• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.5
• /
• pp.656-662
• /
• 2018

Pattern matching algorithm is widely used in many application fields such as bio-informatics, intrusion detection, etc. Among many string matching algorithms, KMP (Knuth-Morris-Pratt) algorithm is commonly used because of its fast execution time when using large texts. However, the processing speed of KMP algorithm is also limited when the text size increases significantly. In this paper, we propose a high throughput parallel KMP algorithm considering CPU-GPU memory hierarchy based on OpenCL in GPGPU (General Purpose computing on Graphic Processing Unit). We focus on the optimization for the allocation of work-times and work-groups, the local memory copy of the pattern data and the failure table, and the overlapping of the data transfer with the string matching operations. The experimental results show that the execution time of the optimized parallel KMP algorithm is about 3.6 times faster than that of the non-optimized parallel KMP algorithm.

• Journal of the Korean Institute of Rural Architecture
• /
• v.14 no.3
• /
• pp.109-119
• /
• 2012

This study aims to analyze architectural characteristics of railway station facilities which were built with development of railroads from Japanese Colonial Period to 1950's. To achieve this goals, 7 railway stations in Gyeongju area that are worth preserving were set up as research targets. For this study, I analyzed literature of the railway station and drawings which the KORAL Daegu Branch is keeping. Railway stations without a construction drawing investigated a direct visit. After analyzing the railway station facilities, the architectural properties such as plan, elevation and section have been identified. The results are as follows. First, Each modern railway station is usually consisted of waiting room and office, and ancillary spaces have been added. Over the years, however, the space was expanded horizontally. In that case, the structure and finish materials have been changed, like now. Second, Most of the roof shape is 'Matbae'(gable roof), especially Gyeongju station and Bulguksa Station are 'Woojingak roof. The roof structure is truss structure, especially as Pratt and Scissors type, but Gyeongju Station's structure is a reinforced concrete. Third, main doorway of waiting room is located in the center of the front gable. However, small stations like 'Ahwa' and 'Ipsil' station to ensure the passengers' waiting area are placed next to the office area.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.05a
• /
• pp.303-306
• /
• 2008

After the successful flight test of X-43A, U.S. Airforce is developing missile-type X-51A SED (Scramjet Engine Demonstrator-Wave Rider). X-51A using PWR (Pratt and Whitney Rocketdyne) X-1 hydrocarbon fueled scramjet engine will have a ground test in 2008 and flight test in 2009. Technologies established though the X-51A program will be transferred to DARPA's Falcon program developing HTV (Hypersonic Test Vehicle)-3X and HCV (Hypersonic Cruise Vehicle). Present paper is an overview of propulsion core technologies of X-51 such as regenerative cooling of engine structures and combustion using liquid/supercritical JP-7 fuel.

• The Journal of the Korea Contents Association
• /
• v.8 no.11
• /
• pp.41-48
• /
• 2008

This study focuses on the modeling file search engine and suggesting modified file search schema based on weight value using file contents in order to improve the performance in terms of search accuracy and matching time. Most of the file search engines have used string matching algorithms like KMP(Knuth.Morris.Pratt), which may limit portability and fast searching time. However, this kind of algorithms don't find exactly the files what you want. Hence, the file search engine based on weight value using file contents is proposed here in order to optimize the performance for mobile environments. The Comparison with previous research shows that the proposed schema provides better.

• Journal of Communications and Networks
• /
• v.4 no.4
• /
• pp.266-281
• /
• 2002

The General Packet Radio Service (GPRS) is being deployed by GSM network operators world-wide, and promises to provide users with “always-on” data access at bandwidths comparable to that of conventional fixed-wire telephone modems. However, many users have found the reality to be rather different, experiencing very disappointing performance when, for example, browsing the web over GPRS. In this paper, we examine the causes, and show how unfortunate interactions between the GPRS link characteristics and TCP/IP protocols lead to poor performance. A performance characterization of the GPRS link-layer is presented, determined through extensive measurements taken over production networks. We present measurements of packet loss rates, bandwidth availability, link stability, and round-trip time. The effect these characteristics have on TCP behavior are examined, demonstrating how they can result in poor link utilization, excessive packet queueing, and slow recovery from packet losses. Further, we show that the HTTP protocol can compound these issues, leading to dire WWW performance. We go on to show how the use of a transparent proxy interposed near the wired-wireless border can be used to alleviate many of these performance issues without requiring changes to either client or server end systems.

• Journal of the Korean Society of Costume
• /
• v.5
• /
• pp.237-246
• /
• 1981

This is a report of author's stay in the U.S. as an exchange scholar. During her stay from Dec. 1979 to Dec. 1980, she participated in costume studies at Pratt Institute, New York City and looked into materials of North Asian historical costumes. The author notes that the curriculum of costume studies in the U.S. place weight upon costume history, e.g., the master's program in costume studies of New York University requires 18 points in history courses out of 54 points required for the degree. The author also notes the leading role of the Costume Institute, the Metropolitan Museum of Arts in performing research works for the studies. As to the study of North Asian costumes, the author's work in the U.S. has been somewhat disappointing. She points out difficulties for a Korean researcher to access to basic materials which are scarce outside of China and Russia. She asserts, however, the comprehension of the history of North Asian costumes as a whole is essential to understand the characteristics of ancient Korean costumes. The author insists the costume history courses in Korean colleges are not appropriate as a apart of costume studies. Noting the costume education in the U.S. clearly aims at the training of costume professions, the author proposes the objective of costume education in Korea be redefined, and the teaching of "History of Korean Costumes" be reconstituted as to be suitable for it.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.42
• /
• pp.33.1-33.8
• /
• 2020

Background: We investigated the efficacy of a maxillary Jackson-Pratt (J-P) suction drain for preventing maxillary sinus hematoma and facial swelling after maxillary Le Fort I osteotomy (LF1). Methods: We retrospectively evaluated 66 patients who underwent LF1 at a single institution. Of these, 41 had a J-P suction tube inserted in the mandible and maxilla (maxillary insertion), and 25 had a J-P drain inserted in the mandible only (no maxillary insertion). Facial CT was obtained before and 4 days after surgery. We compared mean midfacial swelling and maxillary sinus haziness by t test and examined correlations between bleeding amount and body mass index (BMI). Results: For the maxillary-insertion group, the ratio of total maxillary sinus volume to haziness (57.5 ± 24.2%) was significantly lower than in the group without maxillary drain insertion (65.5% ± 20.3; P = .043). This latter group, however, did not have a significantly greater midfacial soft tissue volume (7575 mm³) than the maxillary-insertion group (7250 mm³; P = .728). BMI did not correlate significantly with bleeding amount or facial swelling. Conclusions: Suction drainage in the maxilla reduced maxillary sinus haziness after orthognathic surgery but did not significantly reduce midfacial swelling.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.27 no.2
• /
• pp.95-101
• /
• 2016

Background and Objectives : The main purpose of this study is to clarify perceptual and acoustic analysis for the patients with hypothyroidism after thyroidectomy especially focused on the characteristics of speech articulation with special reference to the consonant production. Materials and Methods : The subjects of the research were 40 male and female adults (males : 5, females : 35). They were all received radioactive iodine treatment which after total thyroidectomy. Voice samples were collected during the three stages of after surgery, pre-radioisotope treatment (RIT), and post-RIT. The acoustic analysis was conducted by using Pratt (ver.5.2.21) after measuring voice onset time (VOT). The subjective evaluation of the voices used CAPE-V. Results : A significant decrease in overall severity was displayed in the CAPE-V following RIT. It may be conjectured that this is connected to the change in voice following RIT. The loudness of the sound displayed a significant decrease in the CAPE-V following RIT. It is conjectured that this is connected to the decrease in vocal intensity following RIT. No statistically significant results were revealed for the comparative analysis on the voice onset time (VOT) in all plosives during the three periods. Conclusion : Perceptually, the overall severity of the voice with hypothyroidism was changed significantly before and after RIT. Eventhough VOT were not significantly changed, it tended to decrease VOT in patients with hypothyroidism.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.26 no.1
• /
• pp.40-45
• /
• 2015

Objectives:This study aims to investigate the correlation between the measurements of Praat as an acoustic evaluation and those of GRBAS and CAPE-V as perceptual rating tool respectively. Through this, it also tries to find out parameters to which attention should be paid when an evaluator, who is untrained in auditory-perceptual voice evaluation, conducts voice evaluation with objective tool. Materials and Methods:Voice samples of this study were 33 vocal polyp patients(23 males and 10 females) who visited our Department of Otorhinolaryngology. They sustained vowel voices of 'e' were recorded and acoustically analyzed. Results:As the results of correlation analysis between GRBAS and Praat measurements, G scale and R scale showed statistically significant correlation with Jitt, Shim and NHR. And it is found that B scale represented significant correlation with Jitt, S scale with Shim. As the results of analysis on correlation with CAPE-V and Praat measurements, OS scale and R scale showed statistically significant correlation with Jitt, Shim and NHR. B scale represented significant correlation with Jitt, S scale with Shim. Conclusion:Although, both GRBAS and CAPE-V were highly reliable, in comparison between CAPE-V and Pratt, more parameters that showed statistically significant correlation are observed, which implies that VAS has more potential to make detailed evaluation than ORD.

• Journal of Korean Association for Spatial Structures
• /
• v.1 no.1 s.1
• /
• pp.143-155
• /
• 2001

Generally, truss design has been determined by the designer's experience and intuition. But if we perform the most economical structural design we must consider not only cross-sections of members but also configurations(howe, warren and pratt types etc.) of single truss as the number of panel and truss height. The purpose of this study is to develope automated optimum design techniques for steel truss structures considering cross-sections of members and shape of trusses simultaneously. As the results, it could be possible to find easily the optimum solutions subject to design conditions at the preliminary structural design stage of the steel truss structures. In this study, the objective function is expressed as the whole member weight of trusses, and the applied constraints are as stresses, slenderness ratio, local buckling, deflection, member cross-sectional dimensions and truss height etc. The automated optimum design algorithm of this study is divided into three-level procedures. The first level on member cross-sectional optimization is performed by the sequential unconstrained minimization technique(SUMT) using dynamic programming method. And the second level about truss height optimization is applied for obtaining the optimum truss height by three-equal interval search method. The last level of optimization is applied for obtaining the optimum panel number of truss by integer programming method. The algorithm of multi-level optimization programming technique proposed in this study is more helpful for the economical design of plane trusses as well as space trusses.