• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.791-796
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• 2007

최근 건설 산업 에서는 복합화, 대형화된 건축물이 주류를 이루고 있다. 이러한 건축물들은 불특정 다수인이 이용하기 때문에 형재난의 가능성을 많이 가지고 있다. 그리고 건축물의 복잡한 공간 구조로 인해 재난 시 인적${\cdot}$물적 피해가 대규모로 발생할 것으로 예상된다. 그러나 현재 대부분 지어진 건축물의 피난 설계는 정해진 법규 및 관련규정에만 이루어지는 사양규정의 체계로 되어 있다. 사양규정의 피난 설계는 안전환 피난 유도를 효과적으로 수향하지 못할 것이며 만약 실제 화재가 발생한다면 예상 밖의 엄청난 재난을 불러올 수 있따. 따라서 본 논문에서는 유동 인구가 많고 공간구조가 복잡한 다중이용시설물을 대표할 수 있는 코엑스 몰을 대상으로 현재 운영하고 있는 방재 설비 및 시스템과 상황별 대응체제 피난 유도를 조사를 한다. 이 분석을 통해 문제점과 재실자들의 피난 유도를 효과적으로 할 수 있는 개선방안을 제시하고자 한다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.362-362
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• 2010

Today, vast attention has been paid to periodic arrays of nanostructures due to their potential for applications such as memory with huge storage density. Such application requires large-scale fabrication of well ordered nano-sized structures. One of the most widely used methods for the ordered nanostructures is lithography. This top-down process, however, has the limit to reduce size. Here the promising alternative is the self-organization of ordered nano-sized structures such as large scale 2d carbon-induced reconstructions on W(110). In the present study, we report on the first well-resolved atomic resolution STM studies of the well-known R($15{\times}3$) and R($15{\times}12$) carbon induced reconstruction of the W(110). From the atomic image of R($15{\times}3$) for different values of tunneling gap resistance, we can tell there are no missing atoms in unit cells of R($15{\times}3$) and some atomic displacements are substantial from the clean W(110), even though not all the imaged position of atoms correspond to tungsten, but may include those of carbon. We are considering two cases; First case is related to lattice deformation, or top layer of W(110) is deformed in the process of relief of strain caused by random inserting of carbon atoms possibly in the interstitial position. In the second case, R($15{\times}3$) unit cell results from a coincidence lattice between clean W(110) substrate and tungsten carbide overlayer which has rectangular atomic arrangement and giving R($15{\times}3$) coincidence lattice. beta-W2C showing rectangular unit cell should be a candidate. Further, we report on new reconstructions. Unlike the well-known R($15{\times}12$) consisting of two parts, two inner structures between two "Backbone" structures. The new reconstruction, which we found for the first time, contains more parts between the "Backbone"s. Sometimes we can observe the reconstruction consists of only inner parts without "Backbone" parts. Thus, the observed reconstruction can be built by constructing of two types of "Lego"-like block. Moreover, the rectangle shape of "Backbone" transform to parallelogram-like shape over time, the so-called wavy-R($15{\times}12$). Adsorption of hydrogen can be the reason for this transformation.

• Journal of Korean Neurosurgical Society
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• 제30권7호
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• pp.861-869
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• 2001

Objective : In this study, we investigated the relationship between the histologic grading of meningiomas and proliferative potentials determined by the Ki-67, proliferating cell nuclear antigen(PCNA) and flow cytometry (FCM) with the aim of determining whether these potentials can be used as a parameter to the proliferative activity, in particular of atypical and malignant meningiomas. Methods : This study consisted of 47 meningiomas(6 malignant, 14 atypical, and random sampled 27 benign meningiomas). By immunohistochemical staining of Ki-67 and PCNA on formalin-fixed, paraffin-embedded sections, the anti-human rabbit polyclonal antibody against Ki-67 antigen and anti-PCNA monoclonal antibody(PC10) scores were counted. FCM was also performed on paraffin-embedded tissue using a selective staining technique for DNA. DNA ploidy, S-phase fraction, and proliferative index(PI)) were determined. Results : The results are summarized as follows ; 1) Proliferation rates as assessed by Ki-67 and PCNA closely correlated with the degree of anaplastic histologic features. 2) Proliferative potentials determined by FCM(S-phase fraction and PI) were not able to distinguish between benign and atypical/malignant meningiomas. 3) DNA ploidy was not a useful indicator of histologic grade in these tumors. 4) Proliferative potentials such as Ki-67 staining index(SI) and PCNA SI did not correlate with the ploidy pattern. 5) There was a linear correlation between Ki-67 SI and PCNA SI, but we could not find a correlation between Ki-67 SI and S-phase fraction or PI. Our results also did not show a statistically signficant correlation between PCNA SI and S-phse fraction or PI. Conclusions : We conclude that evaluation of the proliferative potentials with Ki-67 and PCNA is important as an additional factor for the prediction of malignancy in meningiomas. A dual study of Ki-67 and PCNA SIs on the same tissue might improve the accuracy with which the proliferative potential of a tumor can be predicted. We demonstrated that FCM in meningiomas is not valuable in predicting the behavior of these neoplasms, but we did observe a trend toward more malignancy with higher percent S-phase fraction and higher PI. Analysis of the S-phase fraction and PI might therefore be a useful tool to discriminate among histologic grades of meningiomas.

• 대한토목학회논문집
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• 제30권3C호
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• pp.141-148
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• 2010

지반내 존재하는 자연전위, 돌발성 전기잡음, 60Hz 전기잡음 등은 전기비저항 시험에 있어서 신뢰성을 저하하는 요인 중의 하나이다. 특히 최근 개발된 저주파 교류를 사용하는 PDC-R(Pseudo DC Resistivity) 시험의 자료해석에 있어서도 해석의 신뢰성을 저하시키는 요인이 되고 있다. 즉 직류기반 전기비저항 시험, 교류기반 전기비저항 시험 모두에 있어서 정도의 차이가 있을 뿐 전기잡음은 전기비저항 기법의 신뢰도에 여전히 영향을 주고 있다. 본 연구에서는 PDC-R 기법의 자료해석에 있어서 전기잡음의 영향을 최소화하여 기법의 신뢰성을 제고할 수 있는 방안을 제시하였다. 또한 이를 구현하는 자동화 알고리듬을 이용하여 PDC-R 기법의 적용성도 개선하도록 하였다. 본 연구에서 제안하는 PDC-R 시험데이터의 자동화 해석기법은 두 단계로 구성되어 있는데, 그 첫 번째는 다중필터링을 사용하여 입력전류와 동일한 주파수 성분을 추출하는 것이고, 두 번째 단계는 추출된 자료 중에서 안정적 거동의 신호성분만 분류해 내는 작업을 수행하는 것이다. 이러한 자동화 기법은 자연전위, 돌발성 잡음, 60Hz 전기잡음 등을 포함한 가상의 조화함수를 이용하여 그 정확성과 안정성을 확인하였다. 또한 현장적용을 통하여 제안된 기법의 적용성 및 정확성도 확인할 수 있었다.

• Animal Bioscience
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• 제36권11호
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• pp.1666-1684
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• 2023

Objective: Our objective was to examine the relationships of supplemental rumen-protected lysine (RPL) or lysine + methionine (RPLM) on lactational performance, plasma amino acids (AA) concentration, and nitrogen use efficiency of lactating dairy cows by using a meta-analysis approach. Methods: A total of 56 articles comprising 77 experiments with either RPL or RPLM supplementation were selected and analyzed using a mixed model methodology by considering the treatments and other potential covariates as fixed effects and different experiments as random effects. Results: In early lactating cows, milk yield was linearly increased by RPL (β₁ = 0.013; p<0.001) and RPLM (β₁ = 0.014; p<0.028) but 3.5% fat-corrected milk (FCM) and energy-corrected milk (ECM) (kg/d) was increased by only RPL. RPL and RPLM did not affect dry matter intake (DMI) but positively increased (p<0.05) dairy efficiency (Milk yield/DMI and ECM/DMI). As a percentage, milk fat, protein, and lactose were unchanged by RPL or RPLM but the yield of all components was increased (p<0.05) by feeding RPL while only milk protein was increased by feeding RPLM. Plasma Lys concentration was linearly increased (p<0.05) with increasing supplemental RPL while plasma Met increased (p<0.05) by RPLM supplementation. The increase in plasma Lys had a strong linear relationship (R² = 0.693 in the RPL dataset and R² = 0.769 in the RPLM dataset) on milk protein synthesis (g/d) during early lactation. Nitrogen metabolism parameters were not affected by feeding RPL or RPLM, either top-dress or when supplemented to deficient diets. Lactation performance did not differ between AA-deficient or AA-adequate diets in response to RPL or RPLM supplementation. Conclusion: RPL or RPLM showed a positive linear relationship on the lactational performance of dairy cows whereas greater improvement effects were observed during early lactation. Supplementing RPL or RPLM is recommended on deficient-AA diet but not on adequate-AA diet.

• 한국재료학회지
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• 제33권12호
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• pp.525-529
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• 2023

β-Ga₂O₃ has become the focus of considerable attention as an ultra-wide bandgap semiconductor following the successful development of bulk single crystals using the melt growth method. Accordingly, homoepitaxy studies, where the interface between the substrate and the epilayer is not problematic, have become mainstream and many results have been published. However, because the cost of homo-substrates is high, research is still mainly at the laboratory level and has not yet been scaled up to commercialization. To overcome this problem, many researchers are trying to grow high quality Ga₂O₃ epilayers on hetero-substrates. We used diluted SiH4 gas to control the doping concentration during the heteroepitaxial growth of β-Ga₂O₃ on c-plane sapphire using metal organic chemical vapor deposition (MOCVD). Despite the high level of defect density inside the grown β-Ga₂O₃ epilayer due to the aggregation of random rotated domains, the carrier concentration could be controlled from 1 × 10¹⁹ to 1 × 10¹⁶ cm^-3 by diluting the SiH4 gas concentration. This study indicates that β-Ga₂O₃ hetero-epitaxy has similar potential to homo-epitaxy and is expected to accelerate the commercialization of β-Ga₂O₃ applications with the advantage of low substrate cost.

• 한국환경보건학회지
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• 제49권6호
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• pp.305-311
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• 2023

Background: The National Institute of Environmental Research (NIER)'s classification of and airborne fraction ratio for consumer chemical products (CCP) does not reflect the characteristics of various product classifications. Objectives: The purpose of this study was to reclassify the types of spray products according to the diverse spray characteristics of CCPs to evaluate the airborne fraction ratio of representative spray types and to compare them with previous CCPs types and airborne fraction ratios. Methods: One thousand seven hundred two products were selected through market research, and 932 newly reported products were selected. After that, 200 were selected to evaluate products with potential inhalation exposure. After classifying six product types that are expected to show differences in the airborne fraction ratio according to the type of product, a final 38 products were selected for use in the airborne fraction ratio through random sampling. Results: CCP has been reclassified from two to six types so that the characteristics of all products are well-reflected. The NIER simply had two airborne fraction ratios, but the results of experiments with six types of products showed a significant difference in values (p<0.01). Airborne fraction ratios of propellant general foam, pump general aerosol, and pump trigger foam in spray type, which were not previously present in NIER, were 7.1%, 24.4%, and 3.5%, respectively. Conclusions: For the diversified types of CCPs, the newly proposed classification was more appropriate than the existing NIER classification. The airborne fraction ratio was also different for each type, so a new value was suggested.

• Journal of Animal Science and Technology
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• 제65권6호
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• pp.1180-1193
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• 2023

Most carcass and meat quality traits are moderate to highly heritable, indicating that they can be improved through selection. Genetic evaluation for these types of traits is performed using performance data obtained from commercial and progeny testing evaluation. The performance data from commercial farms are available in large volume, however, some drawbacks have been observed. The drawback of the commercial data is mainly due to sorting of animals based on live weight prior to slaughter, and this could lead to bias in the genetic evaluation of later measured traits such as carcass traits. The current study has two components to address the drawback of the commercial data. The first component of the study aimed to estimate genetic parameters for carcass and meat quality traits in Korean Hanwoo cattle using a large sample size of industry-based carcass performance records (n = 469,002). The second component of the study aimed to describe the impact of sorting animals into different contemporary groups based on an early measured trait and then examine the effect on the genetic evaluation of subsequently measured traits. To demonstrate our objectives, we used real performance data to estimate genetic parameters and simulated data was used to assess the bias in genetic evaluation. The results of our first study showed that commercial data obtained from slaughterhouses is a potential source of carcass performance data and useful for genetic evaluation of carcass traits to improve beef cattle performance. However, we observed some harvesting effect which leads to bias in genetic evaluation of carcass traits. This is mainly due to the selection of animal based on their body weight before arrival to slaughterhouse. Overall, the non-random allocation of animals into a contemporary group leads to a biased estimated breeding value in genetic evaluation, the severity of which increases when the evaluation traits are highly correlated.

• 한국군사과학기술학회지
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• 제27권1호
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• pp.116-125
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• 2024

The COVID-19 pandemic is not over despite the emergency use authorization as can see recent COVID-19 daily confirmed cases. The viruses are not only difficult to diagnose and treat due to random mutations, but also pose threat human being because they have the potential to be exploited as biochemical weapons by genetic manipulation. Therefore, it is inevitable to the rapid antibody-based therapeutic platform to quickly respond to future pandemics by new/re-emerging viruses. Although numerous researches have been conducted for the fast development of antibody-based therapeutics, it is sometimes hard to respond rapidly to new viruses because of complicated expression or purification processes for antibody production. In this study, a novel rapid antibody-based therapeutic platform using single B cell sorting method and mRNA-antibody. High immunogenicity was caused to produce antibodies in vivo through mRNA-antigen inoculation. Subsequently, antigen-specific antibody candidates were selected and obtained using isolation of B cells containing antibody at the single cell level. Using the antibody-based therapeutic platform system in this study, it was confirmed that novel antigen-specific antibodies could be obtained in about 40 days, and suggested that the possibility of rapid response to new variant viruses.

• 지식경영연구
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• 제25권1호
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• pp.155-172
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• 2024

이 연구의 목적은 가상환경에서의 다양한 환경 변화를 통한 외국어 학습 효과를 조사하는 것이다. 이를 위해 가상환경 공간을 교실과 식료품점으로 구분한 후, 여기에 각각 세 종류의 자막으로 구성된 텍스트 강화기법을 적용한 몰입형 가상현실 영어학습 콘텐츠를 직접 제작한 후 학습 효과를 비교했다. 실험은 2 × 3 혼합요인설계로 구성됐으며, 가상환경 공간은 실험자 내 요인으로 실험참여자는 학습 공간에 따라 처치 수준이 다른 두 개의 영상에 노출됐고, 텍스트 강화기법은 실험자 간 요인으로 실험참여자는 텍스트 강화기법에 따라 처치 수준이 다른 세 개의 자막 중 무작위로 한 개의 자막에 노출됐다. 가상환경 공간과 텍스트 강화기법에 따른 상호작용 효과 분석 결과, 프레즌스가 통계적으로 유의미한 차이를 보였다. 공간의 주효과를 살펴본 결과, 플로우와 학습 전-후 가상현실 교육 태도에 대해 통계적으로 유의미한 차이가 있었고, 텍스트 강화기법의 주효과를 분석한 결과, 플로우, 가상현실 학습 이용의도, 학습 만족도와 학습 자신감에서 통계적으로 유의미한 차이가 있었다. 결과적으로 가상현실 공간의 제공 환경에 따라 학습자의 교육에 대한 몰입과 태도 차이를 확인할 수 있었고, 자막 제공 방식에 따라 다양한 교육 효과의 차이가 있음을 확인할 수 있었다. 이는 가상환경에서 외국어 교육의 효과를 긍정적으로 확인한 것인데, 학교와 학원 등에서 가상환경을 활용한 영어학습 서비스의 가능성을 제시하고, 다양한 가상환경의 변화에 따라 교육 효과가 달라질 수 있다는 함의를 제공한다.