• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.5A
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• pp.889-901
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• 2001

본 논문에서 Multiprotocol Label Switching 시스템을 위한 Label Distribution Protocol의 개발과 분석에 관해서 기술한다. 먼저 Gigabit Switched Router를 만들기 위해서, 상용화시 Carrier Class 제품에 적용하기 위한 LDP의 구현시 고려해야 될 사항에 대해 살피고, 상세 설계를 제안한다. IETF 표준에 의거한 LDP의 구현을 위한 상세 설계는 프로토콜 상태기계의 유도 트리와 프로세스 대수를 사용한 형식적 명세를 사용하여 제시한다. 본 논문에서는 제시된 유도트리와 프로세스 대수를 사용한 프로토콜 동작의 분석을 통해, 구현된 LDP의 상호 연동성과 완전성, 생존성, 도달성, 안전성을 검증한다. 또한 이를 사용하여 구현된 LDP가 기존 상용 제품들과의 연동성과 그 동작의 신뢰성을 확보할 것을 기대한다. 결과적으로 구현된 LDP의 프로토콜 동작들의 검증을 제공한다.

• ETRI Journal
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• v.32 no.5
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• pp.784-794
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• 2010

Automatic facial expression recognition has many potential applications in different areas of human computer interaction. However, they are not yet fully realized due to the lack of an effective facial feature descriptor. In this paper, we present a new appearance-based feature descriptor, the local directional pattern (LDP), to represent facial geometry and analyze its performance in expression recognition. An LDP feature is obtained by computing the edge response values in 8 directions at each pixel and encoding them into an 8 bit binary number using the relative strength of these edge responses. The LDP descriptor, a distribution of LDP codes within an image or image patch, is used to describe each expression image. The effectiveness of dimensionality reduction techniques, such as principal component analysis and AdaBoost, is also analyzed in terms of computational cost saving and classification accuracy. Two well-known machine learning methods, template matching and support vector machine, are used for classification using the Cohn-Kanade and Japanese female facial expression databases. Better classification accuracy shows the superiority of LDP descriptor against other appearance-based feature descriptors.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.521-524
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• 2003

인터넷 데이터 트래픽의 증가로 인한 광 전달망에서의 효율적인 트래픽 이용에 대한 관심이 집중됨에 따라 제어평면상의 라우팅 및 시그널링 제공 방안에 관한 연구의 필요성이 대두 되고 있다. 광 네트워크의 시그널링 인터페이스 구조는 UNI와 NNI로 구분되며, 본 논문에서는 서브 네트워크간 인터페이스인 NNI 상에서의 신호/연결제어 경로를 만들기 위해 수행되는 CR-LDP 시그널링의 여러 기능과 메커니즘을 통해 NNI 에서의 sub-area 의 개념을 적용시킨 효율적인 광 전달망 내에서의 신호 프로토콜 제공 방안에 대해 연구하고, GMPLS의 시그널링 프로토콜중 CR-LDP 를 이용하여 트래픽 엔지니어링 지원 방안을 살펴봄으로써, NNI 내에서의 효과적인 시그널링 제공을 위한 연구 방안을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.957-960
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• 2017

디지털 비디오의 발전이 가속됨에 따라, 비디오 샷 경계 검출은 비디오 분석 및 카타로깅 등 여러 분야에 있어 필수적인 요소가 되었다. 기존 샷 경계 검출 방법들은 잠음이나 카메라 혹은 물체의 이동, 그리고 색상의 급격한 변화 등에 민감한 성능을 보인다. 본 논문에서는 개선된 지역 방향 패턴 기반(eLDP) 검출 방법을 제안한다. 제안하는 방법은 RGB 색상의 일부와 eLDP의 특징을 결합해 더욱 강인한 샷 경계 검출 성능을 보였다. 또한, 셋톱박스 품질검사 시 필요한 채널 간 동기화의 신뢰성을 높였고, 실시간으로 검사하면서도 안정적인 샷 경계 검출이 가능함을 입증하였다.

• Archives of Pharmacal Research
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• v.29 no.6
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• pp.514-519
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• 2006

A simple HPLC method using UV detection was developed and validated for the determination of levodropropizine (LDP) In dog plasma. The sample was prepared for injection using a liquid-liquid extraction method with 1-phenypiperazine as the internal standard. The mobile phase was methanol - diethylamine solution (0.05 M) (20:80, v/v, pH adjusted to 3.0 with $H_3PO_4$) with a detection wavelength of 240 nm. The limit of quantitation (LOQ) of LDP in a biological matrix was determined to be 25.25 ng/mL. The calibration curve was linear across the concentration range of 25.25 to 2020 ng/mL. The intra-day and inter-day precision values (CV%) were within 7% and accuracy (R.E. %) was within 6% of the nominal values for medium (252.5 ng/mL) and high (2020 ng/mL) LDP concentrations. For the LDP concentration at the LOQ, the intra-day and inter-day precision and accuracy were within 20% and 10%, respectively. The average absolute recovery for LDP was 70.28%. This method was successfully used to analyze plasma samples in a steady-state bioavailability study of a newly developed sustained-release LDP tablets (SR) using immediate-release tablets (IR) as the reference. The relative bioavailability of the SR was determined to be $106.3\;{\pm}\;12.8%$ (n=6). The $C_{max}$ of the SR was significantly lower (p<0.05), and the $t_{max}$ was significantly longer than that of the IR (p<0.05). The results of ANOVA and two one-sided tests indicated that the SR exhibited acceptable sustained release properties and was bioequivalent to the IR.

• Journal of the Korea Society of Computer and Information
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• v.26 no.12
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• pp.19-27
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• 2021

In this paper, we present a method for effectively predicting traffic volume based on vehicle location data that are collected by using LDP (Local Differential Privacy). The proposed solution in this paper consists of two phases: the process of collecting vehicle location data in a privacy-presering manner and the process of predicting traffic volume using the collected location data. In the first phase, the vehicle's location data is collected by using LDP to prevent privacy issues that may arise during the data collection process. LDP adds random noise to the original data when collecting data to prevent the data owner's sensitive information from being exposed to the outside. This allows the collection of vehicle location data, while preserving the driver's privacy. In the second phase, the traffic volume is predicted by applying deep learning techniques to the data collected in the first stage. Experimental results with real data sets demonstrate that the method proposed in this paper can effectively predict the traffic volume using the location data that are collected in a privacy-preserving manner.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.26 no.1
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• pp.118-123
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• 2022

A recent successful prospective randomized control study comparing open distal pancreatectomy with laparoscopic distal pancreatectomy (LDP) has shown that LDP is a safe and effective surgical modality in treating left-sided pancreatic pathological conditions requiring surgical extirpation. With the accumulating surgical experiences and improved surgical techniques, we recently reported several cases of successful LDP in advanced pancreatic cancer following neoadjuvant chemotherapy. Herein, we report a case of LDP with celiac axis resection (LDP-CAR) in locally advanced pancreatic cancer (LAPC) following neoadjuvant chemotherapy. A 58-yearold female with LAPC was referred to our institution. Computed tomography (CT) findings revealed a 24-mm mass in the pancreatic body that showed celiac artery (CA), common hepatic artery abutment. There was no abutment with superior mesenteric artery, superior mesenteric vein, and portal vein. From these findings, Neoadjuvant chemotherapy (FORFIRINOX) was performed biweekly. After 8 cycles of chemotherapy, the tumor size was slightly decreased (24 mm to 16 mm), but still abutting to CA. After 14 cycles of chemotherapy, CT revealed the same tumor size (16 mm) still abutting to CA. LDP-CAR was performed. Intraoperative ultrasonography gastric perfusion and hepatic perfusion were confirmed using indocyanine green. The patient recovered without complications and was discharged from the hospital nine days after the surgery.

• Journal of Korea Multimedia Society
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• v.13 no.9
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• pp.1337-1347
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• 2010

Fingerprint recognition is a biometric technology to identify individual by using fingerprint features such ridges and valleys. Most fingerprint systems perform the recognition based on minutiae points after acquiring a fingerprint image from contact type sensor. They have an advantage of acquiring a clear image of uniform size by touching finger on the sensor. However, they have the problems of the image quality can be reduced in case of severely dry or wet finger due to the variations of touching pressure and latent fingerprint on the sensor. To solve these problems, the contactless capturing devices for a fingerprint image was introduced in previous works. However, the accuracy of detecting minutiae points and recognition performance are reduced due to the degradation of image quality by the illumination variation. So, this paper proposes a new LDP-based fingerprint recognition method. It can effectively extract fingerprint patterns of iterative ridges and valleys. After producing histograms of the binary codes which are extracted by the LDP method, chi square distance between the enrolled and input feature histograms is calculated. The calculated chi square distance is used as the score of fingerprint recognition. As the experimental results, the EER of the proposed approach is reduced by 0.521% in comparison with that of the previous LBP-based fingerprint recognition approach.

• Journal of the Korea Computer Industry Society
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• v.2 no.4
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• pp.417-424
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• 2001

Internet networks consisting of existing routers show the limits in efficiency of traffic managements. In order to overcome the limits, MPLS System is high speed switching technology and is not based on IP address but based on label was designed. However MPLS system being based on ATM has the difficulties of supporting Qos(Quality of Service). This paper suggested the way to consist a service-assured-network using CR-LDP protocol which was designed for guaranteeing QoS in MPLS system being based on ATM switch and using qGSMP protocol, and the way to implicitly establish LSP by implementing QoS Translation and QoS Mapping in LER System.

• Convergence Security Journal
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• v.14 no.5
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• pp.49-56
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• 2014

In this paper, we proposed a method for representing local facial features based on LDP (Local Directional Pattern). To represent both PFF (Permanent Facial Features) and TFF (Transient Facial Features) effectively, the proposed method configure local facial feature vectors based on overlapped blocks for each facial feature in the forms of various size and shape. There are three advantages - it take advantages of geometric feature based method; it shows robustness about detection error using movement characteristics of each facial feature; and it shows reduced sampling error because maintain spatial information caused by block size variability. Proposed method shows better classification accuracy and reduced amount of calculation than existing methods.