Active Audit and Topology Adaptation in Unstructured P2P Overlay Networks

Park, Jun-Cheol Research Institute of Science and Technology HONGI 2005 Hongik Journal of Science and Technology Vol.9 No.-

To make a peer-to-peer(P2P) network free from selfish or malicious peers is a challenging task because of the flat, fully distributed, autonomous, and anonymous nature of such networks. In this paper, we focus on a peer's intentional act of dropping a relaying message, which is hard to be traced to its doer. We propose an audit and topology adaptation scheme to confine and weaken the ill effect from peers dropping messages on other peers in an unstructured P2P network. Using active network technologies, the scheme makes some routers with augmented capability assist the peers in adjusting their overlay connections. It uses a small set of basic primitives only and thus applies to all kinds of unstructured P2P networks. In fact, any legacy peer can execute the algorithm used in the scheme for its own gain by issuing a single query as if it were searching for a file. The scheme encourages the peers to comply with the protocol of the network, which leads to the improvement of service quality and peer satisfaction level. As preliminary results, a restricted usage pattern of the scheme is experimented using various metrics, which demonstrates the practicality of the approach.

間歇的 運動에 의한 脫水 및 水分攝取의 生理的 效果

朴哲浩,朴吉俊,李相于,金永明,朴贊熙,玄松子,呂南會,朴相甲,金榮俊 東亞大學校附設스포츠科學硏究所 1989 스포츠科學硏究論文集 Vol.7 No.-

This study aims at revealing the physiological responses of dehydration (DH) and rehydration (RH) in intermittent exercises at the work intensity of 70% HR max. First, with general student public, three times of exercise (each for 20 minutes) at the given work intensity were taken, with a break for 25 minutes respectively. Their heart rate, rectal temperature and plasma electrolyte concentration both DH and RH were measured. Second, in two groups of athletes and non-athletes, 9 rounds of exercise (for 100 minutes) and 8 breaks (for 60 minutes) were taken, with RH forced 10 times to compensate for the subjects' water loss. Their change in sweat loss and plasma electrolyte concentration as well as the IVDP(Intensive Voluntary dehydration Phenomenon) were experimented. The summary of this research follows. 1) Mean heart rate and rectal temperature in intermittent exercises were higher at DH than at RH, growing up at the increasing level of DH. 2) RH saw no change in the plasma concentration of Na+, K+ and Cl-, while DH observed a significant increase. 3) HCO₃made a significant decrease at DH before growing up. 4) Mg++ had no change, while Ca++ increased significantly at RH and DH. 5) Lactate showed an increase with significance at RH and DH, especially greater at DH. 6) Osmotic pressure increased meaningfully at DH. 7) Anion gap increased significantly at DH and RH. 8) On the other hand, when the forced RH was held, the group of athletes had greater sweat loss per body surface area than that of non-athletes. 9) The athletes' plasma concentration of Na+ and Cl- revealed a clear decrease. 10) There was seen no significant change in the plasma concentration of K+, Mg++ and Ca++ in both groups. 11) The IVDP occurred at the RH of 2.3ℓfor athletes and more than 2.5ℓfor no-athletes.

제 3 대구치 발치시 환자의 호흡 패턴이 스트레스 변화 양상에 미치는 영향

이상명,김형욱,박양호,김진철,박준우,이성준,안재목,Rhee, Sang-Myung,Kim, Hyung-Wook,Park, Yang-Ho,Kim, Jin-Cheol,Park, Jun-Woo,Rhee, Sung-Jun,Nyamdorj, Selenge,Ahn, Jae-Mok 대한구강악안면외과학회 2007 대한구강악안면외과학회지 Vol.33 No.5

Purpose: Heart rate variability(HRV) is the clinical consequence of various influences of the autonomic nervous system(ANS) on heart beat. HRV can estimate the potential physiologic rhythm from the interval between consecutive beats(RR interval or HRV data). It is known as RSA which represents respiration-related HR rhythmic oscillation. Previous studies demonstrated a specific breathing pattern(0.1Hz, 6breaths/min) to improve a physiological body condition related to the stress. In this paper, the level of stress would be evaluated in terms of three phases of the dental treatment, combined with 6breaths/min. Methods: These phases include before, during and after tooth extraction or anesthesia or something.36 patients' stresses were assessed using HRV stress analyzer in each phase in Kangdong Sacred Heart Hospital, and Chuncheon Sacred Heart Hospital, Hallym University Medical Center from Jun. to Sept. of 2007. HRV 5-min data collected were analyzed in time-domain and frequency-domain to evaluate the activity of autonomic nervous system(ANS) which represents the level of stress. Results: All HRV parameters including HF(high frequency), LF(low frequency) and LF/HF ratio showned a significant change affecting the ANS balance. There was a 6.4% difference between R(LF/HF)s on general breathing pattern for balance of Autonomic nervous system, but on controlled breathing pattern, 0.1Hz, was made narrow till 1.4%. The activity of ANS has increased by 1.4% on general breathing pattern, and by 2.9% on controlled breathing pattern, 0.1Hz. Conclusion: After analysis of preoperative stress changes and effect of breathing pattern of 0.1 Hz on the stress in 36 patients who have undergone third molar extraction, following was concluded. In the preoperative stage, the sympathetic change was the greatest?after the?anesthetic injection, and stress was relieved by controlling the breathing pattern to a frequency of 0.1Hz.

신성고혈압 흰쥐 대동맥 평활근에서 세포외 칼륨에 의한 혈관이완반응의 변이

전제열,염철호,윤평진,이정회,최형호,박유환,김진호 대한순환기학회 2000 Korean Circulation Journal Vol.30 No.8

태권도선수의 호흡순환능력에 관한 연구

박철호,김영준,김우규,박태열,홍명엽 東亞大學校附設스포츠科學硏究所 1999 스포츠科學硏究論文集 Vol.17 No.-

The purpose of this study was to evaluate the anaerobic thresold and EPOC(Excess post-exercise Oxygen Consumption) in treadmill exercise of taekwondo players(n=7),and group of controls college students(n=7). The started treadmill exercise with speed of 120m/min and within treadmill 5% slope. Especially the treadmill speed was increased with 20m/min per two minutes and subjects were finally led to exhaustion. The results obtained from this test were as follows: 1. The VO₂max( /min), VO₂ max(kg) showed significantly higher differences taekwondo group than control group in maximum exercise. 2. The ventilation volume showed significant difference taekwondo group than control group in maximum exercise. 3. The anaerobic threshold showed significant difference taekwondo group than control group in maximum exercise. 4. The EPOC showed significant difference taekwondo group than control group in maximum exercise.

고속주축 모니터링용 광파이버 변위센서의 레이저 다이오드 출력에 따른 성능평가

박찬규,신우철,홍준희,이동주 한국공작기계학회 2004 한국공작기계학회 춘계학술대회논문집 Vol.2004 No.-

This paper is to develop an optical fiber displacement sensor for monitoring high speed spindle. Proper magnitude of optical power as well as amplification of output signal are necessary to improve sensitivity of the sensor. In this paper, to meet the need of improvement of the sensor resolution, we choose proper optical power and amplification level through speculating on optical power of a laser diode.

충수염의 임상적 고찰과 초음파의 유용성

박정배,양혁준,김형수,황성연,박철완,이근 대한응급의학회 1995 대한응급의학회지 Vol.6 No.2

Appendicitis is the most common acute abdomen in Emergency Medical Center & outpatient department. But sometimes, it is difficult for us to diagnose because of clinically variable symptoms. We reviewed the ultrasonographic findings and analyse 521 cases of appendectomy patients about its distribution of sex and age, seasonal prevalence, clinical symptom and signs, laboratory findings, duration from onset of symptom to arrival at hospital, duration from arrival at hospital to operation, vital signs, operative results, and associated diseases, which were treated at the department of General Surgery & Emergency Medical Center in Chung Ang Gil Hospital from July, 1994 to June, 1995. The results were as follows : 1. The most common age group was second decade. And male to female ratio was 1.43:1. Seasonal variation was not significant. 2. Of 521 cases, 141 cases(27.1%) visited the hospital within 24 hours from the onset of symptom, and 259 cases(49.7%) visited between 24 to 48 hours. 3. In duration from arrival to operation, the cases within 6 hours were 263 (50.5%), the cases between 6 and 12 hours were 131(25..1%). 4. In systolic blood pressure, cases below 90mmHg were 19(3.6%), cases above 160mmHg were 23(4.4%). Below 60mmHg diastolic pressure were 55 cases(10.6%), cases above 110mmHg were 9(1.7%). In pulse rate, above 90 rate/min were 171(32.8%). 5. On admission leukocytosis was found in 413 cases(79.3%) and 342 cases of them were pathologic appendicitis. 6. Ultrasoundgraphy was performed in the 87 cases, but 23 cases were suggested appendicitis. Among 23 cases, 22(95.7%) revealed pathologic appendicitis at ooperation and labortatory examination. Of the 64 cases which were normal on ultrasonography, only 2 cases(3.1%) were proved to be appendicitis. 7. The results of 496 operations without ultrasonography were appendicitis in 390 cases(78.6%), mesenteric lymphadenopathy 36(7.3%), pelvic inflammatory disease 28(5.6%), fecalith 15(3.0%), terminal ileitis 8(1.6%), diverticulitis 7(1.4%), urinary tract stones 5(1.0%), cecal cancer 2 cases, right ovarian tumor 2 cases, tubo-ovarian abscess 2 cases, grater omentum internal hernia 1 case. Our results showed that the sensitivity of ultrasonohraphy was 95.8% and the specificity 98.4% in the diagnosis of appendicitis, It suggests that the ultrasonography is very helpful in the diagnosis & differential diagnosis of acute appeendiditis.

고속주축 모니터링용 광파이버 변위센서의 파이버 특성에 따른 센서 성능 연구

박찬규,신우철,배완성,홍준희,이동주 한국공작기계학회 2003 한국공작기계학회 추계학술대회논문집 Vol.2003 No.-

To make high speed spindle system work properly, sensors with outstanding resolution and dynamic characteristics are essential. An optical fiber displacement sensor is based on simple principles. Electrical signal responds to the optical flux change due to the displacement change between a target and a sensor probe. In this paper, the performance of optical fiber displacement sensor has been investigated according to properties of optical fiber. Firstly, optical loss has been measured before and after polishing optical fiber endface. Secondly, allowance of optical fiber bending has been tested. thirdly sensitivity and linear range of the sensor has been found out according to the shape of cross section of optical fiber.

방사화 분석법을 통한 방사선량 및 포획단면적 개념 이해

박상태,김용복,육근철,이희복,김준태,정기주 공주대학교 과학교육연구소 2003 과학교육연구 Vol.34 No.-

중성자 방사화법은 여러 가지 물질의 특성을 규명하는데 매우 유용한 방법이다. 기본적으로 이러한 방법은 매우 간단하다. 임의의 시료를 저속 중성자에 조사시키면, 그 시료는 방사능을 띄게 되고 시료로부터 나오는 β^+, β^-, 그리고 γ선의 선량을 측정하거나 시료의 반감기를 측정하면, 시료를 구성하고 있는 물질의 구성성분이나 그 농도를 알아낼 수 있다. 본 연구에서는 금 박막을 방사화시킴으로서 열중성자 선량값으로 1426.68 ± 11.62n/㎠ㆍsec를 얻었다. 또한, ^55Mn의 열중성자 포획 단면적은 13.79±0.45bam 이었는데 이는 Table of Isotope에 제시된 값과 매우 잘 일치하였다. 본 연구의 실험기법은 일반적으로 널리 알려진 방법이지만, 학생들이 쉽게 접할 수 있는 실험이 아니기 때문에 '선량' 또는 '단면적' 등돠 같은 물리 개념을 가르치는데 유용하게 사용될 수 있을 것으로 기대된다. Neutron activation is very powerful technique for identifying characteristics of many elements. Basically the technique is quite simple. A sample is irradiated by slow neutrons and becomes radioactive. By measuring the β^+s, β^-s, γs and half-life of the resulting sample, the elemental constituents of the sample and their relative concentrations can be identified. In this studies, thermal neutron flux was 1426.68 ± 11.62 n/㎠ ·sec from Au activation analysis. Thermal neutron capture cross section for ^55Mn was 13.79 ± 0.45 barn, it is a good agreement with Table of Isotope data. Technique of this measurement is not special, but can be used usefully for physics concepts learning such as flux and cross section.

스포츠·레저용품 구매행동에 관한 연구

박병주,노영태,이상봉,이영덕,전동호,박철준 釜山大學校 附設 體育科學硏究所 1997 體育科學硏究所 論文集 Vol.13 No.-

The decrease of working time and the increase of leisure time occused by the forms of Factory-Automation, Office-Automation and Household-Automation. The number of people involved in sports & leisure activities are world-widely increasing, and accordingly the demand of sports & leisure goods is outstandingly increased nowdays. In this regard, the main purpose of this study is to find out how the demand and desire of consumers are being formed by purchasing sports & leisure goods, to analysis major influencing consumers' purchasing activities by means of inspecting consumers' recogintion and attitude on sports & leisure goods. The following are results ; 1. In sports & leisure activity, this study is found out that 34 men(15.5%) play once in a week, 31(14.2%) play twice or thrice in a month, 29(13.3%) play twice or three in a week. But 31 women(14.2%) play twice or three in a month, 18(8.2%) play once in a week and 25(11.4%) never do it. 2. In use of purchasing goods, man in that to physical training 114(52.1%), to leisure 13(5.9%), etc 9(4.1%), women buy to leisure 75(34.3%), to physical training 5(2.3%), etc 3(1.3%). 3. The satisfied degrees of consumers is that man(3.82±0.7) is more than woman(2.86±0.7). 4. The determinant factors in purchasing is that woman is higher than, man in price, color, quality and design. But man is higher than woman in brand. 5. In improve method of sports and leisure goods, they answered in quality 113(51.6%), in design 66(30.2%), in price 16(7.3%), in brand 14(6.46%), in color 4(1.8%), etc 6(2.7%). 6. Information resources have mass media 52(23.7%), follow or friends 36(16.4%), show window or seller 21(9.6%). 7. The determinant factors of purchasing goods is 128(58.4%) in quality, 47(21.5%) in design, 37(16.9%) in color, 7(3.2%) in brand.