• Journal of the Institute of Convergence Signal Processing
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• v.4 no.1
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• pp.9-14
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• 2003

APON, the subscriber network using bus or tree topology, requires MAC protocol, because it shares the uplink channel for many subscribers to transmit data to OLT. Although various MAC schemes, which consider each QoS characteristics of traffic are proposed considering transmission characteristics of ATM traffic class, existing schemes reduce the network efficiency by increasing transmission overhead in frame. In this paper, we propose new MAC scheme, which shows similar performance as those of existing schemes but does not increase transmission overhead. To prevent increasing transmission overhead, the proposed scheme encodes the information about each cell information of traffic of the local queue in RAU transmitted periodically from ONU to OLT Thus, the proposed MAC scheme shows similar performance as those of existing ones and increases efficiency of entire network.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.389-390
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• 2006

Selective surface densification is a tool for improving the mechanical properties of PM steels, such that the requirements for highly loaded gears can be matched. This paper describes the manufacturing and the properties of a helical P/M gear. The gear performance was evaluated on a 3-shaft back to back test rig, on a load bearing test rig and on a sound test bench. The results of these tests are presented and compared to data obtained from solid steel gear with identical geometry and surface quality. This comparison indicates that P/M gears have a load bearing capacity and noise level which are both well comparable to solid steel gears.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.2
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• pp.136-140
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• 2004

Twenty-one lowland rice genotypes were evaluated for their stability parameters with respect to grain yield in a multi locational trial at five different sites of Eastern India viz. CRRI, Cuttack (Orissa); OUAT, Bhubaneswar (Orissa); CRS, Masodha (UP); RAU, Pusa (Bihar) and RARS, North Lakhimpur (Assam). Pooled analysis of variance reflects existence of genotype x environment interactions and contribution of both linear and nonlinear components to genotype (G) x environment (E) interactions. Through stability parameter analysis it was found that Rayda $\textrm{B}_3$, CR 778-95 and CR 661-236 were suitable for over all environments where as Sabita, OR 1334-16 and OR 1358-RGA-4 were suitable for rich environments. PSR 1209-2-3-2, CR 780-1937, Ambika, OR 877-ST-4-2 and CR 662-2211 were identified for poor environments.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.687-689
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• 2003

High resolution satellite images have huge amount of pixels in common. Thus, an efficient method is required for the generation of orthoimages. Patch backprojection method is a feasible way to improve the efficiency with respect to the point-by-point patch backprojection. We will propose an Adaptive Patch that optimizes the patch size for different terrain variations. The essence of the patch optimization is quadrate structuring for terrain variations. The area of interest is, thus, sequentially subdivided to four quadrate tiles until a preset criterion is met. The experiment results indicated that the proposed method is efficient without losing accuracy.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.57-59
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• 2003

Digital surface model generation from IKONOS stereo imagery is a new challenge in photogrammetric community, especially when the satellite company does not provide the raw data as well as their ancillary ephemeris data. In this paper we utilized an estimated relief displacement azimuth and the nominal collection elevation data included in the metadata file to correct the relief displacement of GCPs, together with a linear transformation for geometric modeling of IKONOS imagery. Space intersection is performed by the trigonometric intersection assuming a parallel projection of IKONOS imagery due to its small FOV and frame size. In the experiment, less than 2-meters of RMSE in orbit modeling is achieved denoting the potential positioning accuracy of the IKONOS stereo imagery.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.773-775
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• 2003

From the view point of data fusion, we integrate LIDAR data and digital aerial images to perform 3D building modeling in this study. The proposed scheme comprises two major parts: (1) building block extraction and (2) building model reconstruction. In the first step, height differences are analyzed to detect the above ground areas. Color analysis is then performed for the exclusion of tree areas. Potential building blocks are selected first followed by the refinement of building areas. In the second step, through edge detection and extracting the height information from LIDAR data, accurate 3D edges in object space is calculated. The accurate 3D edges are combined with the already developed SMS method for building modeling. LIDAR data acquired by Leica ALS 40 in Hsin-Chu Science-based Industrial Park of north Taiwan will be used in the test.

• Journal of Oral Medicine and Pain
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• v.33 no.2
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• pp.133-145
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• 2008

The purpose of this study was to investigate the taste sensitivity in patients with oral mucosal diseases(Oral lichen planus(OLP), Recurrent apthous ulcer(RAU)) using electrogustometer. One hundred and seventy three subjects were included for the study and they were categorized into 2 groups(control 100, patient 73) and patient group was investigated in the Department of Oral Medicine, Pusan National University Hospital from April, 2005 until January, 2007. Control group was investigated in the clinics at Inchen Metroplitan city and Cheongju city from February to August, 2006. The electrical taste thresholds were measured by using an electrogustometer for the 4 different sites(tongue tip, tongue lateral, circumvallate papilla and soft palate) in oral cavity. The results were as follows ; 1. The electrical taste threshold in patient group was significantly decreased than that in the control group(p<0.001). 2. The electrical taste threshold, in terms of the chronicity and lesion multiplicity, was not significantly changed in patient group. 3. The electrical taste threshold was not significantly changed in Dexan only and Dexan+Prs combination treated group. 4. The electrical taste threshold, in terms of treatment progress(no response vs half response vs complete response), was not significantly changed. However subjective index which was determined by NAS(Numerical Analogy Scale) was significantly increased in no response group but significantly decreased in complete response group(p<0.001)

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.1
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• pp.12-22
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• 2000

This paper presents the window-based permit distribution scheme for efficient medium access control to support multiclass traffic in APON(ATM over passive optical network). The proposed MAC protocol considers the characteristics of QoS(Quality of Service) for various traffic classes. A periodic RAU(request access unit) in upstream direction, includes dedicative request fields for each traffic category within the request slot. The transmission of upstream cell is permitted by the proposed window-based spacing scheme which distributes the requested traffic into several segments in the unit of one spacing window. The delay sensitive traffic source such as CBR or VBR with the stringent requirements on CDV and delay, is allocated prior to any other class. In order to reduce the CDV, so that the permit arrival rate close to the cell arrival rate, Running-Window algorithm is applied to permit distribution processing for these classes. The ABR traffic, which has not-strict CDV or delay criteria, is allocated flexibly to the residual bandwidth in FIFO manner. UBR traffic is allocated with the lowest priority for the remaining capacity. The performance of proposed protocol is evaluated in terms of transfer delay and 1-point CDV according to various offered load. The simulation results show that our protocol has the prominent improvement on CDV and delay performance with compared to the previous protocol.

• Korean Journal of Radiology
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• v.24 no.10
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• pp.1006-1016
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• 2023

Objective: Computed tomography (CT) is an established method for the diagnosis, staging, and treatment of multiple myeloma. Here, we investigated the potential of photon-counting detector computed tomography (PCD-CT) in terms of image quality, diagnostic confidence, and radiation dose compared with energy-integrating detector CT (EID-CT). Materials and Methods: In this prospective study, patients with known multiple myeloma underwent clinically indicated whole-body PCD-CT. The image quality of PCD-CT was assessed qualitatively by three independent radiologists for overall image quality, edge sharpness, image noise, lesion conspicuity, and diagnostic confidence using a 5-point Likert scale (5 = excellent), and quantitatively for signal homogeneity using the coefficient of variation (CV) of Hounsfield Units (HU) values and modulation transfer function (MTF) via the full width at half maximum (FWHM) in the frequency space. The results were compared with those of the current clinical standard EID-CT protocols as controls. Additionally, the radiation dose (CTDIvol) was determined. Results: We enrolled 35 patients with multiple myeloma (mean age 69.8 ± 9.1 years; 18 [51%] males). Qualitative image analysis revealed superior scores (median [interquartile range]) for PCD-CT regarding overall image quality (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]), edge sharpness (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]), image noise (4.0 [4.0-4.0] vs. 3.0 [3.0-4.0]), lesion conspicuity (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]), and diagnostic confidence (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]) compared with EID-CT (P ≤ 0.004). In quantitative image analyses, PCD-CT compared with EID-CT revealed a substantially lower FWHM (2.89 vs. 25.68 cy/pixel) and a significantly more homogeneous signal (mean CV ± standard deviation [SD], 0.99 ± 0.65 vs. 1.66 ± 0.5; P < 0.001) at a significantly lower radiation dose (mean CTDIvol ± SD, 3.33 ± 0.82 vs. 7.19 ± 3.57 mGy; P < 0.001). Conclusion: Whole-body PCD-CT provides significantly higher subjective and objective image quality at significantly reduced radiation doses than the current clinical standard EID-CT protocols, along with readily available multi-spectral data, facilitating the potential for further advanced post-processing.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.4
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• pp.239-246
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• 2013

Global restaurant franchises are becoming more and more popular in China, Japan, and South Korea. Understanding target customers' needs for restaurant franchises is considered one of the most important factors for their business success. In this study, four domains-food-related domain (FRD), interior-related domain (IRD), staff-related domain (SRD), and convenience-related domain (CRD)-and 24 elements were classified. A survey with 450 respondents in the three capital cities (Beijing, Tokyo, and Seoul) was then conducted to examine the effect of the factors influencing customer satisfaction. After statistical analysis, thirteen main elements were found as factors influencing customer satisfaction. The analysis result showed that the food-related domain (FRD) was the most important in Beijing. The interior-related domain (IRD) and the convenience-related domain (CRD) were considered the most important in Tokyo and Seoul. Some cultural differences in customer satisfaction were also found. The results provide a guideline for better customer experience management of a restaurant franchise in the three cities.