• Tunnel and Underground Space
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• v.9 no.4
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• pp.315-327
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• 1999

Rock fracture mechanics has been widely applied to blasting, hydraulic fracturing, rock slope and many other practical problems in rock engineering. But a measuring method for the fracture toughness of rock, one of the mort important parameters in fracture mechanics as an intrinsic property of rock, has not been yet well established. To obtain mode I rock fracture toughness, the more favorable disc-typed specimens such as CCNBD, SCB, chevron-notched SCB and BDT were used in this study. Rock fracture toughness under mixed-mode and mode II conditions was measured by using the STCA applied to the CCNBD specimen. Size effects such as specimen thickness, diameter and notch length on fracture toughness were investigated. From the mixed-mode results, fracture envelops were obtained by applying various regression curves. The mixed-mode results were also compared with three mixed-mode failure criteria. In each fracture toughness test, acoustic emission was measured to get the data for determining the load levels of different crack propagation patterns.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.280-283
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• 2007

The first grid-connected, building-integrated transparent amorphous silicon photovoltaic installation has been operated since October 2004 in Yongin, Korea. The 2.2kWp transparent PV system was applied to the facade of entrance hall in newly constructed KOLON E&C R&D building. The PV module is a nominal 0.98m ${\times}$ 0.95m, 10% transparent, laminated, amorphous(a-Si) thin-film device rated at 44 Wp per module. To demonstrate the architectural features of thin film PV technologies for daylighting application, transparent PV modules are attached to the building envelope with the form of single glazed window and special point glazing(SPG) frames. Besides power generation, the 10% transmittance of a-Si PV module provides very smooth natural daylight to the entrance hall without any special shading devices for whole year. The installation is fully instrumented and is continuously monitored in order to allow the performance assessment of amorphous silicon PV operating at the prevailing conditions. This paper presents measured power performance data from the first 12 months of operation. For the first year, annual average system specific yield was just 486.4kWh/kWp/year which is almost half of typical amorphous silicon PV output under the best angle and orientation. It should be caused by building orientation and self-shading of adjacent mass. Besides annual power output, various statistical analysis was performed to identify the characteristics of transparent thin film PV system.

• The Journal of Korean Society of Virology
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• v.28 no.4
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• pp.383-391
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• 1998

A murine monoclonal antibody (mAb) specific for the envelope glycoprotein gp120 of human immunodeficiency virus type-I (HIV -1) was chemically coupled to pokeweed antiviral protein (PAP) from Phytolacca americana. The immunotoxin was purified by FPLC using S200 colum. The purified immunotoxin efficiently bound to HIV-infected T cells as evidenced by fluorescenceactivated cell sorter analysis. The immunotoxin selectively killed human T lymphoid lines infected with $HIV-1_{IIIB}$ at less than 250 pM of the immunotoxin cells, while PAP or mAb alone did not have any significant effect on infected cells. The uninfected control T cell lines were not affected. Human cells infected with HIV-2 or other HIV-1 strains were not killed, suggesting that the killing depends completely on the antibody used for coupling. These in vitro results suggest that the PAP-mAb conjugate may be used to selectively remove cells expressing viral antigens from individuals infected with HIV.

• Journal of Korea Water Resources Association
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• v.30 no.3
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• pp.225-233
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• 1997

The nonlinear effects on the statistical properties of wave groups in terms of the average nomber of waves in a group and the mean number of waves in a high run is studied in this paper utilizing the complex envelope and total phase function, random variable transformation technique and perturbation method. It tures out that the phase distribution is modified significantly by nonlinearities and it show systematic excess of values near the mean phase and the corresponding symmetrical deficiency on both sides away from the mean. for the case of threshold crossing rate, it turns out that threshold crossing rate reaches its maxima just below the mean water level rather than zero and considerable amount of probability mass is shifted toward the larger values of water surface elevation as nonlinearity is getting profound. Furthermore, the mean waves in a high run associated with nonlinear wave are shown to have larger values than the linear counterpart. Similar trend can also be found in the average number of waves in a group.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.444-444
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• 2013

변형 다중양자우물은 전자 소자와 광전자 소자에 응용할 수 있는 가능성 때문에 연구가 많이 진행되고 있다. 합성 물질들의 초격자를 연속적으로 증착, 성장하는 디지털 합금은 다중양자우물을 활용한 광전자 소자에서 응용가치가 상당히 높다. 현재 디지털 합금을 이용한 다중양자우물의 성장과 관련한 연구가 활발히 진행되고 있고, 특히 InzGaxAl1-z-xP/InAlP 다중양자우물은 광전자 소자로서의 응용가치가 부각되고 있다. 그러나 InzGaxAl1-z-xP/InAlP 다중양자우물의 성장 및 광학적 성질에 대한 연구는 많이 진행되었으나, InzGaxAl1-z-xP/InAlP 다중양자우물에서의 변형효과를 고려한 전자적 성질에 대한 연구는 미흡하다. InzGaxAl1-z-xP/InAlP 다중양자우물에 대한 전자적 성질의 연구는 광소자의 성능 향상을 위해 매우 필요하다. 본 연구에서는 디지털 합금 성장 방법으로 형성한 InzGaxAl1-z-xP/InAlP 다중양자우물의 부띠 사이 천이와 전자 분포를 고찰하였다. 온도에 따른 광루미네센스의 측정을 통해 InzGaxAl1-z-xP/InAlP 다중양자우물에서 나타나는 부띠 사이의 천이를 관찰하였다. 가변 메시 유한 차분법을 이용한 이산적 모델을 통해 변형효과가 다중양자우물 구조에서 부띠에 주는 영향을 조사하였다. 격자의 불일치로 인한 변형 효과와 8-band envelope function approximation을 고려한 슈뢰딩거 방정식을 사용하여 InzGaxAl1-z-xP/InAlP 다중양자우물에서의 전자 부띠 에너지와 에너지 파동 함수를 계산하였다. 계산한 부띠 사이 천이 에너지와 광루미네센스 측정에서 보인 엑시톤 천이 에너지를 비교하였을 때, 작은 차이 값이 나타났다. 증착과정에서의 이종접합사이에서 발생하는 불확실성을 고려한다면 이 차이 값은 오차범위 안에 포함되며, 계산 값과 실험 값이 잘 일치하는 것으로 볼 수 있다.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.1057-1062
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• 2004

The entomopathogenic bacterium Bacillus thuringiensis is the most widely used biopesticide. Insecticidal proteins, coded by genes located in plasmids, form typical parasporal, crystalline inclusions during sporulation. We isolated a Bacillus thuringiensis strain having insecticidal activity against larvae of the house fly (M. domestica) from the soils at a pig farm in Korea, and named it Bacillus thuringiensis SM. The culture filtrate from Bacillus thuringiensis SM showed strong lethality (83.3%) against M. domestica larvae. The parasporal crystal is enclosed within the spores' outermost envelope, as determined by transmission electron microscopy, and exhibited a bipyramidal form. The crystal proteins of strain SM consisted of five proteins with molecular weights of approximately ~130, ~80, ~68, ~42, and ~27 kDa on a 10% SDS-PAGE (major band, a size characteristic of Cry protein). Examination of antibiotic resistance revealed that the strain SM showed multiple resistant. The strain SM had at least three different plasmids with sizes of 6.6, 9.3, and 54 kb. Polymerase chain reactions (PCRs) revealed the presence of cry1, cry4A2, and cry11A1 genes in the strain SM. The cry1 gene profile of the strain SM appeared in the three respective products of 487 bp [cry1A(c)], 414 bp [cry1D], and 238 bp [cry1A(b)]. However, the strain SM has not shown the cry4A2 md cry11A1 genes. In in vivo toxicity assays, the strain SM showed high toxicity on fly larvae (M. domestic) [with $LC_{50}$ of 4.2 mg/ml, $LC_{90}$ of 8.2 mg/ml].

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.45-51
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• 2008

This paper presents theoretical and experimental analysis on the characteristics of the power spectrum of electormagnetic waves radiating from the spark plug and their cables of a distributorless ignition system. The theoretical study was conducted applying the microwave transmission line theory and the antenna theory. The experimental works were carried out to measure the standing wave ratio(SWR) and the radiation power spectrum of this system. As a result, it has been found that a spark plug and its cable is working as a monopole antenna radiating elelctromagnetic waves. Because of its similar structure to a monopole antenna, the envelope of radiation power spectrum distribution has a bell shape which can be obtained from a monopole antenna operating as a series resonant circuit. The frequency characteristics from the SWR measurements show a similar frequency characteristics of power spectrum of the system studied. Also, it has been found that the density of the power spectrum of the system fitting a long time used spark plug is higher than that of fitting a new spark plug.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.49-49
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• 2003

본 연구에서는 vesicular stomatitis virus G glycoprotein (VSV-G)를 envelope로 가지는 pantropic retrovirus vector system을 이용하여 재조합 human FSH 유전자가 전이된 형질전환 닭을 생산하고자 하였다. Human FSH $\alpha$ 및 $\beta$ 유전자와 CTP linker는 human pituitary gland cDNA library에서 RT-PCR 방법을 이용하여 cloning하였으며, 각각의 fragment는 FSH$\beta$-CTP-FSH$\alpha$ 순서의 단일사슬로 연결하였다. 연결된 FSH$\beta$-CTP-FSH$\alpha$는 retroviral vector 내의 $\beta$-actin promoter의 조절 하에 도입한 후, PT67 packaging cell line에 transfection하여 virus를 생산하였으며 생산된 virus는 pantropic한 virus producing cell인 GP293에 infection하여 FSH 유전자가 도입된 virus를 생산하였다. FSH 유전자의 발현을 in vitro에서 확인하기 위하여 CHO (chinese hamster ovary) 세포에 virus를 감염시킨 후, 세포의 배양액을 취하여 electrochemilumine-scence immunoassay 방법으로 정량하였다. In vitro에서 전이 후 발현이 확인된 FSH 외래유전자의 retroviral vector virus를 초원심분리로 고농축하여 stageX의 계란의 배반엽 층에 주입하였으며, 그 결과 18%의 부화율과 91%의 부화한 닭의 유전자 전이율을 확인할 수 있었다. 전이된 유전자의 확인은 FSH$\beta$와 Neo 유전자에 대한 primer를 이용한 RT-PCR의 방법을 이용하였다. In vitro에서와는 달리 in vivo에서는 FSH 유전자의 전이는 확인되었으나 발현을 확인하지는 못하였는데, 이는 적은 수의 실험군이 형질전환율에 비해 상대적이지 못하였거나, 외래 유전자인 FSH의 발현에 의한 생리적인 부작용이 유발되어 해당개체가 부화되지 못한 것으로 추정된다. 본 문제점을 해결하기 위하여 실험군의 수를 늘리고 외래 유전자에 대한 controllable expression system이 보완될 필요성이 요구되며, 이러한 점이 해결된다면 높은 유전자 전이율에 기인하여 retrovirus를 이용한 형질전환 방법은 형질전환 가금의 생산에 있어서 매우 효율적이고 주목할 만한 방법으로 사료된다.

• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.490-497
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• 2004

Although the E. coli heat-labile enterotoxin B subunit (LTB) is known to be a potent mucosal adjuvant towards co-administrated unrelated antigens and immunoregulator in T-helper 1-type-mediated autoimmune diseases, a more efficient and useful LTB is still required for prospective vaccine adjuvants. To determine whether a novel chimeric LTB subunit would produce an enhanced mucosal adjuvant activity and immune response, a number of LTB subunits were genetically fused with chimeric proteins using the epitope genes of the envelope glycoprotein E2 (gp51-54) from the classical swine fever virus (CSFV). It was found that the total serum immunoglobulin (Ig) levels of BALB/c mice orally immunized with chimeric proteins containing an N-terminal linked LTB subunit (LE1, LE2, and LE3) were higher than those of mice immunized with LTB, E2 epitope, and chimeric proteins that contained a C-terminal linked LTB subunit. In particular, immunization with LE1 markedly increased both the total serum Ig and fecal IgA level compared to immunization with LTB or the E2 epitope. Accordingly, the current results demonstrated that the LTB subunit in a chimeric protein exhibited a strong mucosal adjuvant effect as a carrier molecule, while the chimeric protein containing the LTB subunit stimulated the mucosal immune system by mediating the induction of antigen-specific serum Ig and mucosal IgA. Consequently, an LE1-mediated mucosal response may contribute to the development of effective antidiarrhea vaccine adjuvants.

• Journal of Microbiology and Biotechnology
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• v.17 no.3
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• pp.511-515
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• 2007

White-spot syndrome virus (WSSV) is a devastating, infectious virus affecting shrimp. Although sensitive techniques involving PCR have been developed to assist farmers in screening shrimp (brood stock) for WSSV prior to stocking ponds, such practices have not yet been applied in Korea. Despite the rationality of implementing screening, there has been some doubt as to whether the stocking of WSSV-PCR-negative fly epidemiologically decreases white-spot disease outbreaks. Here, we report a retrospective analysis of data from shrimp farms in the western coast of Korea where WSSV-PCR-negative brood stocks were used to stock rearing ponds. A total of 366 shrimp from Heuksan Island were sampled for WSSV with PCR. Of the tested shrimp, 7.2% (28 brood stocks) were identified as WSSV positive; only WSSV-PCR-negative shrimp were used for brood stocks. Total unit production (final shrimp production/ the area of the ponds) was higher, at 1.96, in ponds where WSSV-PCR-negative shrimp were used, as compared with 1.02 in other ponds in Korea in 2004. This retrospective analysis of WSSV in Korea may be useful to the shrimp aquaculture industry, suggesting a testable hypothesis that may contribute to the eventual control of WSSV outbreaks.