• Korean Journal of Heritage: History & Science
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• v.51 no.2
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• pp.92-107
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• 2018

In 2013~2016, gilt-bronze shoes were excavated from the ancient tombs in Jeongchon Village located at Bogam-ri, Dasi-myeon in Naju. They are estimated to have been made in the late 5th or early 6th centuries. The gilt-bronze shoes are significant in that they serve to explicate the relationship between the center of Baekje and the local forces in the Yeongsan River Basin. This study's specific focus was the gilt-bronze shoes from the ancient tombs in Jeongchon Village. Based on the findings, a restoration drawing was designed and restored products were manufactured by considering metalwork techniques used to manufacture the original ones. At first, manufacturing techniques were tested by using a scientific analysis and visual observation. The manufacturing method, structures, and patterns of the gilt-bronze shoes were closely examined. Then, a design drawing of gilt-bronze shoes was created through field measurement and they were recreated on the basis of the analysis. The original form of the restored products were manufactured through cutting out the outward form, bore carving, engraving, molding, plating, and an assembly process. In the restoration process, this study examined the formal characteristics of gilt-bronze shoes, manufacturing techniques, and archetypes during Baekje's late Hanseong era. Products restored from this study are expected to be used as achievements for more easily understanding the culture of Baekje.

• Proceedings of the Korean Society for Information Management Conference
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• 2017.08a
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• pp.103-103
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• 2017

생태학 분야에서는 생물의 분포, 변동, 서식환경요인의 변화, 등의 여러 종류의 데이터들이 수집되고 있는데 데이터의 형태가 다양하여 데이터의 관리와 활용형태도 다양하게 나타나고 있다. 근래에 들어 각 종 측정기기들이 개발되면서 생태조사 분야에서도 데이터의 양이 급증하는 시점에 있다. 수생태계 분야에서도 전통적인 생물상조사의 데이터는 크게 증가하지 않고 있지만 자동측정센서가 개발된 항목의 경우에는 데이터가 급증하는 단계에 있다. 수생태계에서 흔히 조사되는 플랑크톤의 군집구조 자료를 보면 하나의 조사대상 시료에서 출현하는 종의 수가 50 종정도에 이르며 각 개체의 종을 육안으로 확인하고 있으므로 종조성조사는 아직 자동화가 어렵다. 그러므로 플랑크톤 자료의 특성은 조사의 시료수(case)는 적고 측정항목(변수 variable)이 많은 특성을 가진다. 반면에 센서가 개발된 수질과 관련된 항목들은 자동측정설비가 확대되고 있어 변수는 적지만 장기간의 time series 들이 수집되고 있다. 녹조현상이 관심을 끌면서 여러 곳에 식물플랑크톤의 양을 측정하는 chlorophyll 센서가 설치되고 있는 것이 대표적인 사례이다. 그 외에 정량화되지 못하는 정성적 자료들도 수집되고 있으며 자료수집방법의 표준화도 미흡한 예가 많이 있고, 자료의 형태가 다양하여 데이터의 관리와 활용을 어렵게 한다. 환경부는 전국의 주요 하천 지점에서 정기적으로 수질을 측정하여 공개하고 있으며, 일부 지점에는 자동수질측정시설을 설치하여 측정의 빈도를 높이고 있다. 하천이나 호수에서 센서를 이용한 고빈도 모니터링은 그 동안 인지하지 못하였던 단기적 생태계 변화에 대해 새로운 정보를 제공하여 연구의 장르를 넓혀 가고 있다. 도시하천에서 산소를 측정한 사례를 보면 강우 시에 일시적으로 산소가 고갈되는 현상이 관찰되며, 부영양한 호수와 하천에서는 주야간 산소의 급격한 변동이 생태계 스트레스 요인으로 작용하고 있음을 알 수 있었다. 식물플랑크톤 센서의 연구에 의해 단기적인 변동이 크게 나타나고 있음이 새로이 밝혀지기도 하였다. 데이터의 수집과 활용도를 높이려는 노력도 이루어지고 있다. 과거에는 개인단위로 이루어지던 연구가 이제는 데이터를 수집하고 공유하는 플랫폼이 만들어 지면서 공동연구가 확대되고 있고, 국제적으로 지역을 초월하는 공동연구도 가능하게 되었다. 국제호수관측망학회(Global Lake Ecological Observatory Network, GLEON)이 그 사례이며 세계 여러 나라의 학자들이 참여하여 국제적으로 데이터를 공유하고 공동연구를 촉진하는 역할을 하고 있다. 생태계데이터의 증가는 생태학자들의 연구역량을 초과하는 데이터의 관리와 활용의 능력을 요구할 것이며 환경 생태 IT 분야의 융합연구의 필요성이 크게 대두되고 있다. 그간 데이터베이스의 구축에는 일부 성과가 있었으나 아직 수집된 데이터의 활용도를 높이고 타분야와의 협력연구 시너지를 확대하려는 노력은 부족하다. 이제는 데이터의 수집과 저장뿐 아니라 데이터의 활용도를 높일 수 있도록 학제적 협력연구를 촉진하는 off-line 모임도 확대할 때이다.

• Korean Journal of Optics and Photonics
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• v.30 no.4
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• pp.154-158
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• 2019

We have used a mid-IR (mid-infrared) continuous-wave (cw) optical parametric oscillator (OPO), developed previously and described in Ref. 12, to build a performance-evaluation setup for a mid-IR spectrometer. The used CW OPO had a wavelength tuning range of $ 2.5-3.6{\mu}m$ using a pump laser with a wavelength of 1064 nm and a fan-out MgO-doped periodically poled lithium niobate (MgO:PPLN) nonlinear crystal in a concentric cavity design. The OPO was combined with a near-IR integrating sphere and a Fourier-transform IR optical spectrum analyzer to build a performance-evaluation setup for mid-IR spectrometers. We applied this performance-evaluation setup to evaluating a mid-IR spectrometer developed domestically, and demonstrated the capability of evaluating the performance, such as spectral resolution, signal-to-noise ratio, spectral stray light, and so on, based on this setup.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.62-70
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• 2018

In this study, we synthesized Oligo Peptide (Lys-Val-Ala-Arg-Pro: KVARP) and peptide derivatives using Solid Phase Peptide Synthesis(SPPS). KVARP was commonly known to improve whitening of skin. We measured bio-activity of the synthesized compounds. The whitening effect was measured in tyrosinase inhibition and the result showed to be highly effective with 93% inhibition rate at $5000{\mu}g/m{\ell}$ of Geranic-KVARP, on the other hand the IC50 value was $68{\mu}g/m{\ell}$. The wrinkle-reducing effect was measured by elastase inhibition at a concentration of 63% at $400{\mu}g/m{\ell}$ of Salicylic-KVARP, and the IC50 value was $253{\mu}g/m{\ell}$. In the DPPH assay, Caffeic-KVARP showed more than 95% antioxidant activity at $400{\mu}g/m{\ell}$ with high concentration and IC50 value was $31{\mu}g/m{\ell}$. The anti-inflammatory effect of Nitric Oxide inhibition was 67% at $400{\mu}g/m{\ell}$ of Lipoic-KVARP. Therefore, the four types of KVARP derivative that were synthesized from various experiments has shown that it could have potential to be used to develop new medicines, cosmetics as well as in various industries.

• Journal of Adhesion and Interface
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• v.22 no.3
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• pp.85-90
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• 2021

Generally, the tensile strength of carbon fiber reinforced composite (CFRP) should be determined to produce this material. The tensile strength was performed based on ASTM D3039, and this test could cause the error by specimens and human. In this research, the CFRP tensile test was performed with different thickness of specimens and tap, adhesive for attaching tap, and pressure of jig to hold the specimens, while the test was performed based on ASTM D3039. The tensile stress and modulus exhibited differently with different specimen thicknesses, and the 1~1.5 mm thickness of the specimen was optimized. In the case of 0.28 MPa jig pressure, the slip or fracture at the clamping area of the specimen has not occurred, and specimens were fractured to the center section of the specimen. The adhesive to attach jig on specimen should be used to exhibit high adhesive stress. Experimental parameters could cause errors. It is expected to achieve an accurate tensile property evaluation of composite materials via improvements in adhesives, tabs, and jigs.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.273-288
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• 2021

We analyzed the spatio-temporal distribution characteristics of water quality and phytoplankton communities in the Isa Stream systems (ISS) from Sangsa Lake to Suncheon Bay. Sangsa Lake showed relatively oligotrophic and mesotrophic conditions, but the freshwater and mixed brackish water zones showed more severe eutrophication than Sangsa Lake and Suncheon Bay due to the influence of industrial waste such as livestock waste. In terms of the phytoplankton community, the number of phytoplankton species was higher in freshwater and mixed brackish water zones than in Sangsa Lake and Suncheon Bay, but the cell density and Chlorophyll-a concentrations (Chl-a) were relatively high in Sanga Lake and Suncheon Bay. In particular, the mesotrophic species Fragilaria crotonensis and Asterionella formosa showed different dominance in the surface and bottom layers, and the influence of A. formosa was significant in the freshwater and mixed brackish water zones in spring and summer. However, Skeletonema costatum-ls, a eutrophic indicator species, dominated in mixed brackish water zones to seawater in autumn and winter. Thus, the severe eutrophication and rapid environmental changes in the ISS could seriously damage the coastal ecosystem in Suncheon Bay. These ecosystem changes are threatening in terms of conservation and management of the UNESCO Suncheon Biosphere Reserve and Yeoja Bay including Suncheon Bay, which recorded the first Ramsar wetland in Korea. Therefore, further research is needed to establish an in-depth management plan.

• Journal of Digital Convergence
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• v.19 no.8
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• pp.101-111
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• 2021

Irregular workers, which have recently caused various socio-economic issues and conflicts, generally have low loyalty to the organization and job satisfaction due to anxiety about employment. As a way to improve this, this study attempted to analyze the effect of organizational communication satisfaction of irregular workers on job satisfaction and organizational commitment. Among the 7th Human Capital Companies panel survey data, irregular workers survey data were collected and analyzed using the structural equation model analysis. The results were as follows: First, it was analyzed that organizational communication recognized by irregular workers had a positive(+) effect on job satisfaction and organizational commitment. Second, it was analyzed that job satisfaction had a positive(+) effect on organizational commitment. Third, it was analyzed that job satisfaction plays a mediating role in the relationship between communication satisfaction and organizational commitment. This study is significant in that it expanded the research subject to irregular workers from the existing service industry-oriented research, and that it included more diverse industries. The results of this study suggest that mission and vision sharing and communication activation system are needed to improve organizational effectiveness of irregular workers.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.39 no.3
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• pp.15-21
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• 2021

This study studied the value of the spatial organization of the temple and the form of the garden located in the Seojang area in the southwestern regions of China. The value of the Lama temple was looked into by examining the relationship between Lamaism and Lama temple through the spatial organiz ation, building arrangement, and garden of temples that served as the center of history, culture, and politics of the time in the process of converging Buddhism introduced through China's central districts and India with folk beliefs in Seojang through the poor environment. To this end, the value of the space and garden of the Lama temple was derived through the representative Lama temples, Potala Temple, Norbulingka Temple, and Dazhao Temple. First, due to the unique environment in which ice caps and green areas coexist, the representative Lama temples in Seojang, Potala Temple, Norbulingka Temple, and Dazhao Temple, are widely distributed in the form of leaning against valleys and mountain ranges based on folk beliefs and Buddhism's Jatabuli(自他不二) and mandala. the target sites are largely divided into upper and lower spaces. Second, the target sites are largely divided into upper and lower spaces. Buildings for worship are located in the upper space, and spaces for practice and garden are located in the lower space. The garden existed in two main forms. Third, the garden existed in two main forms. Located in the center of the practice space, the garden had an ideal structure to plant bo tree to escape from the two false obsession and go to a world of truth that is with the Buddha behind the world through practice like Sakyamuni, and there was a garden around the temple where meditation and exchange took place. Evergreen coniferous forests are mainly planted in the forests.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.2
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• pp.73-77
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• 2021

Ga-doped ZnO thin films by RF magnetron sputtering process were synthesized according to the deposition conditions of O2 and Ar atmosphere gases, and rapid heat treatment (RTA) was performed at 600℃ in an N2 atmosphere. The thickness of the deposited ZnO : Ga thin film was measured, the crystal phase was investigated by XRD pattern analysis, and the microstructure of the thin film was observed by FE-SEM and AFM images. The intensity of the (002) plane of the X-ray diffraction pattern showed a significant difference depending on the deposition conditions of the thin films formed by O2 and Ar atmosphere gas types. In the case of a single thin f ilm doped with Ga under O2 conditions, a strong diffraction peak was observed. Under O2 and Ar conditions, in the case of a multilayer thin film with Ga doping, only a peak on the (002) plane with a somewhat weak intensity was shown. In the FE-SEM image, it was observed that the grain size of the surface of the thin film slightly increased as the thickness increased. In the case of a multilayer thin film with Ga doping under O2 and Ar atmosphere conditions, the specific resistance was 6.4 × 10-4 Ω·cm. In the case of a single thin film with Ga doping under O2 atmosphere conditions, the resistance of the thin film decreased. The resistance decreased as the thickness of the Ga-doped ZnO thin film increased to 2 ㎛, showing relatively a low specific resistance of 1.0 × 10-3 Ω·cm.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.6
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• pp.384-395
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• 2020

Breaking waves generated by wave shoaling in coastal areas have a close relationship with various physical phenomena in coastal regions, such as sediment transport, longshore currents, and shock wave pressure. Therefore, it is crucial to accurately predict breaker index such as breaking wave height and breaking depth, when designing coastal structures. Numerous scientific efforts have been made in the past by many researchers to identify and predict the breaking phenomenon. Representative studies on wave breaking provide many empirical formulas for the prediction of breaking index, mainly through hydraulic model experiments. However, the existing empirical formulas for breaking index determine the coefficients of the assumed equation through statistical analysis of data under the assumption of a specific equation. In this paper, we applied a representative linear-based supervised machine learning algorithms that show high predictive performance in various research fields related to regression or classification problems. Based on the used machine learning methods, a model for prediction of the breaking index is developed from previously published experimental data on the breaking wave, and a new linear equation for prediction of breaker index is presented from the trained model. The newly proposed breaker index formula showed similar predictive performance compared to the existing empirical formula, although it was a simple linear equation.