• Journal of Communications and Networks
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• 제13권1호
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• pp.43-49
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• 2011

In this paper, a new medium access control (MAC) protocol entitled three-phase multiple access with continual contention resolution (TPMA-CCR) is proposed for wireless multi-hop ad hoc networks. This work is motivated by the previously known three-phase multiple access (TPMA) scheme of Hou and Tsai [2] which is the suitable MAC protocol for clustering multi-hop ad hoc networks owing to its beneficial attributes such as easy collision detectible, anonymous acknowledgment (ACK), and simple signaling format for the broadcast-natured networks. The new TPMA-CCR is designed to let all contending nodes participate in contentions for a medium access more aggressively than the original TPMA and with continual resolving procedures as well. Through the systematical performance analysis of the suggested protocol, it is also shown that the maximum throughput of the new protocol is not only superior to the original TPMA, but also improves on the conventional slotted carrier sense multiple access (CSMA) under certain circumstances. Thus, in terms of performance, TPMA-CCR can provide an attractive alternative to other contention-based MAC protocols for multi-hop ad hoc networks.

• 대한의생명과학회지
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• 제17권1호
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• pp.89-93
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• 2011

Asthma is an inflammatory airway disease and is characterized by the releases of inflammatory mediators including chemokines. They are mainly associated with the recruitment, activation and dysregulation of specific inflammatory cells, especially neutrophils in neutrophilic asthma. CC chemokines bind to CC chemokine receptors (CCRs) in the surface of their target cells. The aims of this study are to examine the CCR expression in neutrophils of bronchoalveolar lavage fluid (BALF) of asthmatic patients and to determine the alternation of migration and apoptosis of neutrophils by the BALF. We demonstrate that CCR3 strongly expresses in BALF neutrophils of asthmatic patients as compared to other CCRs and increases during apoptosis of the BALF neutrophils. The migration of asthmatic blood neutrophils increases in response to asthmatic BALF as compared to BALF of normal volunteer. In addition, asthmatic BALF includes the higher levels of IL-8 protein than normal BALF and it has no effect on apoptosis of asthmatic blood neutrophils. Taken together, our results indicate that CCR3 expression may be associated with unknown function of asthmatic BALF neutrophils and BALF may be involved in the recruitment of neutrophils into the airway, but not in the neutrophils apoptosis.

• 디지털융복합연구
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• 제10권9호
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• pp.159-164
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• 2012

디스플레이 산업은 한국경제에서 중요한 역할을 하고 있음에도 불구하고, 디스플레이 기업의 효율성을 분석한 연구는 수행되지 않았다. 본 논문의 목적은 DEA 모형을 이용하여 국내 상장 디스플레이 기업의 효율성을 분석하고 측정하는 것으로 DEA의 CCR 모형과 BCC 모형을 이용하여 국내 상장 디스플레이 기업의 효율성을 평가하고 규모의 효율성도 평가한다. 또한 비효율 그룹으로 분류된 기업이 효율성 그룹으로 이동하기 위해 효율성 그룹을 벤치마킹을 통하여 개선해야할 효율성 수치도 제공한다. 본 연구에서는 2010년말 기준 7개의 코스피 상장 기업과 37개의 코스닥 상장기업을 포함한 44개의 상장 기업을 분석하였다. 분석 결과 CCR 모형에서 효율성이 1인 기업은 6개였으며 BCC모형에서는 14개였다. 추가적으로 6개 기업의 규모의 효율성을 가지고 있는 것으로 분석되었다. 궁극적으로 효율성 분석은 비효율 그룹이 기업이 벤치마킹 기업을 찾아 효율성을 개선하기 위한 유용한 정보를 제공할 수 있다.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.131-137
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• 2001

Previous work has identified that only the catabolite responsive element A (creA; previously called cre-2) out of two potential cre sequences (cre-1: nucleotide +160 to +173 and cre-2: +173 to +186), recognized within the coding region of the xylanaseA gene (xynA) of Bacillus stearothermophilus No.236, was actually, was actually involved in the carbon catabolite repression(CCR) of xynA expression in B. subtilis. However, the level of CCR of xynA expression in the original B.stearothermophilus No.236 strain (70-fold repression). Therefore, to search for an additional cre element in the promoter region, the upstream region of the xynA gene was subcloned by chromosome walking, and as a result, another potential cre element (nucleotide -124∼-137; designated creB) was recognized in this region. The cre-like sequence revealed a high homology to the cre consensus sequence. The xylanase activity of B. subtilis MW15 bearing pWPBR14 (containing creA and creB) cultured in a medium containing xylose as the sole carbon source was about 7.7 times higher than that observed for the same culture containing glucose. B. subtilis MW15 bearing pWPBR23 (containing only creA) produced an activity about 2.4 times higher. This pattern of CCR was confirmed using derivatives of xynA::aprA fusion plasmids. Furthermore, a measurement of the amounts of the xynA transcript showed a similar pattern as that for the production of xylanase. In addition, the synthesis of xylanase in B. subtilis QB7115 [a catabolite control protein A (ccpA) mutant strain] carrying pWPBR14 was almost completely relieved from glucose repression. Together, these results lead to a conclusion that the CCR of the expression of the xynA gene is mediated by CcpA binding at creA and creB sites in B. subtilis.

• Journal of Pharmaceutical Investigation
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• 제7권1_4호
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• pp.38-50
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• 1977

A study on the mechanism of biliary and urinary excretion of chloramphenicol has been performed in the dog. 1) Chloramphenicol administered intravenously to dogs with ligated renal pedicle, readily appeared in bile greater than in plasma. 6.9% of a 50mg /kg i. v. dose of chloramphenicol were excreted into bile within 100 minutes. During the same periods of above experiment, the bile/plasma concentration ratios(B/P ratios) were 46 to 87. 2) Chloramphenicol injected into the vein of dog was rapidly excreted into urine. 18% of the administered dose were excreted into urine within 70 minutes. In the same periods of this experiment, Ccm/Ccr ratios were greater than 1.0 in most cases. 3) In experiment of simultaneous measurement of biliary and urinary excretion of chloramphenicol, Ccm/Ccr ratios were less than 1.0 and B/P ratios were 50 to 52. 4) In experiment measured simultaneously biliary and urinary excretion both Ccm/Ccr and $C^Hcm$(hepatic clearance) were significantly declined by probenecid, but not affected by 2,4-DNP and aminophylline although 2,4-DNP increased only bile flow and aminophylline both bile and urine volume. 5) Ccm/Ccr and $C^Hcm$ were increased in proportion to increment of plasma concentration ranging from 3.3 to 30 mg% of chloramphenicol. But when plasma concentration were increased to 70mg %, Ccm/Ccr were not increased and $C_Hcm$ were reduced about 30% in comparison with values obtajned at 30mg% of chloramphenicol. 6) Free/Bound(free to bouid from) ratios ranging from 1.0 to 90.0mg% of chloramphenicol were 76.2+3.72% $(mean{\pm}S.E.)$ Above results suggest that chloramphenicol is excreted into bile by a process of active trasport, that excretion of chloramphenicol into urine was made up with dual process, reabsorption and secretion, and that renal secretion was attained by active trasport process although renal reabsorption process could not understand.

• The Korean Journal of Pain
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• 제21권3호
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• pp.187-196
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• 2008

Background: Upregulation of one type of the pro-inflammatory chemokine (CCL2) and its receptor (CCR2) following peripheral nerve injury contributes to the induction of neuropathic pain. Here, we examined whether another type of chemokine (CCL3) is involved in neuropathic pain. Methods: We measured changes in mechanical and thermal sensitivity in the hind paws of naïve rats or rats with an L5 spinal nerve ligation (SNL) after intra-plantar injection of CCL3 or met-RANTES, an antagonist of the CCL3 receptor, CCR1. We also measured CCL3 levels in the sciatic nerve and the hind paw skin as well as CCR1 expression in dorsal root ganglion (DRG) cells from the lumbar spinal segments. Results: Intra-plantar injection of CCL3 into the hind paw of naive rats mimicked L5 SNL-produced hyperalgesia. Intra-plantar injection of met-RANTES into the hind paw of rats with L5 SNL attenuated hyperalgesia. L5 SNL increased CCL3 levels in the sciatic nerve and the hind paw skin on the affected side. The number of CCR1-positive DRG cells in the lumbar segments was not changed following L5 SNL. Conclusions: Partial peripheral nerve injury increases local CCL3 levels along the degenerating axons during Wallerian degeneration. This CCL3 binds to its receptor, CCR1, located on adjacent uninjured afferents, presumably nociceptors, to induce hyperalgesia in the neuropathic pain state.

• 한국항만경제학회지
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• 제29권2호
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• pp.159-171
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• 2013

본 연구는 DEA기법을 이용하여 물류시설을 공항터미널, 물류단지, 컨테이너터미널, 화물자동차터미널로 나누어 상대적 효율성을 분석하고 물류시설의 개발 및 운영 활성화를 위한 정책적 방안을 제시하는 것을 목적으로 하였다. 분석결과 첫째, 공항터미널의 경우 CCR기준으로 대구국제공항터미널이 가장 효율적이며, 인천국제공항 미군사우편시설이 가장 비효율적인 것으로 나타났다. 인천, 충북, 대전, 부산은 규모의 비효율이 크며, 전남은 운영상의 비효율이 큼을 나타내고 있다. 둘째, 물류단지의 경우 CCR기준으로 군포 복합물류터미널이 가장 효율적이며, 인천국제공항 공항물류단지가 가장 비효율적인 것으로 나타났다. 경기와 경북은 각각 현재 투입물보다 3.5%와 44.3% 증가시켜도 효율성을 유지할 수 있음을 보여주고 있다. 셋째, 항만터미널의 경우 CCR기준으로 한진해운부산신항터미널이 가장 효율적이며, 대한통운부산컨테이너터미널이 가장 비효율적인 것으로 나타났다. 넷째, 화물자동차터미널의 경우 CCR기준으로 울산화물자동차터미널이 가장 효율적이며, 풍암화물자동차터미널이 가장 비효율적인 것으로 나타났다. 서울과 울산은 각각 현재 투입물보다 26.3%와 14.0% 증가시켜도 효율성을 유지할 수 있음을 보여주고 있다. 결론적으로 물류단지의 효율성이 가장 낮고 화물자동차터미널의 효율성이 가장 큼을 알 수 있으며, 규모의 비효율성보다는 운영상의 비효율성이 더 크게 나타났다.

• 한국항만경제학회지
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• 제33권4호
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• pp.135-148
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• 2017

본 연구는 다음과 같은 문제를 제기한다. 체선이 항만의 운영 효율성에 어느 정도 영향을 미치는가? 이 연구 문제에 대한 답하기 위해 본 연구에서는 SBM-DEA 모형을 이용하여 체선을 고려한 항만의 효율성을 분석하고 DEA-CCR BCC 모형의 연구 결과와 비교하였다. 먼저 DEA-CCR BCC 분석 결과, 부산(2011), 울산(2011)이 효율적인 DMU로 나타났으며 DEA-BCC 모형 분석 결과, 부산(2011), 울산(2011), 울산(2012), 부산(2012), 여수 광양(2012)이 효율적인 DMU로 나타났다. 체선을 고려한 SBM-DEA 모형 분석 결과, 울산(2012), 부산(2011), 부산(2012), 인천(2011), 울산(2011)이 효율적인 DMU로 나타났다. DEA-CCR BCC 결과와 SBM-DEA 결과 간 불일치를 보여 체선이 항만의 운영 효율성에 미치는 영향이 크지 않은 것으로 나타났으며 체선선박척수의 잔여물을 제거한다면 인천항은 3년간 총 11.9억 원, 여수 광양항은 3년 간 총 65.52억 원의 비용 보존이 가능한 것으로 나타났다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권7호
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• pp.3305-3311
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• 2012

Background: The present study aimed to find the prognostic implications of two polymorphisms in TP53 (p.R72P, PIN3 Ins16bp) and one in CCR5 ($CCR5{\Delta}32$) in sporadic breast cancer patients. Methods: DNA samples of 80 breast cancer patients and 80 age and gender matched unrelated healthy control individuals from Punjab, North West India were analyzed. Results: For p.R72P, the genotype frequency was 13.8% (RR), 58.8% (RP), 27.5% (PP) in patients and 33.9% (RR), 40.0% (RP), 26.5% (PP) in controls. For PIN3 Ins16bp, the genotype frequencies were 53.75% (A1A1), 37.5% (A1A2), 8.75% (A2A2) in patients and 66.3% (A1A1), 31.3% (A1A2), 2.5% (A2A2) in controls. Only 4 (5%) breast cancer patients were heterozygous for $CCR5{\Delta}32$ deletion. Common RR-A1A1-WT/WT genotype was lower while RP-A1A2-WT/WT genotype was higher in patients as compared to controls. RP-A1A1-WT/WT genotype was significantly higher in patients as compared to control individuals (p = 0.008). Conclusion: Though a clear association of any particular genotype with sporadic breast cancer or stage was not apparent, the results of present study were suggestive that sporadic breast cancer patients with RR-A1A1-WT/WT genotype might have a better response to chemotherapy, thus improving their chances of survival.

• 한국콘텐츠학회논문지
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• 제20권2호
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• pp.27-35
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• 2020

국내 반도체 산업은 수출 품목 1위이면 기술력 또한 경쟁국에 비해 높은 수준이다. 하지만 경쟁국들과의 기술 격차가 점점 줄어들고 있으며 강대국과의 무역마찰 등으로 인해 반도체 산업이 어려움에 직면해 있다. 따라서 이러한 상황에서 이를 극복하기 위해서는 반도체 기업들의 운영상 비효율성을 재정비하여 효율적인 생산 활동을 유도할 필요성이 있다. 이에 본 논문에서는 DEA 기업을 통해 반도체 산업의 경영 효율성을 분석하며 비효율적인 기업의 투사 값을 제시하며 벤치마킹의 대상이 될 수 있는 기업들의 참조 집합을 확인하고자 한다. 이를 위해 총 20개 고성장 전기·전자 기업들의 CCO와 BCC모형의 효율성과 규모 수익성(RTS)을 분석하였다. 분석 결과 BCC 효율성이 1인 기업은 총 13개, CCR 효율성이 1인 기업은 총 6개 기업으로 나타났다. 그리고 BCC, CCR 효율성이 모두 1인 기업은 총 6개 기업이었다. 또한 기업의 규모 수익성은 IRS가 10개 기업, CRS가 9개 기업 그리고 DRS가 11개 기업으로 분석되었으며 참조 빈도 분석에서는 BCC 모형에서는 11개 기업과 CCR 모형을 통해 6개 기업을 벤치마킹이 할 수 있는 기업으로 제시하였다. 이러한 결과는 반도체 기업들에게 비효율적인 운영환경을 개선할 수 있는 유용한 정보가 될 것이다.