• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 춘계학술대회
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• pp.19-19
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• 2020

The Cassava(Manihot esculenta Crantz) is a tropical root crop, originally from Amazonia, that provides the staple food of an estimated 800 million people worldwide. It belongs to the family Euphorbiaceae which also includes rubber (Hevea brasiliensis) and castor bean (Ricinus communis). Among tropical crops, rice, sugarcane, maize and cassava are the most important sources of calories for human consumption. Problems in the propagation of cassava are virus diseases and low rates of seed germination. So we tried to optimize protocols for mass production of somatic embryo amenable to large-scale vegetative propagation of Cassava. After in vitro eight-week culture of leaves of Cassava, the medium which contained the 2,4-D, BAP and IBA showed the highest callus induction rate, embryogenesis callus formation rate and somatic embryo formation in Cassava culture. In the medium with GA₃ and myo-inositol, shoots were most vigorously regenerated from somatic embryos of Cassava. Our experiments confirmed that in vitro growth and multiplication of plantlets could depend on its reaction to the different medium composition, and this micropropagation techniques could be a useful system for healthy and vigorous plant production.

• 시큐리티연구
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• 제62호
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• pp.321-346
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• 2020

이 연구는 보안경비 이용자의 고객접점서비스, 내적반응과 소비행동간 간의 관계를 구조모형을 통해 규명하는 것이 목적이다. 이 연구는 보안경비 서비스를 이용하는 구매자의 실증적인 대면이 되는 접점서비스의 중요성을 파악하고 이에 따른 소비자의 반응과 소비행동의 관계를 규명함으로서 보안경비 산업 발전에 기여할 수 있다는 점에서 의미가 있다할 것이다. 연구대상은 충청남도 천안시 및 아산시의 상가 밀집지역을 중심으로 보안경비서비스를 이용하고 있는 점포로 하고 여기서 점포 대표 및 직원 375명을 선정하여 연구를 수행하였다. 조사도구는 국내·외 선행연구를 기초로 하여 연구의 목적에 맞게 수정하여 사용하였다. 자료처리는 SPSS 25.0과 AMOS 25.0 두 가지 통계프로그램을 이용하여 빈도 분석, 탐색적 요인분석, 신뢰도 분석, 확인적 요인분석, 구조모형분석을 실시하였다. 통계적 유의 수준은 .05로 설정하여 분석하였으며, 자료 분석을 통하여 다음과 같은 결론을 얻었다. 첫째, 보안경비 이용자의 고객접점서비스는 소비행동에 정(+)의 영향을 미친다. 둘째, 보안경비 이용자의 고객접점서비스는 내적반응에 정(+)의 영향을 미친다. 셋째, 보안경비 이용자의 내적반응은 소비행동에 정(+)의 영향을 미친다. 넷째, 보안경비 이용자의 고객접점서비스와 소비행동 간의 매개효과로써 내적반응은 정(+)의 영향을 미친다.

• 기독교교육논총
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• 제66권
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• pp.113-145
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• 2021

이 연구는 기독교교육의 성찰을 위해 보드리야르(J. Baudrillard)의 중요개념인 시뮬라시옹(Simulation)과 시뮬라크르(Simulacra) 등을 중심으로 포스트 코로나 시대의 한 단면을 분석할 수 있는 드라마 「펜트하우스」의 소비이데올로기, 이미지의 욕망 및 폭력 등에 관해 검토할 것이다. 보드리야르는 시뮬라시옹 개념이 대중매체의 발전에서 생겨났다고 보고, 대중매체는 결국 실재를 사라지게 하는 '시뮬라시옹의 출현' 혹은 '시뮬라시옹의 과정'이라고 설명한다. 보드리야르는 시뮬라시옹 과정이 대중매체가 지배하는 소비사회의 다양한 영역에서 진행되고 있다는 것을 지적한다. 시뮬라시옹은 이미지에 의해 실재보다 더 실재적인 초과실재를 산출하는 과정이며, 시뮬라크르는 시뮬라시옹의 결과이다. 포스트 코로나 시대의 기독교교육은 비판이론을 통한 비판적 성찰의 준거 기준이 합의 되지 않았다는 부정적 측면으로 인해 거부하지 말고 비판이론의 긍정적 입장을 고려해야 한다. 다시 말해서 대중매체가 주도하는 지배이데올로기와 소비이데올로기의 속성을 봐야한다. 특히 광고나 드라마 영화에서 보여주는 메시지는 시뮬라크르만 남아 실제보다 더 실제 같은 허상임을 보는 관점을 지녀야 한다. 미디어는 말을 하되 상대방의 응답이 이루어질 수 없게 만드는 미디어의 권력을 의미한다. 그것의 대표적인 예표가 텔레비전이며, 연구자가 드라마 「펜트하우스」를 분석하는 이유이기도 하다. 보드리야르는 맥루한(M. McLuhan)의 "미디어가 메시지다"(The medium is the message)라는 명제는 예상치 못하게 모든 내용물과 메시지가 미디어 속으로 사라져 버린 뒤에, 미디어 자신도 증발해 버린다고 지적한다. 그러나 기독교교육은 "하나님 말씀이 메시지"(The word of God is message)임을 가르치고, 배우고, 나누고, 전수하는 것이다. 또한 그 메시지는 내파되거나 함열되는 것이 아니라 영원한 진리로 계속 살아있는 메시지이다. 위기와 불안의 포스트 코로나 시대의 기독교교육은 사회 현상과 관련하여 대중/소비자/교인 개체들을 무저항적이고 무비판적으로 만드는 소비지상주의의 소비문화에 관해 끊임없는 성찰의 장(場)을 마련하고, 일련의 '전망대'의 역할을 감당해야 할 것이다.

• Journal of Information Processing Systems
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• 제2권1호
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• pp.39-43
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• 2006

In this paper, we proposed TASL-MAC, a medium-access control (MAC) protocol for wireless sensor networks. In wireless sensor networks, sensor nodes are usually deployed in a special environment, are assigned with long-term work, and are supported by a limited battery. As such, reducing the energy consumption becomes the primary concern with regard to wireless sensor networks. At the same time, reducing the latency in multi-hop data transmission is also very important. In the existing research, sensor nodes are expected to be switched to the sleep mode in order to reduce energy consumption. However, the existing proposals tended to assign the sensors with a fixed Sleep/Listening schedule, which causes unnecessary idle listening problems and conspicuous transmission latency due to the diversity of the traffic-load in the network. TASL-MAC is designed to dynamically adjust the duty listening time based on traffic load. This protocol enables the node with a proper data transfer rate to satisfy the application's requirements. Meanwhile, it can lead to much greater power efficiency by prolonging the nodes' sleeping time when the traffic. We evaluate our implementation of TASL-MAC in NS-2. The evaluation result indicates that our proposal could explicitly reduce packet delivery latency, and that it could also significantly prolong the lifetime of the entire network when traffic is low.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권2호
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• pp.142-146
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• 2003

Three insect cell lines, Sf9, Sf21 and Tn5Bl-4, and four different kinds of serum free media (SFM), Sf 900 II, EX-CELL 420, EX-CELL 405 and Express Five, were used to compare the nutrient consumption, byproduct formation, production of recombinant protein and protease activity in suspension cultures. The Sf 900 II SFM was a ppropriate for the cell growth and protein production of the Sf9 and Sf21 cell lines. When the Tn5Bl-4 cell line was grown in the Express Five SFM, the specific growth rate was 1.6 fold higher than those of either the Sf9 or Sf21 cell lines. The glucose and glutamine consumption rates per cells, were 4 and 2.3 times higher than those of the Sf9 cell line, respectively. The overall yield coefficients of the lactate and ammoniumion were 2.8 and 1.5 times higher compared to those of the Sf9 cell line. respectively. The maximum specific ${\beta}$-galactosidase production rate was 4.5 fold that of the Sf9 cell line, a 3 times higher protease activity per cell.

• Archives of Pharmacal Research
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• 제20권5호
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• pp.471-475
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• 1997

Livers isolated from 18 hours fasted rats were subjected to N$_{2}$ hypoxia (for 45 min) followed by reoxygenation (for 45 min). The perfusion medium used was Krebs-Henseleit bicarbonate buffer (KHBB, pH 7.4). Lactate and alanine were added as gluconeogenic and ureagenic substrates and Trolox C was also added to perfusate. Oxygen consumption, lactate dehydrogenase (LDH), alanine transaminase (ALT), total glutathione, oxidized glutathione, bile flow, glucose and urea were measured. After hypoxia oxygen consumption significantly dropped but Trolox C had no influence on this decrease. ALT and LDH were significantly increased by hypoxia/reoxygenation. This increase was markedly attenuated in the presence of Trolox C. The total glutathione and oxidized glutathione efflux increased following hypoxia, which were prevented by the treatment of Trolox C. Bile flow rate decreased following hypoxia/reoxygenation but did not continue to decrease in the reoxygenation phase by Trolox C. Following hypoxia/reoxygenation glucose and urea releases decreased. Trolox C had no influence on inhibition of glucose and urea production. These results suggest that Trolox C protected the liver cells against hypoxia/reoxygenation injury, yielding further evidence for a causative role of oxidative stress in this model.

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1127-1134
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• 2009

Escherichia coli excretes acetate during aerobic growth on glycolytic carbon sources, which has been explained as an overflow metabolism when the carbon flux into the cell exceeds the capacity of central metabolic pathways. Nonacetogenic growth of E. coli on gluconeogenic carbon sources like succinate or in carbon-limited slow growth conditions is believed an evidence for the explanation. However, we found that a strain defected in the acs (acetyl Co-A synthetase) gene, the product of which is involved in scavenging acetate, accumulated acetate even in succinate medium and in carbon-limited low growth rate condition, where as its isogenic parental strain did not. The acs promoter was inducible in noncatabolite repression condition, whereas the expression of the ackA-pta operon encoding acetate kinase and phosphotransacetylase for acetate synthesis was constitutive. Results in this study suggest that E. coli excretes and scavenges acetate simultaneously in the carbon-limited low growth condition and in nonacetogenic carbon source, and the activity of the acetate consumption pathway directly affects the accumulation level of acetate in the culture broth.

• Journal of Dairy Science and Biotechnology
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• 제28권1호
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• pp.1-7
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• 2010

In 2009, the world dairy industry had the most impressive experience throughout all the experiences it had. The milk price in major regions fell to their lowest level for decades. Including Korea, the world economy is obviously slowing. The nations' export plunged due to the global economic recession, in result reduced industrial output and domestic demand. In Korea, the intake of liquid milk slightly decreased from 45 kg per capita in 2005 to 44.3 kg per capita in 2008. However, production and consumption of milk increased fast in China and India. According to 2008 statistics, total milk volume of the world trade reached 42 million tonnes and the major exporters of dairy products were EU, New Zealand, USA and Autralia. The tropical countries has traditionally consumed buffalo milk. The production of buffalo milk is increasing faster than cow milk. IDF expected that EU milk production would recover the medium term displaying a gradual growth over the milk quotas phasing-out period, while constantly remaining below the quota level.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.13-14
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• 2005

Multi-dimensional combustion analysis and experiment has been carried out to investigate the effects of the injector nozzle hole diameter and number on the NOx formation and fuel consumption in HYUNDAI HiMSEN engine. The behavior of spray and combustion phenomena in diesel engine was examined by FIRE code. Wave breakup and Zeldovich models were adopted to describe the atomization characteristics and NOx formation. Wallfilm model suggested by Mundo, et al. and auto-ignition model suggested by Theobald and Cheng were adopted to investigate the spray-wall interaction characteristics and ignition delay. The information of spray angle and spray tip penetration length was extracted from fuel spray visualization experiment and the fuel injection rate profile was extracted from fuel injection system experiment as an input and verification data for the combustion analysis. Next, the nine different nozzle configurations were simulated to evaluate the effect of injector hole diameter and number on the NOx formation and fuel consumption.

• Journal of Ginseng Research
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• 제9권1호
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• pp.86-94
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• 1985

Attempts were made if diol and triol fractions of ginseng saponin affect on glutamine transport into rat renal cortical mitochondria, swelling, phosphate dependent glutaminase activity, and consumption of oxygen. The following results were obtained. When mitochondrial preparation from rat renal cortex was incubated in medium containing 14C-glutamine and either triol or diol fractions, radioactivity was shown to increase at both 10-6% and 10-5% triol fractions of ginseng saponin, but reduce in case of diol fraction. The remarkable acceleration of the rate of swelling of renal cortical mitochondria was observed in the presence of 10-1% trios and diol fractions but no accerelation at lower concentrations. The activity of phosphate dependent glutaminase from renal cortical mitochondria was slightly activated at 10-2% of triol fraction. However, there was no effect in case of diol fraction. Oxygen consumption by mitochondria from renal cortex was remarkably increased at concentrations of 10-5% and 10-6% triol fractions, but reduced in the case of diol fractions. On the basis of these observations it was concluded that triol fraction of ginseng saponin might increase the transport of glutamine into mitochondria by accelerating the respiratory chain and supplying additional energy to mitochondria, and physiological role of triol fraction was entirely different from that of diol fraction of ginseng saponin.