• 대한임상검사과학회지
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• 제38권2호
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• pp.87-93
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• 2006

This study was done to know a kind and change (transition) of enzymes produceed by Streptomyces halstedii ssp. scabies SA1-27 and Streptomyces violaceusinger C1-6 which showed good lignolytic activity and a good decolorization ratio of remazol brilliant blue R(RBBR) dye. These strains were isolated from soil and identified by the author. The basal medium containg 0.2% glucose was used to measure enzyme activity, Lignin peroxidase 1 (Lip 1) was measured by the methods of Choi, and Bourbonnais and Paice. Lignin peroxidase 2 (Lip 2) was measured by the methods of Ishida et al and Ramachandra et al using 2.4-dichlorophenol(2.4 DCP), manganese peroxidase(Mnp), veratryl alcohol oxidase (VAO), and laccase. They were measured by each of the methods of Choi and Paszczynski et al, and Bourbonnais and Paice, and De Jong et al. In the results, the kind of enzymes produced by Streptomyces halstedii ssp. scabies SA1-27 were Lip 1, Lip 2, VAO, and laccase, and their activities indicated the highest value as each 4.95 nmol/mg protein, $8.45({\times}100^{-3})unit$, 10.25 nmol/mg protein, 9.20 nmol/mg protein on the sixth day of the culture and decreased gradually over time. The kind of enzymes produced by Streptomyces violaceusinger C1-6 were Lip 1, Lip 2, Mnp, VAO, and laccase, and their activities indicated the highest value as each 4.90 nmol/mg protein, $13.85({\times}100^{-3})unit$, 3.10 nmol/mg protein, 11.30 nmol/mg protein, 4.45 nmol/mg protein on the sixth day of the culture and decreased gradually over time. Consequently, the author knew the fact that there were few differences in the kind and quantity of enzymes produced by the two Streptomyces strains, but all enzyme activities indicated the highest value on the sixth day of the culture and decreased gradually over time.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2006년도 한국컴퓨터종합학술대회 논문집 Vol.33 No.1 (D)
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• pp.85-87
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• 2006

센서 네트워크에서의 네트워크 리프로그래밍은 무선 통신을 통해 센서 노드에서 수행되는 소프트웨어를 변경하는 것으로서, 이를 사용하면 센서 네트워크를 구성하는 수백 개 혹은 수천 개의 노드들의 소프트웨어를 효과적으로 변경시킬 수 있다. 현재 네트워크 리프로그래밍을 위해 XNP, MNP. MOAP, Deluge, Mate 및 Incremental 기법 등이 제안되어 왔지만 아직 만족할만한 방법은 찾아보기 힘든 실정이다. 본 논문에서는 멀티홉을 지원하는 Deluge에 Incremental 기법을 통합하여 효율적인 리프로그래밍 기법을 구현하였다. 제안된 기법은 TinyOS 1.1.14 버전에 구현되었으며, 이를 통해서 네트워크 리프로그래밍을 위해 요구되는 패킷의 수와 소요시간을 크게 단축시킬 수 있다. 또한 센서 노드에서 패킷 전송에 따른 전력소 모가 가장 큰 점을 고려할 때 본 연구에서 제안하는 방식을 사용하면 센서 노드의 전력소모량도 크게 감소시킬 수 있는 효과를 기대할 수 있다.

• Macromolecular Research
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• 제17권4호
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• pp.259-264
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• 2009

Chemical modification of magnetic nanoparticles(MNPs) with functional polymers has recently gained a great deal of attention because of the potential application of MNPs to in vivo and in vitro biotechnology. The potential use of MNPs as capturing agents and sensitive biosensors has been intensively investigated because MNPs exhibit good separation-capability and binding-specificity for biomolecules after suitable surface functionalization processes. In this work, we demonstrate an efficient method for the surface modification of MNPs, by combining surface-initiated polymerization and the subsequent conjugation of the biologically active molecules. The polymeric shells of non-biofouling poly(poly(ethylene glycol) methacrylate)(pPEGMA) were introduced onto the surface of MNPs by surface-initiated, atom transfer radical polymerization(SI-ATRP). With biotin as a model of biologically active compounds, the polymeric shells underwent successful post-functionalization via activation of the polymeric shells and bioconjugation of biotin. The resulting MNP hybrids showed a biospecific binding property for streptavidin and could be separated by magnet capture.

• 전자공학회논문지A
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• 제28A권11호
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• pp.866-873
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• 1991

In this paper the electric and magnetic field distributions in a TEM cell used for EMC testing are analyzed numerically. The fields are distorted with the increase of frequency. These distortions are due to higher order modes and resonances and cause the bandwidthe limitations in the uae of TEM cels. The upper frequency is lower modes however, are reflected at some points through the tapered ends of the cell. Higher order modes however, are reflected at some points within the tapered region where it becomes too small to support the modes, The first two TE mode(TE$_{01}$ and TE$_{10}$) cutoff frequencies and the first six TE$_mnp$ resonant ferquencies are identified in a TEM cell (1x0 6x2m,w=0.72m) from field patterns and the results are consistent with others' data. The circumferential wall currents to support resonances are shown. For the large cell it is desired to extend the usable frequency range above the cutoff frequency of the first higher order mode. This study proposes an attempt to expand the frequency bandwidth by a resonance suppression.

• 농촌계획
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• 제24권4호
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• pp.27-35
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• 2018

This study analyzed the factors influencing the choice of new farming type in order to prepare the countermeasures against structural changes of farm labor force. The analytical model was the multinomial logit model(MNL). The test for Independence and Irrelevance Alternatives(IIA) assumption in MNL shows that the IIA assumption in our data is rejected. Alternatively, we chose the multinomial probit model(MNP) that does not assume IIA. Data were obtained from 2010 census of Agriculture, Forestry and Fisheries of Statistics Korea. New farming types are succession(13.9%), return-to-farming(45.0%), part-time-farming(32.5%) and etc(8.6%). Analysis results showed that the characteristics of farms, commodity, management, and region influenced the choice of new farming type. This study is expected to help policy makers to produce support policies by new farming types in order to increase the number of new farmers and to make them easier to settle down in agriculture.

• Current Applied Physics
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• 제18권11호
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• pp.1410-1414
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• 2018

Magnetic nanoparticles (MNP) have attracted considerable interest in many fields of research and applied science due to their impressive properties. In the past, especially biomedical problems have promoted the development of MNPs. For technical applications e.g. wastewater treatment and absorption of electromagnetic waves, the existing synthesis approaches are too expensive and/or the producible quantities are too low. In this work we present a method for simple preparation of size-controlled magnetic iron oxide nanoparticles by electroerosion dispersion (EED) of carbon steel in water. We describe the synthesis method, the laboratory installation and discuss the structural, chemical and electromagnetic properties of the synthetized EED powders as well as their applicability for microwave absorption compared to other available ferrite powders.

• 공업화학
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• 제10권7호
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• pp.979-984
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• 1999

2,2-Bis(3-amino-4-hydroxyphenyl)hexafluoropropane(BAPAF)과 pyromelltic dianhydride(PMDA), 3,3',4,4'-benzophenontetracarboxylic dianhydride(BTDA), 4,4'-(hexafluoroisopropylidene)-bis(phthalic anhydride)(6FDA)을 사용하여 용해성 폴리이드를 합성하였다. 합성된 폴리이미드를 여러가지 유기용제(acetone, NMP, DMAc, DMSO, THF, DMF)를 이용하여 용해성 실험을 행한 결과 열적 이미드화한 경우에는 녹지 않고 팽윤 되었으나 화학적 이미드화한 경우에는 모든 구조가 여러 유기용제에 대해 좋은 용해성을 나타냈다. 이러한 용해도 차이는 화학적 이미드화할 경우 탈수제로 들어간 acetic anhydride에서 나온 $CH_3COO^-$가 하이드록실기와 에스테르 반응을 하여 분자사슬에 결합한데 기인한다. 합성된 폴리이미드의 유리전이온도는 열적 이미드화 경우가 더 높은 값을 나타냈으며 TGA 측정 결과 모든 구조가 $300^{\circ}C$ 이상까지 열적 안정성을 나타내었다. 합성된 폴리이미드의 결정성은 XRD를 이용하여 조사한 결과 모두 무정형으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권11호
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• pp.1642-1649
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• 2003

An experiment was conducted to evaluate the effects of phytase supplementation on the growth performance, nutrients utilization and bone mineralization in broiler chickens. Day-old broiler chicks (n=480) were equally devided into eight treatment groups and fed maize or wheat based isocaloric, isonitrogenous and isocalcium diets having two non phytate phosphorus (NPP) concentrations (0.50% and 0.30%) and two phytase levels (0 and 500 phytase units/kg diet) in a 42 days growth trial. Maize based dietary treatments were MC (NPP 0.50%, MN (NPP 0.30%), MNP (MN+500 units of phytase) and MCP (MC+500 units of phytase), whereas wheat based experimental diets were WC (NPP 0.50%), WN (NPP 0.30%), WNP (WN+500 units of phytase) and WCP (WC+500 units of phytase). The NPP levels were maintained by dicalcium phosphate. Reduction in dietary NPP depressed live weight gain and feed intake and increased feed conversion ratio (FCR). Phytase supplementation to low NPP (0.30%) diets significantly (p<0.05) improved the growth performances of broilers. The supplementation to low NPP diets allowed complete, safe and economic replacement of dietary inorganic P (dicalcium phosphate) to reduce feed cost per kg live weight gain of broilers. Reduction in dietary NPP did not affect retention of nutrients except phosphorus (P) but had a significant (p<0.05) depression in tibia ash and minerals (Ca, P) concentration in serum and tibia ash. Phytase supplementation at low NPP level was effective (p<0.05) in improving the retention of dry matter, Ca and P and Ca and P concentration in serum and tibia ash. However, the supplementation was not effective at high level of NPP (0.50%). There were no significant (p>0.05) differences in carcass quality among dietary treatments. The response of phytase was greater in low NPP and maize based diets as compared with high NPP and wheat based diets, respectively. The results show that phytase supplementation to low NPP (0.30%) diets improved the growth performance, relative retention of nutrients (N, Ca and P) and minerals (Ca, P) status of blood and bone in broiler chickens, with a better efficacy in maize based diets.

• 한국컴퓨터산업학회논문지
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• 제5권9호
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• pp.1101-1110
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• 2004

2004년도 1분기 현재 세계 이동통신 가입자는 약13억 4,800만명으로 인구대비 보급률은 아직 29%에 불과하나, 2004년 5월 현재 국내 이동 전화 가입자는 3천 6백만 명을 넘어서, 인구대비 보급률 75%를 상회하면서 우리 나라도 이동통신강국에 진입하고 있다. 무선인터넷 서비스는 1999년 5월 처음 서비스를 제공한 이후 통신사의 꾸준한 투자와 단말기의 고급화(컬러폰, 디지털 카메라폰) 및 번호이동성 (MNP) 제도도입 등으로 지속적인 증가추세로 2004년 5월 현재 무선인터넷 가입자는 총 3천 450만 명으로 이동전화 가입자 대비 95.3%의 가입률을 기록하고 있다. 이동전화 시장은 요금인하 또는 품질개선 등의 지속적인 질적 경쟁보다는 가입자의 양적 유치경쟁에 치우치고 있어 이용자들이 다양한 무선인터넷 서비스를 합리적으로 선택할 수 있도록 무선인터넷 서비스의 사전 요금정보의 제공과 무선인터넷 서비스의 요금체계 개선을 위하여 본 논문에서는 무선 인터넷의 접속 및 컨텐츠 다운로드로 DATA를 측정하고 결과를 분석하여 과금 체계의 개선방향을 제시하여 무선인터넷 서비스의 활성화에 기여하고자 한다.

• 정보처리학회논문지C
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• 제12C권4호
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• pp.597-602
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• 2005

본 논문에서는 이동통신 3사의 무선인터넷 서비스 시스템의 패킷 과금방식에 대하여 과금체계 검증시험을 실시하여 측정용 파일크기와 사업자의 과금데이터를 비교 분석하였다. 검증시험 결과에 나타난 바와 같이 이동통신사의 무선환경에 영향을 받는 망 품질에 따라서 과금데이터가 전송 오버헤드들로 인하여 차이가 발생되고 있어, 이동통신사간의 통일된 패킷의 과금적용을 위해 패킷 분석시스템을 제안하였다. 과금시스템에 패킷 분석시스템을 추가하여 보완하면, 서비스별 프로토콜 분석을 통해 패킷 데이터를 추출하고 트래픽 데이터를 분석하여 콘텐츠 유형별 분류할 수 있어 이동통신사간의 패킷별 과금적용 및 콘텐츠 가치에 기반한 차등과금이 가능하고, 사용 내역의 상세한 정보를 요구하는 고객의 욕구를 충족시킬 수 있으며, 비과금 패킷 처리에 대한 과금요건을 수용하는 둥 보다 유연하고 다양한 과금정책을 지원할 수 있다. 이는 향후 이용자들의 요금에 대한 민원들이 줄게 되어 무선인터넷 서비스의 활성화에 크게 기여할 것이다