• Title/Summary/Keyword: Selective Search

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Studies on the Selectivity of the Herbicide Alachlor;II. A Metabolic Approach to Selectivity (제초제 Alachlor 의 선택성에 관한 연구;II. 대사론적 접근)

  • Hwang, Eul-Chul;Park, Chang-Kyu
    • Korean Journal of Environmental Agriculture
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    • v.13 no.2
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    • pp.209-215
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    • 1994
  • Absorption, translocation, and metabolism of the herbicide alachlor in soybean, Chinese cabbage, and barnyard grass seedlings were examined and compared with each other using [phenyl-U-$^{14}C$] alachlor in search of a primary factor contributing to the selectivity of alachlor. When root of each seedling was immersed into the solution containing [$^{14}C$]alachlor, the amount of absorbed radioactivity/mg dry matter of seedling which was suggested to be correlated with the susceptibility of plants to alachlor decreased in the order of soybean ${\gg}$ Chinese cabbage ${\geq}$ barnyard grass and the rate of translocation to shoot was Chinese cabbage ${\geq}$ barnyard grass ${\gg}$ soybean. These orders did not consistently explain the selective phytotoxicity of alachlor. Analyses of extracts by reverse phase chromatography showed that alachlor was detoxified by conjugation with glutathione in all three plants and the rate of glutathione conjugation of soybean, the resistant species to alachlor, was the greatest, while that of barnyard grass, the susceptible, was the lowest among three plants. This result explained well the selective phytotoxicity of alachlor. Both absorption and translocation contribute undoubtedly to the selectivity by influencing the active internal concentration of alachlor. However, neither of them appeared to be a primary factor. It was concluded that the most important primary factor was the rate of glutathione conjugation, which detoxifies alachlor and plays an important role in selectivity.

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Screening of Cyclooxygenase-2 (COX-2) Inhibitors from Natural Products (천연물로부터 사이클로옥시게나제-2 저해제 검색)

  • Moon, Tae-Chul;Chung, Kyu-Charn;Son, Kun-Ho;Kim, Hyun-Pyo;Kang, Sam-Sik;Chang, Hyeun-Wook
    • YAKHAK HOEJI
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    • v.42 no.2
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    • pp.214-219
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    • 1998
  • Tissue distributions and association of cyclooxygenase-2 (COX-2) with inflammatory have led us to search for COX-2 selective inhibitors from natural products. Conceptually, COX- 2 selective inhibitors should be expected to retain anti-inflammatory efficacy by inhibition of PGs production while reducing or eliminating the gastric, renal and hemostatic side effects commonly associated with NSAIDs use. Thus, a logical approach to the treatment of inflammatory diseases should involve the inhibitors of COX-2. To develop new COX-2 inhibitors from natural products, two hundred crude drugs were screened by inhibiting PGD2 generation in bone marrow derived mast cells (BMMC). Among them, 6 methanol extracts of crude drugs such as, Bletillae rhizoma, Aconiti kgreani rhizoma, Belamcandae rhizoma, Nelumbinis semen, Gleniae radix, Aurantii immatri pericarpium inhibited more than 85% of BMMC COX-2 activity at a concentration 2.5${\mu}$g/ml.

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In Search of a Definition of Successful Aging: A Review of Literature (성공적인 노화 정의를 위한 문헌연구)

  • 홍현방;최혜경
    • Journal of Families and Better Life
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    • v.21 no.2
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    • pp.145-154
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    • 2003
  • As the life-expectancy is ever-increasing, and the proportion of the elderly population is growing steadily in every society of the world, it is ever more important to establish what factors allow certain elderly people to age successfully and remain relatively independent while others grow old less successfully and require extensive intervention. However, there is no consensus yet as to what successful aging means. Researchers have defined successful aging in a variety of ways. This study attempted to define the concept of successful aging and to clarify some dimensions of it through literature review. Previous approaches of studying successful aging and related themes were examined. Early perspectives including activity, disengagement, and continuity theories, Selective Optimization with Compensation (SOC) model by Baltes and Baltes, three different conceptions of successful aging, that is, psychological well-being, physical health, and wisdom, and MacArthur research on successful aging have been reviewed for this study. The definition derived from the review is: Keeping up continuous developmental processes to achieve wisdom or ego-integrity, without suffering any major disabilities in either physical or mental functioning, while maintaining psychological well-being and employing SOC strategies, and participating in positive relationships with significant others. The dimensions of successful aging are 1) personal resources, including physical health, cognitive competences, self esteem, and social support 2) adaptation process of SOC, and 3) psychological aspects, including psychological well-being and wisdom.

A Study on Motion Estimator Design Using DCT DC Value (DCT 직류 값을 이용한 움직임 추정기 설계에 관한 연구)

  • Lee, Gwon-Cheol;Park, Jong-Jin;Jo, Won-Gyeong
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.38 no.3
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    • pp.258-268
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    • 2001
  • The compression method is necessarily used to send the high quality moving picture that contains a number of data in image processing. In the field of moving picture compression method, the motion estimation algorithm is used to reduce the temporal redundancy. Block matching algorithm to be usually used is distinguished partial search algorithm with full search algorithm. Full search algorithm be used in this paper is the method to compare the reference block with entire block in the search window. It is very efficient and has simple data flow and control circuit. But the bigger the search window, the larger hardware size, because large computational operation is needed. In this paper, we design the full search block matching motion estimator. Using the DCT DC values, we decide luminance. And we apply 3 bit compare-selector using bit plane to I(Intra coded) picture, not using 8 bit luminance signals. Also it is suggested that use the same selective bit for the P(Predicted coded) and B(Bidirectional coded) picture. We compare based full search method with PSNR(Peak Signal to Noise Ratio) for C language modeling. Its condition is the reference block 8$\times$8, the search window 24$\times$24 and 352$\times$288 gray scale standard video images. The result has small difference that we cannot see. And we design the suggested motion estimator that hardware size is proved to reduce 38.3% for structure I and 30.7% for structure II. The memory is proved to reduce 31.3% for structure I and II.

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Performance Analysis of DMF Acquisition System in Frequency-Selective Rayleigh Fading Channel (주파수 선택적 레일리 페이딩 채널에서의 DMF 초기동기 장치의 성능분석)

  • 김성철;이연우;조춘근;박형근;차균현
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.7B
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    • pp.1351-1360
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    • 1999
  • In frequency selective channels, conventional PN code acquisition schemes are not ideal candidates. This is because they are primarily designed for the AWGN channel. In this paper, a direct-sequence spread-spectrum(DSSS) PN code acquisition system based on digital matched filtering (DMF) with automatic threshold control(ATC) algorithm is presented and analyzed with regards to probability of detection and probability of false alarm. These two important probabilities, the probability of detection ($P_D$) and the probability of false alarm ($P_{FA}$) are derived and analyzed in considering Doppler shift, sampling rate, mean acquisition time, and PN chip rate in frequency selective Rayleigh fading channel when using serial-search method as detection technique. From computer simulation results of a DMF acquisition system model, it is shown that the performance of the acquisition system using ATC algorithm is better than that of constant threshold system.

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Paroxetine, as an Adjuvant Analgesic for the Management of Neuropathic Pain Syndrome (신경병증성 통증 증후군의 관리를 위한 부가적 진통제로서의 Paroxetine)

  • Han, Tae-Hyung;Eun, Jong-Shin;Lee, Sang-Min;Shin, Baek-Hyo
    • The Korean Journal of Pain
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    • v.11 no.2
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    • pp.201-209
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    • 1998
  • Background: Tricyclic antidepressants (TCA) have been used for various pain syndromes for their analgesic effects. They, however, often have anticholinergic side effects and therefore search for more selective drugs with fewer side effects is justified. Paroxetine, a selective serotonin reuptake inhibitor devoid of autonomic side effects, was evaluated for its role as an analgesic adjuvant in the management of neuropathic pain. Method: According to individual diagnostic group as diabetic neuropathy, postherpetic neuralgia, central pain syndrome and cancer related plexopathy, 10 patients per each group were equally accumulated. Patients have been stabilized in their analgesic regimen at least four weeks prior to enrollment into study. TCA, if taken, was discontinued for two weeks for wash out period. Baseline four point verbal pain intensity score was obtained and oral administration of paroxetine 20 mg was initiated. At two weeks follow-up visit, pain intensity scores, pain improvement scores judged by family, drug efficacy, tolerability and overall evaluation were assessed. The incidence of side effects were also obtained. Result: After two weeks of treatment, pain intensity scores decreased in 77.5% of patients and no patients experienced aggravation. These findings were objectively reflected in pain improvement scores judged by family members. But, the number of nonresponders was different among groups. In drug efficacy, tolerability and overall evaluation, the proportions of patients who scored as excellent or good were 75%, 80% and 80% respectively. Incidence of side effects was 27.5%, but the side effects spontaneously disappeared after discontinuation of medication. Conclusion: Paroxetine, a selective serotonin reuptake inhibitor, appears to be effective as adjuvant analgesic for the management of various neuropathic pain syndromes.

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Impact of Online Communities' Characteristic on Community Trust and Information Acceptance - Focus on Online Wedding Communities for Unmarried Females in their 20s and 30s - (온라인 커뮤니티 특성이 커뮤니티 신뢰 및 정보수용 행동에 미치는 영향 - 20~30대 미혼 여성의 온라인 웨딩 커뮤니티를 중심으로 -)

  • Lee, Eun Jin;Choo, Ho Jung;Lee, Mi Ah
    • Fashion & Textile Research Journal
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    • v.16 no.2
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    • pp.208-217
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    • 2014
  • This study focuses on analyzing a subset of consumer activities (especially social medium) in their wedding preparation. The focus of this study is on wedding online communities and understanding the impact of communities on selective behavior for information-acceptance. Data was compiled based on female consumers in their 20s and 30s who actively participate in online community forums. It included female consumers preparing for their weddings and individuals interested in weddings. A total of 211 questionnaires were collected from January $10^{th}$ to $23^{rd}$ in 2012. The online communities were identified from Naver, Yahoo, and online search portals; subsequently, they were rank-sorted based on number of members, visitors, and forum posts. We identified four different characteristic based on the findings from the analysis of on-line wedding communities. The characteristic of these communities were divided into sharing experience, functionality of the webpage, informativeness, and interactivity; consequently, use of these online communities is based on trust and significant personal relationships between the members online. Out of the four different community characteristics, sharing experience was found to have a greater impact for the selective behavior of wedding dresses and information- acceptance than the functionality of the webpage, interactivity, and informativeness. We conclude that trust in information provided by members with marriage process experience is the foremost important factor in the behavior of individual consumers wit iexplore.exe -extoff hout marriage process experience. Therefore, the impact of these online communities catering to would-be brides is based on the trust of posters and how well it is articulated.

Design of a High-Performance Match-Line Sense Amplifier for Selective Match-Line charging Technique (선택적 매치라인 충전기법에 사용되는 고성능 매치라인 감지 증폭기 설계)

  • Ji-Hoon Choi;Jeong-Beom Kim
    • The Journal of the Korea institute of electronic communication sciences
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    • v.18 no.5
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    • pp.769-776
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    • 2023
  • In this paper, we designed an MLSA(Match-line Sense Amplifier) for low-power CAM(Content Addressable Memory). By using the MLSA and precharge controller, we reduced power consumption during CAM operation by employing a selective match-line charging technique to mitigate power consumption caused by mismatch. Additionally, we further reduced power consumption due to leakage current by terminating precharge early when a mismatch occurs during the search operation. The designed circuit exhibited superior performance compared to the existing circuits, with a reduction of 6.92% and 23.30% in power consumption and propagation delay time, respectively. Moreover, it demonstrated a significant decrease of 29.92% and 52.31% in product-delay-product (PDP) and energy-delay-product (EDP). The proposed circuit was validated using SPECTRE simulation with TSMC 65nm CMOS process.

Antioxidant Activity of Cholesterol Derived from Silkworm Pupae

  • Heo, Jung-Eun;Ryu, Jae-Ha;Jeong, Hye-Kyoung;Chung, Wan-Tae;Ahn, Mi-Young
    • Natural Product Sciences
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    • v.13 no.3
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    • pp.220-224
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    • 2007
  • To search of more selective vasculogenic relaxation activity, the antioxidant activity of silkworm male pupae was determined by measuring its radical scavenging effect on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals, and anticoagulant activity of them was measured clotting time in both activated partial thromboplastin time (aPTT). Because, most of cGMP-enhancing agent such as, sildenafil, promotes thrombin-induced platelet aggregation, developed unexplained thrombic conditions including heart attack. To search more suitable and safe drug for vasculogenic relaxation, we purified silkworm pupae male extract. The ethyl acetate extract of silkworm male pupae showed strong scavenging activity in both DPPH and aPTT anticoagulant activity. The antioxidant activity potential of the individual fraction was in order of ethyl acetate > n-butanol > chloroform > n-hexane. The ethyl acetate soluble fraction exhibiting strong anti-oxidant and anticoagulant activity was further purified by repeated silica gel and Sephadex LH-20 column chromatography. Cholesterol was isolated as one of the active principles from ethyl acetate fraction, together with, minor portion, ${\beta}-sitosterol$.

Performance Analysis of Maximum-Likelihood Code Acquisition Technique for Preamble Search in CDMA Reverse Link (CDMA 역방향 링크에서의 프리앰블 탐색을 위한 최대우도 동기획득 방식의 성능 분석)

  • 박형래;강법주
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.1
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    • pp.161-174
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    • 1996
  • Addressed in this paper is performance analysis of the maximum-likelihood code acquisition technique for slotted-mode preamble search in the CDMA reverse link. The probabilities of detection, miss, and false alarm are derived analytically for a multiple $H_{1}$ cell case in a frequency-selective Rayleigh fading channel, based on the statics of the CDMA noncoherent demodulator output. the probability density function of the decision variable consisting of successive demodulator outputs is also derived by considering the fading characteristics of the received signal for both single and dual antenna cases. The performance of the code acquisition technique is evaluated numerically with an emphasis on investigating the effects of post-detection integration, fading rate, and antenna diversity on the detection performance.

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