• pp.55-56
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• 2009

Small RFID tag antenna were fabricated on Si substrate and their physical and electrical properties were evaluated. With decreasing the size of tag antenna on Si substrate, small SMD-type RFID tags could be fabricated, which is very useful for PCB tracking. Firstly, tag antenna pattern and the electromagnetic properties were simulated with HFSS. The frequency was 13.56MHz, the line-width and line-gap were modeled in the range of $50{\sim}200{\mu}m$. S parameters, SRF, and Q value were calculated from geometry. When the line-width and line-gap were 100um and the loop-turn was 10, the SRF was 80MHZ and the Q value was ca. 9. When the microstrip antenna pattern of aluminum was fabricated by using DC sputtering, Vpp of ca. 1.6V was obtained when the reader-tag distance was 40mm.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.2
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• pp.89-93
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• 2009

Purpose: The purpose of this study is to investigate the clinical and histological features of odontogenic keratocyst Patients and Methods: A retrosective review of 100 patients who were diagnosed as odontogenic keratocyst by hitological findings during the period of January 2000 and December 2005 in the Dept. of Oral and Maxillofacial surgery Pusan National University was consecuted. For each patient, age, sex, location of lesion, initial diagnosis by radiographic features, treatment procedure, hitologic findings and recurrance rate were evaluated. Results: In this study, OKC has male prevalance to female by 1.38:1, and most likely occurs during third decade. The most common site of lesion was mandibular ramus region(34.6%) and the most common symptom was swelling(50%). The most common initial diagnosis by radiographic findings was OKC and cyst enucleation was the most common treatment method. The recurrance rate was 28% and existence of daugther cyst is thought to be most convincing factor for prediction of recurrence. Conclusion: In this study, total recurrence rate was 28% and existence of daugther cyst is thought to be most convincing factor for prediction of recurrence. But, since 97% of patients were treated by enucleation and adjuntive excision, further styudy is need about concordance of recurrence rate with surgical method.

• Journal of Korea Multimedia Society
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• v.9 no.11
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• pp.1435-1444
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• 2006

We present an effective and real-time face detection method based on Principal Component Analysis(PCA) and Support Vector Machines(SVMs). We extract simple Haar-like features from training images that consist of face and non-face images, reinterpret the features with PCA, and select useful ones from the large number of extracted features. With the selected features, we construct a face detector using an SVM appropriate for binary classification. The face detector is not affected by the size of a training data set in a significant way, so that it showed 90.1 % detection rates with a small quantity of training data. it can process 8 frames per second for $320{\times}240$ pixel images. This is an acceptable processing time for a real-time system.

• KSBB Journal
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• v.30 no.5
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• pp.253-256
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• 2015

The antibacterial activity from Tricholoma matsutake extracts were confirmed by minimum inhibitory concentration (MIC) test against various bacteria. Tricholoma matsutake extracts was applied for manufacturing low salted Jeot-gal with sodium DL-malate and sodium nitrite as food preservatives. Due to antibacterial activity from Tricholoma matsutake extracts, MIC of sodium DL-malate and sodium nitrite were significantly reduced to 0.025 g/L and 0.25 g/L, respectively. As a result of this study, a premium low salted Jeot-gal can be developed with low concentration of food preservatives by adding Tricholoma matsutake extracts.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.12
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• pp.633-639
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• 2006

High temperature superconductor (HTS) winding coil is one of the key component in superconducting device fabrication. Double-pancake style coils are widely used for such application. High resistance between pancake coils greatly affects the machine design, operating condition and thus the stability. In order to reduce such resistance, experimentalists are looking for efficient and damage free coil connecting methods. In this respect, here we proposed parallel joining method to connect the coils. This is to do crossly joining with HTS tapes on two parallel HTS tapes. Joint samples between two parallel HTS tapes were prepared by using HTS tapes and current-voltage (I-V) characteristic curves were investigated at liquid nitrogen temperature i.e., 77.3 K. A 20 cm length joint connected between two parallel HTS tapes shows $32.5n{\Omega}$, for currents up to 250 A. A small HTS magnet, having two double pancake sub-coils connected together through new parallel joint method was fabricated and their current-voltage (I-V) characteristic curve was investigated. At 77.3K, critical current(Ic) of 97 A and resistance of $55n{\Omega}$ for currents upto 130 A were measured. At operating current 86 A lower than Ic, Joule heats generated in whole magnet and at joint region between sub-coils were 226 mW and 0.4 mW, respectively. Low Joule heat generation suggests that this joining method may be used to fabricate HTS magnet or windings.

• Journal of KIISE:Software and Applications
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• v.36 no.1
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• pp.82-91
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• 2009

Sign language spotting is the task of detecting and recognizing the signs in a signed utterance. The difficulty of sign language spotting is that the occurrences of signs vary in both motion and shape. Moreover, the signs appear within a continuous gesture stream, interspersed with transitional movements between signs in a vocabulary and non-sign patterns(which include out-of-vocabulary signs, epentheses, and other movements that do not correspond to signs). In this paper, a novel method for designing a threshold model in a conditional random field(CRF) model is proposed. The proposed model performs an adaptive threshold for distinguishing between signs in the vocabulary and non-sign patterns. A hand appearance-based sign verification method, a short-sign detector, and a subsign reasoning method are included to further improve sign language spotting accuracy. Experimental results show that the proposed method can detect signs from continuous data with an 88% spotting rate and can recognize signs from isolated data with a 94% recognition rate, versus 74% and 90% respectively for CRFs without a threshold model, short-sign detector, subsign reasoning, and hand appearance-based sign verification.

• Journal of Korean Society of Rural Planning
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• v.16 no.4
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• pp.61-75
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• 2010

Daily living area can be delimited differently depending on what area is to be focused. Based on regional interaction, the present study empirically analyzed the difference between living areas focusing on rural area and ones relying on urban area. We established two types of living areas in Busan-Ulsan mega city with different focus areas (rural versus urban), using travel OD data (2006). According to the result, the fonn of spatial clusters in urban living area differed from that of spatial clusters in rural area; the boundaries of living area were not fit to those of administrative areas in both types; and living areas in both types tended to extend over more than two administrative areas. The results cast some implications concerning spatial planning and policy for living area delimitation. First, since the spatial structure and interconnection of urban area differs to those of rural area, it is required to delimit living areas discriminatively depending on the objectives of the spatial plan. Additionally, the living area should be established more specifically and systematically by further subdividing the form of spaces depending on the objectives and types of the plan. Second, the administrative areas should be consolidated now that the difference of boundaries of administrative and living areas lead to inconvenience of residents, increased administration costs and scale diseconomy. Lastly, the living areas should be delimited by the metropolitan or mega city planning and thus be reflected to its offsprings.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.39-39
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• 2011

반도체 생산의 주요 공정 중 하나인 세정 공정은 공정 중 발생하는 여러 가지 부산물에 의한오염을 효과적으로 제거하여 수율 향상에 큰 영향을 미친다. 현재 주로 쓰이는 세정 공정은 습식 세정 공정으로 화학 약품을 이용하지만 패턴 손상 및 웨이퍼 대구경화에 따른 문제 등이 대두되어 이를 대체할 세정 공정의 도입이 요구되고 있다. 이에 따라 건식 세정에 대한 관심이 증가하고 있으며 에어로졸 세정이 대표적 공정으로 개발 되었으나 마이크로 단위의 발생 에어로졸 입경으로 인해 패턴 손상 문제를 해결하지 못하였다. 이러한 문제점을 극복하기 위하여 응축에 의해 형성되는 입자 크기를 줄이는 것에 관한 연구가 진행되어 왔고, 대응 방안으로 개발된 것이 가스 클러스터 세정이다. 가스 클러스터란 작동 기체의 분자가 수십, 수백 개 뭉쳐있는 형태 (cluster)를 뜻하며 이 때 형성된 클러스터는 수 nm 크기를 가진다. 그리고 짧은 시간의 응축에 의해 수십 nm 크기까지 성장하게 된다. 즉, 입자로 성장할 수 있는 시간과 환경을 형성하지 않음으로써 작은 크기의 클러스터에 의해 패턴 사이의 오염물질을 물리적으로 제거하고 다시 기체상 물질로 환원되어 부산물을 남기지 않는 공정이다. 이러한 작동 환경을 조성하기 위해서는 진공도와 노즐 출구 속도에 대한 설계 단계부터의 이론적 연구를 통한 입자 크기 예측과 세정 조건에 따라서 발생하는 클러스터의 크기 분포 특성을 측정하는 것이 필수적이다. 따라서 본 연구에서는 실시간 저압 환경에서의 측정이 가능하며, 다양한 크기의 입자를 실시간으로 측정할 수 있는 particle beam mass spectrometer (PBMS)를 이용하여 세정 공정 중 발생하는 클러스터의 크기 분포를 측정하는 연구를 수행하였다. 클러스터의 측정은 노즐에 유입되는 유량과 냉매 온도를 변수로 하여 수행하였다. 각각의 조건에 따라서 최빈값은 오차범위 내에서 일정한 것을 확인하였으며, 50 nm 이하의 값으로 가스 클러스터 공정이 패턴 손상 없이 오염입자를 제거할 수 있음을 실험적으로 확인할 수 있었다. 또한 유량의 증가에 따라 세정에 사용되는 클러스터의 입경이 증가하며, 냉매 온도가 낮아질수록 클러스터 입경이 증가하는 경향을 확인할 수 있었다. 클러스터 크기는 오염 입자와의 충돌에 의해 작용하는 힘으로 오염입자를 제거하는 메커니즘을 사용하는 가스 클러스터 세정 장치에 있어 중요성이 크다 할 수 있으며 추후 지속적 연구에 의한 세정 기술의 최적화가 기대된다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.221-221
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• 2011

수 Tera Watt급의 가속기 및 펄스파워 시스템은 다수의 스위치를 사용하고 있으며, 이와 같은 가속기 및 시스템의 성능은 기체방전 스위치의 성능에 직접적으로 관련되어 있다. 일반적으로 이와 같은 기체방전, 액체방전 고출력 스위치는 다목적으로 많은 연구와 개발에 응용되고 있다. 예를 들어 천둥 펄스전자빔 발생장치는 12개의 Marx gap 및 3개의 100 kV 펄스충전 전기트리거 gap을 가지고 있다. 기체 방전 또는 액체 방전 펄스 충전 갭 스위치의 음극에 펄스 고전압이 인가되면 이로 인하여 음극에서 전자빔이 발생한다. 내부에는 전자빔이 양극과 충돌하는 순간 양극표면에 플라스마가 형성된다. 이와 같은 플라스마 sheath는 축 방향 이극관 안에서 양극 충전 에서 음극으로 팽창하면서 전파하며, 또한 거의 동시에 음극표면에도 플라스마가 형성되어 음극에서 양극으로도 팽창하여 전파하게 된다. 이와 같은 펄스충전 고출력 갭 스위치 안에서 발생되는 방전 플라스마의 특성에 관한 갭 breakdown 과정에 대한 특성연구를 한다. 고출력 스위치의 특성 조건으로는 방전전압, 방전시간, jitter 등이 있다. 본 연구에서는 최대전압 600 KV, 최대전류 88 KA, 펄스 폭 60 ns의 특성을 가지는 고전압 펄스 시스템 '천둥'을 이용하여 방전 챔버에 고전압 펄스를 인가하고 N2와 SF6 혼합기체 종류와 압력에 따른 현상을 전기, 광학적으로 연구하였다. 전극은 구리텅스텐 합금재질의 표준전극을 사용하였고, 전극 간격은 20 mm로 고정하였다. 방전 챔버 압력을 100 torr에서 4 기압까지 변화시켜가며 실험을 진행하였고, N2에 대한 SF6의 혼합비율을 0%~100%까지 변화시키며 실험을 진행하였다. 실험결과 방전전압은 압력이 증가함에 따라 증가하다가 2 기압 이상에서는 완만히 증가하는 경향을 보였고, SF6 혼합비율은 0~10%까지 급격히 증가하고, 그 이상의 혼합비율에서는 완만히 증가하였다. 전자온도는 SF6 혼합비율이 0~10%일 때 급격히 증가하여 이후에는 포화되는 경향을 보였고, 압력에 따라서는 큰 경향성을 보이지 않았다.