• 대한원격탐사학회지
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• 제38권1호
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• pp.21-32
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• 2022

The importance of the classical theme of how the Top-of-Atmosphere (TOA) and Top-of-Canopy (TOC) reflectance of high-resolution satellite images match the actual atmospheric reflectance and surface reflectance has been emphasized. Based on the Radiometric Calibration Network (RadCalNet) BTCN and BSCN data, this study compared the accuracy of TOA and TOC reflectance products of the currently available optical satellites, including KOMPSAT-3, WorldView-2, and Pléiades-1A image sets calculated using the absolute atmospheric correction function of the Orfeo Toolbox (OTB) tool. The comparison experiment used data in 2018 and 2019, and the Landsat-8 image sets from the same period were applied together. The experiment results showed that the product of TOA and TOC reflectance obtained from the three sets of images were highly consistent with RadCalNet data. It implies that any imagery may be applied when high-resolution reflectance products are required for a certain application. Meanwhile, the processed results of the OTB tool and those by the Apparent Reflection method of another tool for WorldView-2 images were nearly identical. However, in some cases, the reflectance products of Landsat-8 images provided by USGS sometimes showed relatively low consistency than those computed by the OTB tool, with the reference of RadCalNet BTCN and BSCN data. Continuous experiments on active vegetation areas in addition to the RadCalNet sites are necessary to obtain generalized results.

• 산업융합연구
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• 제19권6호
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• pp.49-57
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• 2021

디지털 사이니지와 다면 영상 시스템은 강한 몰입감으로 스토리와 정보를 전달하는 제4의 미디어로 사용되고 있다. 대형 디지털 사이니지에서 상영되는 콘텐츠는 주로 실사 영상보다는 컴퓨터 그래픽을 이용한 영상으로 제작되고 있다. 그 이유 중 하나는 콘텐츠 제작을 위해 촬영된 영상을 사용하려면 제작범위가 극히 제한적이고 고해상도 실사 촬영의 한계로 크고 넓게 구성된 디지털 사이니지 화면에서 고화질 재현에 무리가 많기 때문이다. 반면 영화 상영관 중앙에 있는 스크린과 좌, 우측 벽면을 스크린으로 활용한 Screen X와 Escape는 디지털 시네마용 카메라 3대로 실사 촬영하여 스티칭 작업 후 다면 영상 시스템을 갖춘 극장에서 실감 영상으로 상영되는데 관객들에게 많은 실감 체험을 주고 있다. 이번 연구는 Screen X의 다면 영상 촬영 제작기술과 크로마키 기법을 이용하여 고해상도로 촬영된 영상을 디지털 사이니지에서 화질 열화 없이 상영할 수 있을 것이다.

• 한국콘텐츠학회논문지
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• 제22권10호
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• pp.506-514
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• 2022

형벌을 중심으로 처벌을 통해 재범을 억제하고자 하는 방식은 다수국가들의 형사정책 연구를 통해 그 한계가 나타나고 있다. 이에 대한 대안으로 지역사회구성원과 피해자, 가해자의 화해와 조정을 통해 범죄자가 사회의 일원으로 복귀하는 것을 목적으로 하는 회복적 사법이 범죄 및 재범방지의 패러다임으로 등장하고 있다. 스웨덴은 대표적인 복지국가이자 회복적 사법에 기반한 범죄자 교정을 통해 긍정적인 효과를 확인하고 있다. 또한, 법무보호복지제도와 관련해 안정된 체계를 갖추고 있으며, 운영프로그램의 평가와 인증 과정에서 증거기반의 원칙을 활용한 과학적이고 합리적인 운영으로 낮은 재범률과 사회보장을 유지하고 있다. 그러나 아직 국내에서는 스웨덴을 비롯한 복지 및 교정 선진국에서 시행되는 법무보호복지제도에 대한 연구가 미흡한 실정이다. 이에 본 연구는 스웨덴의 범죄정책과 법무보호복지제도에 관한 고찰을 통해 국내 법무보호복지제도가 나아갈 방향을 탐색하고 국내 제도의 미진한 영역 및 보완점을 파악하여 국내 법무보호복지제도의 개선 및 사업 확대를 위한 토대를 마련하고자 한다.

• Physical Therapy Rehabilitation Science
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• 제9권4호
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• pp.230-237
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• 2020

Objective: To investigate the physical appearance and therapeutic changes that occur with the performance of Schroth exercise in patients with scoliosis. Design: Randomized controlled trial. Methods: Fifteen subjects with maximum curvature of the lumbar who were diagnosed with idiopathic scoliosis had volunteered to participate in the study. Eight subjects were included in the experimental group where they performed the Schroth Therapeutic Exercise and the other seven were included in the control group. The experimental group underwent 2 hours of weekly treatment for 12 weeks, while the control group did not during the same period based on the decisions of patients or guardians. The Mann-Whitney rank test was carried out to compare the treatment results of the two groups, and the comparison within the group was done by Wilcoxon signed-rank test. The vertebral rotation angle (VRA) was by Scoliometer, and difference of rotated and curved portion volume (DV) between both sides on the major curvature portion measured by 3D human body scanning system. Results: In the experimental group, 12 weeks of Schroth exercise therapy has significant improved in correction rate (CR) in Cobb's angle (CA), VRA, and DV between both sides on the major curvature portion (p<0.05), while significant differences were not found between the groups regarding weight bearing difference in both feet (WD) and DV (p<0.05). Conclusions: Schroth exercise performance showed significant changes in the patient's therapeutic changes (CA, VRA), but the physical appearance (DV, WD) was not significant, indicating that external changes in the treatment goal setting are more difficult goals to achieve.

• 문화기술의 융합
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• 제7권2호
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• pp.427-436
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• 2021

본 연구의 목적은 문학 텍스트를 학습한 머신 러닝 언어 모델을 구현하는데 있다. 문학 텍스트는 일상 대화문처럼 질문에 대한 답변이 분명하게 구분되지 않을 때가 많고 대명사와 비유적 표현, 지문, 독백 등으로 다양하게 구성되어 있다는 특징이 있다. 이런 점들이 알고리즘의 학습을 용이하지 않게 하여 문학 텍스트를 활용하는 기계 학습의 필요성을 저해시킨다. 문학 텍스트를 학습한 알고리즘이 일반 문장을 학습한 알고리즘에 비해 좀 더 인간 친화적인 상호작용을 보일 가능성이 높다. 본 논문은 '문학 텍스트를 학습한 머신 러닝 언어 모델 구현'에 관한 연구로서, 대화형 기계 학습에 문학 텍스트를 활용하는 연구에서 필수적으로 선행되어야 할 세 가지 텍스트 보정 작업을 제안한다: 대명사 처리, 대화쌍 늘리기, 데이터 증폭 등에 대한 내용으로 기계 학습이 용이하고 그 효과도 높다고 판단됩니다. 인공지능을 위한 학습용 데이터는 그 의미가 명료해야 기계 학습이 용이하고 그 효과도 높게 나타난다. 문학과 같은 특수한 장르의 텍스트를 자연어 처리 연구에 도입하는 것은 새로운 언어 학습 방식의 제안과 함께 머신 러닝의 학습 영역도 확장시켜 줄 것이다.

• Steel and Composite Structures
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• 제41권6호
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• pp.899-910
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• 2021

A 4-unknown shear deformation theory is applied to investigate the vibration of functionally graded plates under thermal environment. The plate is fabricated from a functionally graded material mixed of ceramic and metal with continuously varying material properties through the plate thickness. Three types of thermal loadings, uniform, linear and nonlinear temperature rises along the plate thickness are taken into account. The present theory contains four unknown functions as against five or more in other higher order shear deformation theories. The through-the-thickness distributions of transverse shear stresses of the plate are considered to vary parabolically and vanish at upper and lower surfaces. The present model does not require any problem dependent shear correction factor. Analytical solutions for the free vibration analysis are derived based on Fourier series that satisfy the boundary conditions (Navier's method). Benchmark solutions are firstly considered to evaluate the accuracy of the proposed model. Comparisons with the solutions available in literature revealed the good capabilities of the present model for the simulations of vibration responses of FG plates. Some parametric studies are carried out for the frequency analysis by varying the volume fraction profile and the temperature distribution across the plate thickness.

• Steel and Composite Structures
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• 제43권6호
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• pp.821-837
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• 2022

This research is devoted to study the effects of humidity and temperature on the bending behavior of functionally graded (FG) ceramic-metal porous plates resting on Pasternak elastic foundation using a quasi-3D hyperbolic shear deformation theory developed recently. The present plate theory with only four unknowns, takes into account both transverse shear and normal deformations and satisfies the zero traction boundary conditions on the surfaces of the functionally graded plate without using shear correction factors. Material properties of porous FG plate are defined by rule of the mixture with an additional term of porosity in the through-thickness direction. The governing differential equations are obtained using the "principle of virtual work". Analytically, the Navier method is used to solve the equations that govern a simply supported FG porous plate. The obtained results are checked by comparing the results determined for the perfect and imperfect FG plates with those available in the scientific literature. Effects due to material index, porosity factors, moisture and thermal loads, foundation rigidities, geometric ratios on the FG porous plate are all examined. Finally, this research will help us to design advanced functionally graded materials to ensure better durability and efficiency for hygro-thermal environments.

• 한국해양공학회지
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• 제36권1호
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• pp.32-40
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• 2022

Underwater optical images face various limitations that degrade the image quality compared with optical images taken in our atmosphere. Attenuation according to the wavelength of light and reflection by very small floating objects cause low contrast, blurry clarity, and color degradation in underwater images. We constructed an image data of the Korean sea and enhanced it by learning the characteristics of underwater images using the deep learning techniques of CycleGAN (cycle-consistent adversarial network), UGAN (underwater GAN), FUnIE-GAN (fast underwater image enhancement GAN). In addition, the underwater optical image was enhanced using the image processing technique of Image Fusion. For a quantitative performance comparison, UIQM (underwater image quality measure), which evaluates the performance of the enhancement in terms of colorfulness, sharpness, and contrast, and UCIQE (underwater color image quality evaluation), which evaluates the performance in terms of chroma, luminance, and saturation were calculated. For 100 underwater images taken in Korean seas, the average UIQMs of CycleGAN, UGAN, and FUnIE-GAN were 3.91, 3.42, and 2.66, respectively, and the average UCIQEs were measured to be 29.9, 26.77, and 22.88, respectively. The average UIQM and UCIQE of Image Fusion were 3.63 and 23.59, respectively. CycleGAN and UGAN qualitatively and quantitatively improved the image quality in various underwater environments, and FUnIE-GAN had performance differences depending on the underwater environment. Image Fusion showed good performance in terms of color correction and sharpness enhancement. It is expected that this method can be used for monitoring underwater works and the autonomous operation of unmanned vehicles by improving the visibility of underwater situations more accurately.

• Steel and Composite Structures
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• 제43권2호
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• pp.271-278
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• 2022

Buckling is one of the most critical phoneme in the design of steel structures. Lateral torsional buckling (LTB) is particularly significant for slender beams generally subjected to loading in plane. The web distortion effects on LTB are not addressed explicitly in standards for flexural design of steel I-section members. Hence, the present study is focused to predict the influence of the web distortion on the elastic (L_r) limiting lengths given in American Institute of Steel Construction (AISC) code for the lateral torsional buckling (LTB) behavior of steel beams due to no provision in the code for consideration of web distortion. For this aim, the W44x335 beam is adopted in the buckling analysis carried out by the ABAQUS finite element (FE) program since it is one of the most critical sections in terms of lateral torsional buckling (LTB). The strain results at mid-height of the web at mid-span of the beam are taken into account as the monitoring parameters. The web strain results are found to be relatively greater than the yield strain value when L/L_r is equal to 1.0. In other words, the ratio of L/L_r is estimated from the numerical analysis to be about 1.5 when the beam reaches its first yielding at mid-span of the beam at mid-height of the section. Due to the effect of web distortion, the elastic limiting length (L_r) from the numerical analysis is obtained to be considered as greater than the calculated length from the code formulation. It is suggested that the formulations of the limiting length proposed in the code can be corrected considering the influence of the web distortion. This correction can be a modification factor or a shape factor that reduces sectional slenderness for the LTB formulation in the code.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제3권4호
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• pp.191-198
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• 2022

Natural habitats of the Korean long-tailed goral (Naemorhedus caudatus) have been fragmented by anthropogenic activities in South Korea in the last decades. Here, the individual identity, genetic variation, and population differentiation of the endangered species were examined via the multiple-tube approach using a non-invasive genotyping method. The average number of alleles was 3.16 alleles/locus for the total population. The Yanggu population (1.66) showed relatively lower average number of alleles than the Inje population (3.67). Of the total 19 alleles, only seven (36.8%) alleles were shared by the two populations. Using five polymorphic out of six loci, four and six different goral individuals from the captive Yanggu (n=24) and the wild Inje (n=28) population were identified, respectively. The allele distribution was not identical between the two populations (Fisher's exact test: P<0.01). A considerably low migration rate was detected between the two populations (no. of migrants after correction for size=0.294). Additionally, the F statistics results indicated significant population differentiation between them, however, quite low (F_ST=0.327, P<0.01). The posterior probabilities indicated that the two populations originated from a single panmictic population (P=0.959) and the assignment test results designated all individuals to both populations with nearly equal likelihood. These could be resulted from moderate population differentiation between the populations. No significant evidence supported recent population bottleneck in the total Korean goral population. This study could provide us with useful population genetic information for conservation and management of the endangered species.