• Nuclear Engineering and Technology
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• 제41권5호
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• pp.729-738
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• 2009

Given the evolution of High-Temperature Gas-cooled Reactor(HTGR) designs, the source terms for licensing must be developed. There are three potential source terms: fission products, actinides in the fuel and tritium in the coolant. It is necessary to provide first an inventory of the source terms under normal operations. An analysis of source terms has yet to be performed for HTGRs. The previous code, which can estimate the inventory of the source terms for LWRs, cannot be used for HTGRs because the general data of a typical neutron cross-section and flux has not been developed. Thus, this paper uses a combination of the MCNP, ORIGEN, and MONTETEBURNS codes for an estimation of the source terms. A method in which the HTR-10 core is constructed using the unit lattice of a body-centered cubic is developed for core modeling. Based on this modeling method by MCNP, the generation of fission products, actinides and tritium with an increase in the burnup ratio is simulated. The model developed by MCNP appears feasible through a comparison with models developed in previous studies. Continuous fuel management is divided into five periods for the feeding and discharging of fuel pebbles. This discrete fuel management scheme is employed using the MONTEBURNS code. Finally, the work is investigated for 22 isotope fission products of nuclides, 22 actinides in the core, and tritium in the coolant. The activities are mainly distributed within the range of $10^{15}{\sim}10^{17}$ Bq in the equilibrium core of HTR-10. The results appear to be highly probable, and they would be informative when the spent fuel of HTGRs is taken into account. The tritium inventory in the primary coolant is also taken into account without a helium purification system. This article can lay a foundation for future work on analyses of source terms as a platform for safety assessment in HTGRs.

• 응용통계연구
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• 제27권1호
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• pp.21-30
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• 2014

치유율 모형(cure rate model)은 위험 그룹의 단조 감소에 대한 가정이 부적절한 경우에 적용될 수 있다. 예를 들어, 생존 분석에서 위험 그룹은 시간이 경과함에 따라 점점 감소하여 무한대의 시간대에는 영으로 수렴하며 이는 곧 생존 함수가 영으로 수렴함을 의미한다. 하지만 이러한 가정이 적합하지 못한 자료가 의약학, 사회학, 경제학 등에서 종종 발생된다. 즉, 어느 시점에 이르러 더 이상의 생존함수는 감소하지 않고 평행선을 보여주는 경우에 로그 순위검정(log rank test)과 Cox's 비례위험모형(proportional hazard model)의 적용은 바람직하지 못한 결론을 가져오게 된다. 이러한 자료에 대해 치유율 모형(cure rate model)에서는 사건 발생 취약 그룹(susceptible group)과 비취약 그룹(insusceptible group)으로 나누어 취약그룹에 대해서만 일반적인 생존 분석 방법을 적용하는 혼합 모형(mixture model)을 적용해왔다 (Berkson과 Gage, 1952). 본 연구에서는 이러한 치유율 모형을 군집화 구간 중도 절단 자료(clustered interval censored data)에 적용해 보고자 한다. 최근에 Kim과 Jhun (2008)은 구간 중도 절단자료에 대해 치유율 모형을 적용하였으며 본 연구에서는 그들의 방법을 군집화 자료로 확장할 것이다. 실제 자료 분석의 예로 금연자료를 분석할 것이다.

• 복식
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• 제63권8호
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• pp.125-142
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• 2013

Soek(Xi) was the highest ranked shoe that was worn with the primary formal dress in East Asian countries including ancient Korea and China. This article examined Joseon's Seok as discussed in previous studies, and it explored factors such as the wearers' status, wearing situations, its morphology, its materials, and its colors in the Great Han Empire period (1897~1910), and then extracted three morphological characteristics of the Korean Seok to examine its origin. The results of the study are as follows. For women, the Seok in the Great Han Empire period was worn with Won-sam(圓衫) and No-eui(露衣) as well as Jeok-eui(翟衣), and hence its range of wearing was extensive. Also, red Seok was worn with deep red colored Dae-sam(大衫)-styled Jeok-eui in the Joseon period(1392~1897), and blue Seok with deep blue Jeok-eui in the Great Han Empire period. This suggests the possibility that wearing of deep blue Jeok-eui occurred after 1906 in terms of the use of blue Seok. As for its morphology, its leg-less form was maintained into the late Joseon period, and there were no great changes in its name. The characteristics of the Korean Seok's morphological structure consisted of a shoe leg, the wood-less bottom and pearl ornament. As a result of the examination of the origin of those characteristics, it has been clarified that the form in which Gu, Eok, Jun(純), are attached in the structure with a shoe leg originated from the combination of Hwa(靴) and Li(履) after the two types of shoes were alternately worn in the Song (宋) period. Also, it was confirmed that the woodless bottom appeared between the periods from Wei Jin Northern and Southern Dynasties(魏晉南北朝) to Sui(隋), and the pearl ornament occurred in the Jin(金) period.

• Journal of Astronomy and Space Sciences
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• 제37권2호
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• pp.143-156
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• 2020

Korea Polar Research Institute (KOPRI) installed an ionospheric sounding radar system called Vertical Incidence Pulsed Ionospheric Radar (VIPIR) at Jang Bogo Station (JBS) in 2015 in order to routinely monitor the state of the ionosphere in the auroral oval and polar cap regions. Since 2017, after two-year test operation, it has been continuously operated to produce various ionospheric parameters. In this article, we will introduce the characteristics of the JBS-VIPIR observations and possible applications of the data for the study on the polar ionosphere. The JBS-VIPIR utilizes a log periodic transmit antenna that transmits 0.5-25 MHz radio waves, and a receiving array of 8 dipole antennas. It is operated in the Dynasonde B-mode pulse scheme and utilizes the 3-D inversion program, called NeXtYZ, for the data acquisition and processing, instead of the conventional 1-D inversion procedure as used in the most of digisonde observations. The JBS-VIPIR outputs include the height profiles of the electron density, ionospheric tilts, and ion drifts with a 2-minute temporal resolution in the bottomside ionosphere. With these observations, possible research applications will be briefly described in combination with other observations for the aurora, the neutral atmosphere and the magnetosphere simultaneously conducted at JBS.

• Smart Structures and Systems
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• 제21권4호
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• pp.421-433
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• 2018

Carbon fiber reinforced polymer (CFRP) cable has good mechanical properties and corrosion resistance. However, the anchorage of CFRP cable is a big issue due to the anisotropic property of CFRP material. In this article, a high-efficient bonding anchorage with novel configuration is developed for CFRP cables. The acoustic emission (AE) technique is employed to evaluate the performance of anchorage in the fatigue test and post-fatigue ultimate bearing capacity test. The obtained AE signals are analyzed by using a combination of unsupervised K-means clustering and supervised K-nearest neighbor classification (K-NN) for quantifying the performance of the anchorage and damage evolutions. An AE feature vector (including both frequency and energy characteristics of AE signal) for clustering analysis is proposed and the under-sampling approaches are employed to regress the influence of the imbalanced classes distribution in AE dataset for improving clustering quality. The results indicate that four classes exist in AE dataset, which correspond to the shear deformation of potting compound, matrix cracking, fiber-matrix debonding and fiber fracture in CFRP bars. The AE intensity released by the deformation of potting compound is very slight during the whole loading process and no obvious premature damage observed in CFRP bars aroused by anchorage effect at relative low stress level, indicating the anchorage configuration in this study is reliable.

• Genomics & Informatics
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• 제17권4호
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• pp.47.1-47.12
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• 2019

The achievements of genome-wide association studies have suggested ways to predict diseases, such as type 2 diabetes (T2D), using single-nucleotide polymorphisms (SNPs). Most T2D risk prediction models have used SNPs in combination with demographic variables. However, it is difficult to evaluate the pure additive contribution of genetic variants to classically used demographic models. Since prediction models include some heritable traits, such as body mass index, the contribution of SNPs using unmatched case-control samples may be underestimated. In this article, we propose a method that uses propensity score matching to avoid underestimation by matching case and control samples, thereby determining the pure additive contribution of SNPs. To illustrate the proposed propensity score matching method, we used SNP data from the Korea Association Resources project and reported SNPs from the genome-wide association study catalog. We selected various SNP sets via stepwise logistic regression (SLR), least absolute shrinkage and selection operator (LASSO), and the elastic-net (EN) algorithm. Using these SNP sets, we made predictions using SLR, LASSO, and EN as logistic regression modeling techniques. The accuracy of the predictions was compared in terms of area under the receiver operating characteristic curve (AUC). The contribution of SNPs to T2D was evaluated by the difference in the AUC between models using only demographic variables and models that included the SNPs. The largest difference among our models showed that the AUC of the model using genetic variants with demographic variables could be 0.107 higher than that of the corresponding model using only demographic variables.

• Clinical and Experimental Pediatrics
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• 제46권2호
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• pp.198-202
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• 2003

국내 소아에서는 아직 화학 물질 흡입화상에 대한 보고가 없는 상태로 저자들은 수영장 창고에서 수영장 물의 살균, 소독제인 이염화이소시안산 나트륨과 차아염소산 칼슘을 잘못 혼합하던 중 발생한 소독제 분말 가스 폭발 반응에 노출되어 급격한 호흡 곤란증이 있었던 증례 2례를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권3호
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• pp.215-219
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• 2012

Cemento-ossifying fibroma (COF) is a benign fibro-osseous tumor with fibrous tissue, abnormal cement and bone, or a combination of such elements. These are slow-growing lesions and are more frequent in women. Here, we report the case of a 28-year-old Korean woman. The patient having no underlying disease complained about facial swelling and asymmetry. A firm mass with impacted molars and teeth deviation on the right maxilla was observed. A computed tomography scan was taken and an incisional biopsy was performed. Following this, COF was diagnosed. Complete surgical removal of the lesion was carried out. A post-operative follow-up was conducted and 3 months later the patient reported no discomfort or any sign of recurrence in regards to the lesion. Differential diagnosis with fibrous dysplasia and the COF is important because of the treatment choice. We report a case of COF and offer a review of the literature on this article.

• Journal of the Korean Data and Information Science Society
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• 제20권2호
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• pp.329-338
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• 2009

중요도-실행도 분석은 성취도나 만족도에 관련된 의사결정이 필요한 다양한 분야에서 사용되는 간단하면서 함축적인 분석방법이다. 그 효과와 활용성이 많은 연구에 의하여 증거 되고 있으며, 통계학적인 면에서 연구할 여지가 많이 있다고도 사려 된다. 본 연구는 중요도-실행도 분석에 대한 몇 가지 부가적인 분석 방법을 소개하고 보다 정교한 정보들을 얻어낼 수 있음을 예를 통해 보였다. 중요도-실행도 분석은 산술평균을 기본 통계량으로 사용하고 있으나 중간값, 빈도, 군집 분석을 통한 자료 필터링을 통해 보다 핵심적인 정보에 기반 하는 중요도-실행도 분석을 실시하였다. 추가적으로 계층화 분석을 중요도-실행도 분석과결합하여 보다 적극적인의사결정이 가능함을 보였다.

• 한국가구학회지
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• 제24권2호
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• pp.183-190
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• 2013

This article intends to explore the formation of furniture terms with the name of furniture, furniture materials, tools, and machinery from eight furniture companies manufacturing their own different furniture items. As a result of this study, the terms can be abstracted as four things as follows. First of all, the terminology that the furniture firms is are unified over 80 percent and has no problem on the communication among the companies. Especially office furniture all is using common words because the terms are almost fixed by an administration agreement relating to the Supply Administration. Second, the furniture terms being used at the fields are mixed with Korean, English, and Japanese, and this current state shows more at small businesses than at large businesses Third, the terms of foreign words, almost English, present 48 percent as 156 words among the total 325 terms. Japanese shows 6 percent as 21 terms but it tends to be handed down from mouth to mouth with inaccurate conditions. Finally, the formation of the terms are from the original words or English, from the combination of Korean and foreign words for convenience at the fields, and from being created as Korean newly in considering Korea's special situation.