• 한국환경과학회지
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• 제11권7호
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• pp.663-667
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• 2002

The aerodynamic resistance($R_a$) to vertical transfer in the surface boundary layer can be formulated in terms of the friction velocity, height of observation, vertical heat flux and surface roughness. Unlike previous studies which focused on the role of $R_c$, present study perform additional tests using a variety of $R_a$ formulae. Several $R_a$ formulations available in the literature, suitable for unstable conditions, were tested for their influence on the dry deposition velocity. The canopy resistance($R_c$) determines the shape of the diurnal pattern, while a small amplitude diurnal cycle in $V_d$ was attributed to the aerodynamic resistance. The aerodynamic resistance is the major contributor to the formation of spikes in nighttime and $R_a$ is relatively important at night because the canopy resistance is smaller. All formulations show similar diurnal cycle and yield good agreement with the observations. Although present $V_d$ formulations are suitable for numerical air qualify models, the research must continue for further improvements in resistance parametrizations.

• 한국주조공학회지
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• 제20권2호
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• pp.110-115
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• 2000

In this study, the powders of Mg-3wt%Al-1wt%Zn-1wt%MM alloy were produced under vacuum condition by the inert gas atomization and the rapidly solidified powders were consolidated by the vacuum hot extrusion. Then the structural change of powders during extrusion was investigated. The effects of misch metal addition to AZ31 on mechanical properties of extruded bars were also examined. During extrusion of the rapidly solidified powders, their dendrite structure was broken into fragments and remained as grains of 2 ${\mu}m$ size in extruded bar. The Mg-Al-Ce intermetallic compounds formed in the interdendritic regions of powders were broken finely, too. The yield stress, tensile strength and ductility obtained in as-extruded Mg-3wt%Al-1wt%Zn-1wt%MM alloy were ${\sigma}_{0.2}=325$ MPa, ${\sigma}_{T.S.}=417$ MPa and ${\varepsilon}=16.8%$. All of these improvements on mechanical properties result from the refined micostructure and second-phase dispersions.

• 한국정보통신학회논문지
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• 제12권11호
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• pp.2039-2044
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• 2008

FIR 필터, DCT, FFT와 같은 디지털 신호처리 응용에서 다중 고정 계수 곱셈의 효율적인 하드웨어 구현문제에 자주 접하게 된다. 고정계수 곱셈기 설계에서 공통 하위식 제거 알고리즘은 면적과 전력소모를 상당히 개선시킬 수 있는 방법을 제공한다. 본 논문에서는 CSD 계수에서 빈번히 나타나는 두 공통 하위식($10{\bar{1}}$, 101)의 덧셈을 수행하는 전용덧셈기 설계 방법을 제안한다. 제안한 방법을 radix-24 FFT 구조의 고정계수 곱셈블록에 적용한 실험에서 제안한 방법의 면적, 지연시간, 전력소비는 기존방법 보다 각각 21%, 11%, 12% 정도 향상됨을 보인다.

• 정보보호학회논문지
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• 제28권6호
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• pp.1499-1508
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• 2018

빠른 속도로 성장하고 있는 전자상거래 시장이 기업들에게 고객층을 넓혀나갈 좋은 기회를 제공하고 있는 반면에 블랙컨슈머로 인한 기업들의 피해 사례 또한 늘어나고 있다. 본 연구는 전자상거래 고객 데이터를 통해 전자상거래상의 블랙컨슈머를 탐지해내는 머신 러닝 모델을 구축하고 최적화하는 것을 목표로 한다. Feature selection의 filter method와 4개의 classification 알고리즘을 이용한 실험을 통해 F-measure 0.667의 정확도로 블랙컨슈머를 탐지하는 모델을 구축하였으며 F-measure에서 11.44%, AURC에서 10.51%, TPR에서 22.87%의 성능 향상을 확인 할 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권8호
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• pp.3942-3961
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• 2019

Recently, the models of deep super-resolution networks can successfully learn the non-linear mapping from the low-resolution inputs to high-resolution outputs. However, for large scaling factors, this approach has difficulties in learning the relation of low-resolution to high-resolution images, which lead to the poor restoration. In this paper, we propose Stage Generative Adversarial Networks (Stage-GAN) with semantic maps for image super-resolution (SR) in large scaling factors. We decompose the task of image super-resolution into a novel semantic map based reconstruction and refinement process. In the initial stage, the semantic maps based on the given low-resolution images can be generated by Stage-0 GAN. In the next stage, the generated semantic maps from Stage-0 and corresponding low-resolution images can be used to yield high-resolution images by Stage-1 GAN. In order to remove the reconstruction artifacts and blurs for high-resolution images, Stage-2 GAN based post-processing module is proposed in the last stage, which can reconstruct high-resolution images with photo-realistic details. Extensive experiments and comparisons with other SR methods demonstrate that our proposed method can restore photo-realistic images with visual improvements. For scale factor ${\times}8$, our method performs favorably against other methods in terms of gradients similarity.

• Earthquakes and Structures
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• 제22권6호
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• pp.585-595
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• 2022

Using the nonlinear static procedures has become very common in seismic codes to achieve the nonlinear response of the structure during an earthquake. The capacity spectrum method (CSM) adopted in ATC-40 is considered as one of the most known and useful procedures. For this procedure the seismic demand can be approximated from the maximum deformation of an equivalent linear elastic Single-Degree-of-Freedom system (SDOF) that has an equivalent damping ratio and period by using an iterative procedure. Data from the results of this procedure are plotted in acceleration- displacement response spectrum (ADRS) format. Different improvements have been made in order to have more accurate results compared to the Non Linear Time History Analysis (NL-THA). A new procedure is presented in this paper where the iteration process shall not be required. This will be done by estimation the ductility demand response spectrum (DDRS) and the corresponding effective damping of the bilinear system based on a new parameter of control, called normalized yield strength coefficient (η), while retaining the attraction of graphical implementation of the improved procedure of the FEMA-440. The proposed procedure accuracy should be verified with the NL-THA analysis results as a first implementation. The comparison shows that the new procedure provided a good estimation of the nonlinear response of the structure compared with those obtained when using the NL-THA analysis.

• 대한한방내과학회지
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• 제44권5호
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• pp.948-956
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• 2023

The purpose of this study is to report a case of cervical dystonia and the effects of a series of traditional Korean medicine treatments applied to the patient. The patient was treated with conventional treatment and traditional Korean medicine consisting of acupuncture, moxa, chuna therapy, and herbal medicine (Hoesu-san-gami) for 48 days. Progress was measured by Tsui's score, the Toronto Western Spasmodic Torticollis Rating Scale, and the Neck Disability Index. We observed some improvements in the patient's symptoms: Tsui's score of 15 to 11, TWSTRS of 63.3 to 47.8, and NDI of 24 to 17. These findings indicate that the application of traditional Korean medicine to cervical dystonia can yield decent clinical outcomes.

• Clinical Endoscopy
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• 제57권4호
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• pp.434-445
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• 2024

Pancreatic cystic lesions (PCLs) have increased in prevalence due to the increased usage and advancements in cross-sectional abdominal imaging. Current diagnostic techniques cannot distinguish between PCLs requiring surgery, close surveillance, or expectant management. This has increased the morbidity and healthcare costs from inappropriately aggressive and conservative management strategies. Endoscopic ultrasound (EUS) needle-based confocal laser endomicroscopy (nCLE) allows for microscopic examination and delineation of the surface epithelium of PCLs. Landmark studies have identified characteristics distinguishing various types of PCLs, confirmed the high diagnostic yield of EUS-nCLE (especially for PCLs with an equivocal diagnosis), and shown that EUS-nCLE helps to change management and reduce healthcare costs. Refining procedure technique and reducing procedure length have improved the safety of EUS-nCLE. The utilization of artificial intelligence and its combination with other EUS-based advanced diagnostic techniques would further improve the results of EUS-based PCL diagnosis. A structured training program and device improvements to allow more complete mapping of the pancreas cyst epithelium will be crucial for the widespread adoption of this promising technology.

• 한국작물학회지
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• 제63권1호
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• pp.64-71
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• 2018

간척지 토양 환경을 개선하기 위하여 절단케나프, 팽연왕겨, 볏짚, 펠릿퇴비 등 유기물원을 10a당 3,000 kg씩 투입하였다. 투입 결과 간척지 토양 염농도(EC)는 1.2 dS/m에서 0.5 dS/m로 58%로 감소하였으며 토양 유기물 함량은 6.7 g/kg에서 16.0 g/kg으로 1.4배 증가하였다. 토양 공극은 유기물 투입 평균 47.9%로 비투입에 비해 10.2%p 증가하였다. 토양 경도는 20.2 mm에서 17.9 mm로 11.4% 감소하였으며 작토심은 19.8 cm에서 26.8 cm로 35% 깊어졌다. 간척지 토양 이화학성 개선 효과에 의하여 작물 생육이 향상 되었는데 간척지에 유기물을 투입하고 재배한 케나프의 초장이 비투입 처리에 비해 18.8% 더 성장하였으며 펠릿퇴비와 볏짚 처리에서의 성장 효과가 뚜렷하였다. 생육 향상에 의해 수량도 증가하였는데 간척지에서 유기물을 투입하고 케나프를 재배한 결과 평균 수량이 9,218 kg/10a로 무투입 4,368 kg/10a의 2.1배 까지 증가하였다. 수량 증가를 위해 가장 적절한 유기물원은 펠릿퇴비이었는데 10a당 수량이 10,848 kg/10a로 무투입 대비 148% 높았으며, 볏짚($120%{\uparrow}$), 절단케나프($95%{\uparrow}$) 순으로 수량 증가 효과가 있었다. 간척지 토양 이화학성 개선 효과를 강화시키기 위하여 펠릿형, 분말형, 액비형태로 퇴비 투입 형태를 달리하여 처리한 결과 토양 이화학성 개선에 가장 효과적인 형태는 펠릿형 이었다. 퇴비 투입 형태중 케나프 생육 및 수량 향상에 적합한 퇴비 형태는 액비형과 펠릿형 이었는데 펠릿형 처리시 케나프 초장은 41% 커지고 수량은 122% 증가하였으며 액비형은 38%의 생육 촉진과 무투입 대비 127% 수량 증가효과를 나타내었다.

• Journal of Animal Science and Technology
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• 제46권5호
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• pp.773-782
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• 2004

본 연구는 산차와 비유기가 다양한 Holstein 종 56두를 사용하여 사료섭취량과 에너지요구 량을 근거로 개체별 사료에너지요구량의 서열을 설정하고, 이를 3개 우군으로 나누어 각 우군의 상반평균치에 기준하여 자가배합사료(herdmix ration)를 조제한 후 이것을 이용한 사양체계가 비유기 및 산차에 미치는 영향을 관행 사양체계와 switch-over method로 비교하였다. 자가배합사료 급여체계는 전 비유기 동안 산유량과 유지율을 증진시켰으며(P<0.05), 산차별 생산능력도 모든 산차에서 향상되었다(P<0.05). 비유단계별 성적에서는 비유초기와 중기에서 Herd-mix구의 설제산유량(AMY) 및 지방보정유량(FCM)이 유의적으로 증가하였으나(P<0.05) 유지율은 유의차가 없었다. 비유말기에는 AMY, 유지율 및 FCM 모두 Herd-mix구가 관행구에 비하여 증가하였으며 특히 유지율과 FCM이 현저하게 증가하였다(P<0.01). Herd-mix구와 관행구의 FCM 비유지속성은 각각 93.24%와 92.69%로서 Herd-mix구의 비유지속성이 높았으며 비유곡선의 형태도 이상적 추세를 보였다. 유대와 사료비를 고려한 조수익을 산출한 결과 Herd-mix구가 관행구보다 40% 높았다. 결론적으로, 본 연구는 젖소의 에너지요구량과 사료 에너지 농도를 정확히 평가하여 우군을 편성한 후 그 상반평균을 배합목표로 설정하고 사용할원료에 대한 실질적인 평가를 근거로 배합비를 설정하는 것이 산유능력을 향상시킴과 동시에 경제적으로 유려하다는 사실을 입증하였다.