Multiple-Class Dynamic Threshold algorithm for Multimedia Traffic

김상윤,이성창,함진호,Kim, Sang-Yun,Lee, Sung-Chang,Ham, Jin-Ho The Institute of Electronics and Information Engin 2005 電子工學會論文誌-TC (Telecommunications) Vol.42 No.12

현재 사용되고 있는 Internet상의 트래픽은 어플리케이션의 종류에 따라 다양한 수준의 QoS 요구조건, 즉, Delay, Loss 그리고 Throughput성능에 대한 요구조건을 오청하고 있다. TCP protocol을 사용하는 ETP서비스나 E-Mail 등의 서비스는 Delay나 Loss 성능보다는 Throughput성능에 대한 요구가 높은 편이기 때문에 앞의 두 성능악화의 반대급부로서 Throughput성능을 보장받곤 한다. 반면에, 대부분 UDP protocol을 사용하는 real-time streaming 어플리케이션, 예를 들면, IP telephony, Video conferencing, 혹은 network games등의 어플리케이션은 여타의 것들에 비하여 Throughput 보다는 delay나 loss에 대한 성능을 상대적으로 높게 요구한다. 하지만 현재의 AQM들은 best-effort 서비스에 초점을 맞추고 있다. 즉, throughput 성능을 위하여 delay나 loss성능을 희생하고 있기 때문에 다양한 어플리케이션에 적합한 서비스를 제공하기 힘들다. 따라서 본 논문에서는 각 어플리케이션이 필요로 하는 QoS 성능을 고려하여 어플리케이션들을 세 가지 클래스로 분류한 뒤 적합한 QoS 요구조건을 고려한 새로운 AQM 알고리즘을 제안한 뒤, 시뮬레이션을 통하여 다른 AQM 알고리즘과 비교 분석하고 그에 대한 결론을 도출한다. Traditional Internet applications such as FIP and E-mail are increasingly sharing bandwidth with newer, more demanding applications such as Web browsing, IP telephony, video conference and online games. These new applications require Quality of Service (QoS), in terms of delay, loss and throughput that are different from QoS requirements of traditional applications. Unfortunately, current Active Queue Management (AQM) approaches offer monolithic best-effort service to all Internet applications regardless of the current QoS requirements. This paper proposes and evaluates a new AQM technique, called MCDT that provides dynamic and separated buffer threshold for each Applications, those are FTP and e-mail on TCP traffic, streaming services on tagged UDP traffic, and the other services on untagged UDP traffic. Using a new QoS metric, our simulations demonstrate that MCDT yields higher QoS in terms of the delay variation and a packet loss than RED when there are heavy UDP traffics that include streaming applications and data applications. MCDT fits the current best-effort Internet environment without high complexity.

백룡동굴 종유관의 연간 성장 특성과 조절 요인에 대한 모니터링 연구결과

김상윤(Sang-Yun Kim),조경남(Kyoung-Nam Jo) 대한지질학회 2021 대한지질학회 학술대회 Vol.2021 No.10

다양한 탄산염 동굴생성물의 연간 성장(annual growth) 특성은 연대학적 및 고기후학적 증거를 제공하는 가장 기본적인 특징 중 하나로 여겨져 왔다. 지금까지 동굴생성물의 연간 성장에 대한 연구는 주로 우라늄 계열 연대측정 결과와의 교차 검증과 미량원소 등 지화학 데이터와의 비교분석을 바탕으로 수행되었다. 하지만 동굴생성물의 연간 성장에 대한 이해는 도출된 실험 결과의 본질적인 오류 때문에 여전히 다년간의 간접적 증거에 기초하고 있다. 이 연구에서는 4년간 월 단위로 기록한 다양한 인자(동굴 대기 CO₂, 동굴수 Ca<SUP>2+</SUP>, 낙수율 등)를 활용하여 강원도 평창군 소재 백룡동굴의 종유관의 연간 성장 특성을 확정하고자 하였다. 이번 연구결과는 종유관이 연간 1 mm/year 미만의 성장률을 보이는 것으로 나타났으며, 성장띠(growth band)가 관찰되는 종유관에서는 1년에 한 층씩 형성되는 것을 확인하였다. 특히, 3년간 동일하게 대부분의 성장이 집중되는 시기는 건기(10~5월)에 해당하며, 성장선(growth laminae)은 우기(6~9월)에 형성되는 것으로 나타났다. 동굴생성물의 성장을 조절하는 여러 요인들과의 비교에 의하면 동굴 대기순환(cave ventilation)으로 인한 이산화탄소의 계절적 변화가 종유관의 성장에 중요한 조절요인으로 판단된다. 이번 연구의 결과는 성장선이 나타나는 국내 동굴생성물의 주 성장요인으로 동굴 대기 이산화탄소 농도가 주요하게 영향을 끼칠 수 있음을 지시한다. 또한, 동굴생성물의 다양한 프록시를 활용한 고기후학적 해석에 있어 이론적 최대 해상도를 설정하는 데에도 매우 중요한 의미를 지닌다.

공동주택 옥상의 파라펫 일체형 소형풍력발전기(PSWP) 적용을 위한 기류분석

김상윤(Kim, Sang-Yun),이용호(Lee, Yong-Ho),황정하(Hwang, Jung-Ha) 한국건축친환경설비학회 2017 한국건축친환경설비학회 논문집 Vol.11 No.3

Being an experimental study of CFD simulation and air current measurement for application of PSWP generators on the rooftop of apartment buildings, this research developed urban wind power resources based on the wind speed data for the recent decade by Daegu’s Branch Office of Meteorology and designed and manufactured a PSWP module according to the current status of arrangements and rooftop parapets of apartment buildings and CFD simulation. It developed a method to optimize the efficiency of PSWP generators by creating the same outside air condition as the rooftop of apartment buildings and measuring air currents according to outside air velocity, wind direction change and PSWP installation condition. The results of the experiment according to outside air velocity, parapet distance, the percentage of perforated sheet, angle of guide vane, extension height of parapet and generator arrangement are as follows: For variable installations of generators for changes in outside air environment, outside air velocity over 5.0<SUP>m</SUP>/s and parapet, a distance of less than 0.5m is required to secure operating wind speed more than 3.0<SUP>m</SUP>/s; if the distance is over 0.5m, the height of parapet needs to be increased. When it comes to wind speed by wind direction, frontal winds are more advantageous than crosswinds; accordingly, as for the percentage of perforated sheet, an enclosed structure is favorable. For wind speed by guide vane angle, a horizontal angle to the wind direction (0°) is better. Also, the highest extension of parapet support, 0.45m, is more advantageous. For a single arrangement of a generator, the top of the parapet is effective, while the top of the front and the middle of the back are the most favorable for a double arrangement

Temperature Sensor 기반 ±1 % 이내의 주파수 정확도를 가지는 18 MHz Relaxation Oscillator의 설계

김상윤(Sang Yun Kim),이주리(Ju ri Lee),이동수(Dong Soo Lee),박형구(Hyung Gu Park),김홍진(Hong Jin Kim),이강윤(Kang-Yoon Lee) 한국산업정보학회 2013 한국산업정보학회논문지 Vol.18 No.5

본 논문에서는 BGR과 ADC를 사용하여 Temperature Compensation 기능을 가진 Relaxation Oscillator를 제안한다. Relaxation Oscillator는 전류조절을 통해 주파수를 결정한다. 제안하는 Relaxation Oscillator는 온도에 따른 출력 주파수를 보상하기 위하여 온도에 따른 ADC 및 BGR의 출력 코드를 사용하여 전류를 조절한다. 제안하는 Relaxation Oscillator는 CMOS 0.35 μm 공정으로 설계되었으며, 면적은 240 μm x 210 μm 이다. 전류 소모는 공급전압인 5 V에서 600 μA이며, 온도에 대한 출력 주파수는 ±1 %이내의 정확도를 가진다. In this paper, a Relaxation Oscillator with temperature compensation using BGR and ADC is presented. The current to determine the frequency of Relaxation Oscillator can be controlled. By adjusting the current according to the temperature using the code that is output from the ADC and BGR, was to compensate the output frequency of the temperature. It is fabricated in a 0.35 μm CMOS process with an active area of 240 μm x 210 μm. Current consumption is 600 μA from a 5 V and the rate of change of the output frequency with temperature shows about ±1 %.

유연 탄산칼슘을 사용한 종이의 칼렌다링 효과

김상윤(Sang Yun Kim),한정수(Jung Soo Han),정선영(Sun young Jung),서영범(Yung Bum Seo) 한국펄프·종이공학회 2020 한국펄프·종이공학회 학술발표논문집 Vol.2020 No.10

시간 영역에서의 제한된 절점력을 이용한 구조물의 손상검출

김상윤 ( Kim Sang Yun ),유석형 ( Yoo Sukhyeong ),신성우 ( Shin Sung Woo ) 한국구조물진단유지관리공학회 2007 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.11 No.2

Numerous non-destructive tests(NDT) to assess the safety of real structures have been developed. System identification(SI) techniques using dynamic responses and behaviors of structural systems become an outstanding issue of researchers. However the conventional SI techniques are identified to be non-practical to the complex and tall buildings, due to limitation of the availability of an accurate data that is magnitude or location of external loads. Thus a technique to estimate structural properties of building without input measurement data and using limited response is essential in structural health monitoring. In this study, shaking table tests on three-story plane frame steel structures were performed. Out-put only model analysis on the measured data was performed, and the dynamic properties were inverse analyzed using least square method in time domain. In results damage detection was performed in each member level, which was performed at story level in conventional SI techniques of frequency domain.

가전 제품의 디지털 네트워크화에 따른 방향 예측 연구

김상윤(KIM Sang-yun),한승아(HAN Seoung-a),민규홍(MIN Kyu-hong),김철수(KIM Chul-su),김철호(KIM Chul-ho) 한국디자인학회 2000 디자인학연구 Vol.- No.38

경북지역 가축에서 Salmonella속 균 감염증에 대한 역학적 특성

김상윤 ( Sang Yun Kim ),이희무 ( Hee Moo Lee ),김신 ( Sin Kim ),홍현표 ( Hyon Pyo Hong ),권헌일 ( Heon Il Kwon ) 한국동물위생학회 2001 한국동물위생학회지 (KOJVS) Vol.24 No.1

The result of studying the epidemiological characteristics of Salmonella strains which have been isolated from the domestic animals in Gyeongbuk province from February 1998 to August 2000 were summarized as follows. The isolation rates of Salmonella strains were 2.0% from cattle feces, 6.3% from cattle lymph node, 9.5% from pig feces, and 25.1% from pig lymph node. In poultry, the isolation rates were 30.3%. The isolates of Salmonella showed positive reaction for MUCAP test, methyl red test, but showed negative reaction for urea test, indole test, Voges Proskauer test. On TSI agar, the isolates showed acid butt, alkaline slant. Also, the isolates were identified as Salmonella strain by API 20E kit. Non H2S production Salmonella strains isolated from poultry were identified as S gallinarum. As a result of serotyping, B group were the most common in cattle and pig, D1 in chickens. 21 serovars were found. The common serovar from the domestic animals was S typhimurium, S derby, S agona, S schwarzenground, S enteritidis and S gallinarum. The most commonly encountered serovars in cattle were S agona and S typhimurium in pig, S gallinarum in chicken. As a result of antimicrobial susceptibility test, all Salmonella isolates were susceptible to amikacin, ciprofloxacin. Norfloxacin, cefotaxime and polymycin B. The resistance rates to tetracycline and streptomycin was 58% and 56% respectively. 69.3% of all isolates were resistant to more than one antimicrobial agent. Out of the resistant isolates, the isolates resistant to streptomycin and tetracycline was 36%. There were 24 strains of multiresistant isolates resistant to more than 5 antimicrobial agents. S typhimurium were resistant to all antimicrobial agents, also had a lot of multiresistant strains. Therefore, S typhimurium was considered as a major agent of antimicrobial resistance.

경북지역 가축에서 분리된 Salmonella typhimurium과 S enteritidis의 phage typing 및 pulsed-field gel electrophoresis

김상윤 ( Sang Yun Kim ),이희무 ( Hee Moo Lee ),김신 ( Sin Kim ),홍현표 ( Hyon Pyo Hong ),권헌일 ( Heon Il Kwon ) 한국동물위생학회 2001 한국동물위생학회지 (KOJVS) Vol.24 No.3

Forty-five Salmonella typhimurium isolates were encountered 8 phage types in which DT197 and U302 were the predominant types. The DT104 type which was first found from pig in Korea, and was resistant to chloramphenicol, streptomycin, sulfamethoxazole/trimethoprim, tetracycline, gentamicin and nalidixic acid. Twenty-two S enteritidis isolates were encountered 5 phage types in which PT4 were the representative (predominant). S enteritidis isolates were susceptible to all antimicrobial agents. As a result of PFGE analysis for S typhimurium and 5 enteritidis, PFGE patterns was better than phage typing in discriminating of strains. PFGE patterns were not in accord with phage type even though some strain had the same phage types.

원자력시설의 콘크리트 앵커시스템 규제요건

김상윤(Sang-Yun Kim),이재하(Jae-Ha Lee) 한국콘크리트학회 2011 콘크리트학회지 Vol.23 No.4