• Title/Summary/Keyword: DHT

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System Design for Range Search on P2P System based DHT (DHT 기반 P2P 시스템에서의 범위 검색을 위한 시스템 설계)

  • Han, Jong-Wook;Youm, Dea-Young;Han, Dong-Yun;Kim, Kyung-Suk
    • Proceedings of the Korea Information Processing Society Conference
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    • 2007.11a
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    • pp.982-985
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    • 2007
  • 인터넷의 보급과 PC의 발달로 정보의 분산과 공유가 가속화를 이루었고, 컴퓨팅 구조가 인터넷 기반으로 변화하였다. 이후 지금까지 수많은 시스템들이 클라이언트/서버 모델을 유지하고 있는 한편 대단위 분산 다중서버로 구성되는 환경이 출현하였다. 클라이언트/서버 모델에서 사용자들의 정보 공유의 제약을 해소하기 위해 개인의 피어 사이에 서로 공유하는 P2P(Peer-to-Peer) 패러다임이 출현 되었다. 하지만 기존의 DHT(Distributed Hash Table)를 기반으로 하는 P2P 시스템에선 정보를 검색할 때, 검색어와 검색결과의 모호성이 존재하고, 범위 검색을 지원하지 못하는 문제가 있었다. 우리는 이 문제를 해결할 한 가지 방안을 본 논문에서 제안한다.

Effective Heat Treatment Techniques for Control of Mung Bean Sprout Rot, Incorporable into Commercial Mass Production

  • Lee, Jung-Han;Han, Ki-Soo;Kim, Tae-Hyoung;Bae, Dong-Won;Kim, Dong-Kil;Kang, Jin-Ho;Kim, Hee-Kyu
    • The Plant Pathology Journal
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    • v.23 no.3
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    • pp.174-179
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    • 2007
  • Seedlot disinfection techniques to control mung bean sprout rot caused by Colletoricum acutatum and C. gloeosporioides were evaluated for commercial production scheme. Soaking seedlots in propolis (100 X) and ethanol (20% for 30 min) appeared promising with control values of 85.5 and 80.8 respectively, but still resulted in up to 20% rot incidence. None of the C. acutatum conidia survived through hot water immersion treatment (HWT) for 10 min at temperatures of 55, 60 and $65^{\circ}C$, whereas the effective range of the dry heat treatment (DHT) was $60-65^{\circ}C$. Tolerance of mung bean seedlot, as estimated by hypocotyl elongation and root growth, was lower for HWT than for DHT. Germination and growth of sprouts were excellent over the range of $55-65^{\circ}C\;at\;5^{\circ}C$ intervals, except for HWT at $65^{\circ}C$ for 5 min. At this marginal condition, heat damage appeared so that approximately 2% of seeds failed to sprout to normal germling and retarded sprouts were less than 5% with coarse wrinkled hypocotyls. These results suggested that DHT would be more feasible to disinfect mung bean seedlots for commercial sprout production. Heat treatment at above ranges was highly effective in eliminating the epiphytic bacterial strains associated with marketed sprout rot samples. HWT of seedlot at 55 and $60^{\circ}C$ for 5 min resulted in successful control of mung bean sprout rot incidence with marketable sprout quality. DHT at 60 and $65^{\circ}C$ for 30 min also gave good results through the small-scale sprouting system. Therefore, we optimized DHT scheme at 60 and $65^{\circ}C$ for 30 min, considering the practical value of seedlot disinfection with high precision and accuracy. This was further proved to be a feasible and reliable method against anthracnose incidence and those bacterial strains associated with marketed sprout rot samples as well, through factory scale mung bean sprout production system.

Inhibition of Proliferation of LNCaP Prostate Cells by Corni Fructus Extract Is Associated with a Decrease in the Expression of Benign Prostatic Hyperplasia-Causing Factors (산수유 추출물에 의한 LNCaP 전립선 세포의 증식 억제 및 양성 전립선 비대증 유발 인자의 발현에 미치는 영향)

  • Kim, Min Yeong;Ji, Seon Yeong;Hwangbo, Hyun;Lee, Hyesook;Hong, Su Hyun;Choi, Yung Hyun
    • Journal of Korean Medicine for Obesity Research
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    • v.21 no.1
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    • pp.10-21
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    • 2021
  • Objectives: Benign prostatic hyperplasia (BPH) is a progressive pathological condition characterized by excessive proliferation of the prostate. In this study, we evaluated the effect of Corni Fructus water extract (CF) on the promotion of prostate cell proliferation by dihydrotestosterone (DHT). Methods: The effect of CF on the proliferation of LNCaP prostate cells was evaluated, and DHT was treated to induce an in vitro BPH model. To study the mechanism of inhibition of cell proliferation and BPH by CF, changes in the expression of key factors related to cell cycle and BPH were investigated. We further investigated the effect on the production of reactive oxygen species (ROS) and nitric oxide (NO) to evaluate the antioxidant and anti-inflammatory efficacy of CF. Results: Inhibition of LNCaP cell proliferation by CF was associated with decreased expression of cyclin D1 and cyclin A and increased expression of cyclin-dependent kinase inhibitor p21. CF also suppressed expression of BPH inducing factors such as 5α-reductase type 2 and androgen receptor (AR) as well as prostate specific antigen (PSA). Furthermore, CF significantly blocked DHT-induced LNCaP cell proliferation and effectively attenuated DHT-induced expression of BPH mediators and cyclins. In addition, CF inhibited DHT-induced oxidative and inflammatory reactions by inhibiting production of ROS and NO. Conclusion: Our results demonstrated that CF probably acted as 5α-reductase type 2 inhibitor, preventing the 5α-reductase type 2-AR signaling pathway, thereby reducing the conversion of testosterone to DHT and the expression of PSA, which is at least correlated with the antioxidant and anti-inflammatory activities of CF.

An Adaptive Proximity Route Selection Method in DHT-Based Peer-to-Peer Systems (DHT 기반 피어-투-피어 시스템을 위한 적응적 근접경로 선택기법)

  • Song Ji-Young;Han Sae-Young;Park Sung-Yong
    • The KIPS Transactions:PartA
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    • v.13A no.1 s.98
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    • pp.11-18
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    • 2006
  • In the Internet of various networks, it is difficult to reduce real routing time by just minimizing their hop count. We propose an adaptive proximity route selection method in DHT-based peer-to-peer systems, in which nodes select the nぉe with smallest lookup latency among their routing table entries as a next routing node. Using Q-Routing algorithm and exponential recency-weighted average, each node estimates the total latency and establishes a lookup table. Moreover, without additional overhead, nodes exchange their lookup tables to update their routing tables. Several simulations measuring the lookup latencies and hop-to-hop latency show that our method outperforms the original Chord method as well as CFS' server selection method.

Architecture and Server Selection for DHT-based Distributed CDN (해시 테이블 기반 분산형 CDN 구조 및 서버 선택 방안)

  • Jung, Jong-Hae;Oh, Gun-Young;Lee, Nam-Kyung;Yoon, Chang-Woo;Lee, Hyun-Woo;Ryu, Won;Lee, Sung-Chang
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.5
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    • pp.217-228
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    • 2011
  • In centralize CDN systems, the content server selection is performed by service node for every user request, and the selected node is notified to the user. In this paper, we present distributed CDN architecture and algorithm in which the request from a user is delivered to the content source by a P2P algorithm utilizing DHT(distributed hash table) through the overlay network and the user selects one of the source nodes based on real-time user-centric criteria. For this purpose, we propose a modified Pastry algorithm for contents registration, search and selection, in addition to the distributed architecture. The proposed architecture has the advantages of load balancing, traffic balancing, scalability, fault-tolerance due to the self-configuration, self-healing attributes of distributed architecture. Various simulation shows the feasibility of the proposed architecture and algorithm, and the performance is compared and discussed for the variations of the proposed scheme.

Bolting Response of Various Lettuce Cultivars Affected by Seed Treatments (종자처리에 의한 상추 품종간 추대반응 차이)

  • Hwang, Hyeon-Jeong;Lee, Jung-Myung;An, Jong-Moon;Kim, Se-Young;Choi, Geun-Won
    • Korean Journal of Environmental Agriculture
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    • v.26 no.4
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    • pp.325-331
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    • 2007
  • A series of experiments were performed to evaluate effects of lettuce seed treatment with low temperature and dry heat treatment (DHT) on bolting response in the case of spring cultivation. During spring production in greenhouse, bolting response of the plants produced from the treated seeds was faster in the order of low temperature treatment, control and DHT. Plant height was increased 5-10 cm higher by low temperature treatment, but plant growth of some cultivars was inhibited by DHT. Difference on lettuce plant growth between low temperature treatment and DHT was gradually diminished with the lapse of time after transplanting. Fresh weight of plant was not significantly different among all treatments. 'Red Gyeolku' showed very early bolting response and plant height was significantly promoted by low temperature treatment. However, 'Cheongchima' showed low bolting percentage after various seed treatments, so it is considered late-bolting cultivar.

A Measurement Study of User Behavior and File Pollution in DHT-based P2P Networks (DHT 기반의 P2P 네트워크에서 사용자 행동양식 및 파일 오염에 관한 측정 연구)

  • Shin, Kyu-Yong;Yoo, Jin-Cheol;Lee, Jong-Deog
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.3
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    • pp.131-140
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    • 2011
  • File pollution (i.e., sharing of corrupted files, or contaminating index information with bogus index records) is a de facto problem in many file sharing Peer-to-Peer (P2P) systems in use today. Since pollution squanders network resources and frustrates users with unprofitable downloads (due to corrupted files) and unproductive download trials (due to bogus index records), the viability of P2P systems (and similar distributed information-sharing applications) is questionable unless properly addressed. Thus, developing effective anti-pollution mechanisms is an immediate problem in this literature. This paper provides useful information and deep insight with future researchers who want to design an effective anti-pollution mechanism throughout an extensive measurement study of user behavior and file pollution in a representative DHT-based P2P system, the Kad network.

Involvement of Serotonergic Mechanism in the Nucleus Tractus Solitarius for the Regulation of Blood Pressure and Heart Rate of Rats (흰쥐의 혈압 및 심박동수 조절에 대하여 Nucleus Tractus Solitarius 부위의 Serotonin성 기전의 역할)

  • Lee, Yong-Kyu;Hong, Ki-Whan;Yoon, Jae-Soon
    • The Korean Journal of Pharmacology
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    • v.25 no.1
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    • pp.1-11
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    • 1989
  • In this study, it was aimed to investigate the role of serotonergic neurotransmission in nucleus tractus solitarius (NTS) for the central regulation of blood pressure and heart rate and its involvement in baroreceptor reflex activation in rats. A microinjection of 5-hydroxytryptamine (5-HT) into the NTS produced decreases in blood pressure and heart rate. Maximal decreases were $34.4{\pm}1.6$ mmHg and $41.7{\pm}10.2$ beats per min by 300 pmol of 5-HT. Microinjections of ${\alpha}-methylnor-adrenaline$ $({\alpha}-MNE)$ and clonidine manifested similar decreases in blood pressure and heart rate. The hypotensive and bradycardial effects of 5-HT were blocked by previous applications of 5-HT antagonists, ritanserin, methysergide and ketanserin into the NTS, respectively. By pretreatment with reserpine and 6-hydroxydopamine (6-OHDA, i.c.v.), both hypotensive and bradycardial effects of 5-HT were significantly attenuated. Pretreatment with 5, 7-dihydroxytryptamine (5,7-DHT, i.c.v.) enhanced the hypotensive and bradycardial effects of 5-HT. Similarly, following pretreatment with 6-OHDA, the effects of clonidine were increased. Pretreatment either with 5,7-DHT or 6-OHDA significantly attenuated the sensitivity of baroreflex produced either by phenylephrine or by sodium nitroprusside. When either 5,7-DHT or 6-OHDA was injected into the NTS $(5,7-DHT;\;8{\mu}g\;6-OHDA;\;10{\mu}g)$, both of the baroreflex sensitivities were impaired. In the immunohistochemical study, the injection of 6-OHDA into the the NTS led to reduction of axon terminal varicosity, however, the injection did not reduce the numbers of catecholaminergic cell bodies. Likewise, when 5,7-DHT was injected into the NTS, the varicosity of serotonergic axon terminals was markedly reduced. Based on these results, it is suggested that (1) stimulation of serotonergic receptors in the NTS leads to decreases in blood pressure and heart rate as observed with the stimulation of catecholaminergic system, (2) both serotonergic and catecholaminergic receptors may be located postsynaptically, and (3) the serotonergic neurons as well as catecholaminergic neurons may have a close relevance for the activation of baroreflex.

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Effects of Schisandrae Fructus and Corni Fructus Extracts on the Proliferation and Expression of Prostatic Hyperplasia-inducing Factors in Dihydrotestosterone-stimulated LNCaP Human Prostate Carcinoma Cells (오미자와 산수유 추출물이 dihydrotestosterone가 처리된 LNCaP 인간 전립선 암세포의 증식 및 전립선 비대 유발 인자 발현에 미치는 영향)

  • Kim, Min Yeung;Ji, Seon Yeong;Hwangbo, Hyun;Lee, Hyesook;Kim, Tae Hee;Yoon, Seonhye;Kim, Hyun Jin;Kim, Sung Yeon;Kim, Tae Jung;Kim, Min Ji;Jung, Ha Eun;Choi, Yung Hyun
    • Journal of Life Science
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    • v.31 no.10
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    • pp.885-897
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    • 2021
  • Schisandrae Fructus (SF) and Corni Fructus (CF) have been used for a long time for the prevention and treatment of various diseases. Although reports have highlighted the possibility of inhibiting the onset and progression of benign prostatic hyperplasia (BPH), studies on related mechanisms are still lacking. In this study, we investigated the potential of SF and CF in improving BPH by using a dihydrotestosterone (DHT)-induced in vitro BPH model using LNCaP prostate carcinoma cells. According to our results, water and ethanol extracts of SF and CF significantly inhibited the proliferation of LNCaP cells by DHT treatment and markedly downregulated the expression of DHT-induced BPH biomarkers and growth factors. They also regulated the expression of apoptosis regulatory factors and significantly reduced DHT-mediated oxidative stress. In addition, the protective effect on major factors involved in the pathogenesis of BPH was more effective in the ethanol extract treatment group than in the water extract group. Furthermore, the improvement effect on BPH was higher in the 1:1 combined treatment group than in the ethanol extract alone treatment group of SF and CF, and 60% ethanol extracts showed a better effect than 40% ethanol extracts. Therefore, our findings demonstrate that SF and CF can protect against BPH by preventing the hyperproliferation of prostate cells through the inhibition of the androgen signaling pathway, which was correlated with their antioxidant activities. Therefore, SF and CF extracts may be useful in the clinical treatment of BPH, and the combination of these two extracts can be synergistic.