• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.5
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• pp.839-854
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• 2018

This study was performed to evaluate the performance of GFRP plate reinforced segments for TBM tunnel support. Recently, the SFRC segment has been applied to prevent local damage such as reduction of the amount of reinforcing bars of the segment, crack control and breakage. However, the steel fiber used in the SFRC segment has a problem of durability deterioration due to fiber corrosion. Compared with the RC segment, the maximum flexural load reduction of the SFRC segment hinders the broad application range of the TBM tunnel segment. Therefore, GFRP plate was considered as a stiffener for the maximum load increase of SFRC segment, and structural synthetic fiber without corrosive concern was used as a substitute for steel fiber. The flexural performance of the segment was evaluated by using the type of reinforcing fiber and GFRP plate thickness as the main parameters. As a result, the maximum load and the flexural toughness were increased by 21.78~23.03% and 0.5~7.96%, respectively, as compared with the segments reinforced with reinforcing fiber and GFRP plate of 3 mm thickness.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.70-78
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• 1991

Both long period of summer drought and unusual high water temperature in 1988 caused the harmfull effect to the aquacultural organisms in south coast of Korea. One of those was the mass mortality of arkshell seedlings in Jinhae Bay. The purpose of this study was to verify the effects of environmental factors on arkshell seedlings by investigating not only water quality and food organisms in culturing grounds, but also meteorological conditions. Water temperature in November was higher at $2.0^{\circ}C$ than mean water temperature and the concentration of total inorganic nitrogen and N/P ratio were $0.38{\mu}g-at/l,$ 0.98, respectively which indicated the exhaustion of nutrients, especially nitrogen in the study area. In analysis of phytoplankton population structure, species diversity index(H) , equitability-index(e), species richness $index(d_1)$ were low, but dominance $index({\delta}_2)$ was high at the value of 98.4 and dominant species was Nitzschia pungens. In conclusion, it seems that mass .mortality of arkshell seedlings in November was resulted from the metabolism disorder with poor food organism under the unstable marine environment.

• The Korean Journal of Mycology
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• v.48 no.1
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• pp.15-27
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• 2020

In screening for antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) KCCM 40510 and Bacillus cereus KCTC 3624, NNIBRFG5039 was isolated from the air in Sangju-si, Gyeongsangbuk-do. Based on a high sequence similarity of the internal transcribed spacer (ITS) region, NNIBRFG5039 was determined to be closely related to Penicillium rubefaciens CBS 139145. The optimal media, initial pH, and temperature for mycelial growth and antimicrobial activity of P. rubefaciens NNIBRFG5039 were determined as follows: potato dextrose broth (PDB), pH 6.5, and 30℃, respectively. Under the optimal culture conditions, maximum mycelial growth (12.4 g L^-1) and antibacterial activity (7.5 mm zone of inhibition against MRSA KCCM 40510, and 5.0 mm zone of inhibition against B. cereus KCTC 3624) were observed in a 5 L stirred-tank fermenter. We also isolated the antimicrobial compound from an ethyl acetate fraction, and its chemical structure was identified as (S)-6-hydroxymellein (1) by ESI-MS, ¹H-NMR, and ¹³C-NMR. Consequently, the extract from P. rubefaciens NNIBRFG5039 may be used in functional materials for antimicrobial-related applications.

• Journal of the Korea Institute of Building Construction
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• v.10 no.5
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• pp.113-119
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• 2010

Fire resistance and field tests for high-strength concrete(HSC) of 80MPa were carried out to evaluate whether or not it shows the same material properties even in the field condition of being mass-produced and supplied. As a result, it was found that fire resistant HSCs containing composite fiber(NY, PP) of 0.075% have great resistance to fire and spalling. In the field test, before the pumping air contents, slump flow, U-box, L-flow, compressive strength, gap of hydration temperature of interior and exterior of specimen and placing ratio per hour satisfied the required properties of HSC. However, after the pumping of HSC, as slump flow and L-flow were slightly less than required criterion, they need to be improved. In terms of hydration temperature of HSC, it was found to satisfy the related criterion. Packing ability as well as placing ratio per hour of HSC, which was about $44m^3$, show outstanding results. If slump flow of developed ternary HSC is improved after the pumping it can be useful for the construction of high-rise buildings.

• Journal of Science of Art and Design
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• v.9
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• pp.89-115
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• 2006

한국근대미술은 유화 도입기인 1910년대를 한국미술사의 중요한 시작점이다. 1910년경부터 형성되기 시작한 유화 도입배경과 그것이 당시 사회의 절실한 요청에 의한 것이었는지, 그렇다면 그것이 무엇인지 규명하는 것이 한국근대미술 초기를 알 수 있는 중요한 문제일 것이다. 일본근대 유화의 역사는 국수주의와 서구주의 물결이 반복하는 과정에서 점차 일본화된 소재의 등장과 일본정서에 부합하는 화풍을 만들어 나가게 되는 것이 1890년대부터 1910때까지의 일본근대 유화계의 상황이라고 할 수 있다. 이 시기를 다시 요약하면 외광파와 인상파가 절충된 양식에 일본의 메이지낭만주의에 부합하는 소재 즉 일본전통이라고 할 수 있는 풍경에 대한 애착 등이 전체 유화의 기류로 나타나는 시기라고 할 수 있다. 실제 새로운 문화의 하나였던 유화는 점차 세계의 다양한 미술사조 속에서 일본화다운 것으로 발전하는 모습을 보여준다. '구로다 세이키'(黑田淸輝) 이전에 이미 형성되었던 일본근대 유화양식과 구로다의 외광파 양식, 또 외광파가 일본 근대유화의 주류로 형성하게 되는 계기, 여기에 프랑스에서 직접 배워 온 작가들에 의한 인상파 도입 그리고 일본 '메이지낭만주의'(明治浪漫主義)의 등장으로 인한 사회 환경구조의 변화 속에서 양성된 그들의 절충양식의 초기유학생들에게 큰 영향을 미쳤다. 우리근대미술은 '민족적 자부심'과 '민족적 열등감'이 동시에 존재하는 사회적 배경논리에서 출발하지 않으면 안 된다. 즉 근대미술의 사상적 배경에는 민족 개량주의적 발상과 계몽주의적 문화 활동에 있었다고 할지라도 근본적으로는 미술자체를 근대사회 발전의 연장선 속에서 파악하지 못했고, 따라서 미술자체를 새로운 문명수입이라는 근대적 풍물 정도로만 파악했던 것이 어쩔 수 없는 근대미술의 한계라고 할 수 있다. 이 시기에 미술을 주목한 이유는 근대적 사회로 발전하기 위한 하나의 필수적인 요소로 미술자체를 파악하고 나아가, 식산흥업(殖産興業)의 수단으로 인식 했던 신지식층에 의해 시작되었다고 할 수 있다. 문명의 발달이 미술의 발달에서 연원한다는 '미술문명론' 같은 시각이 미술자체가 성격이나 창작의 방향과는 무관하게 어떤 미술이든 그것을 활성화시키는 것이 근대 즉 문명화된 세계로 나아갈 수 있다고 하는 관점에서 비롯된 것이라고 할 수 있다. 한국근대미술에 있어서 아카데미즘 역시 일본근대미술과 불가분의 관계가 있음을 부인할 수 없다. 초기유학생들은 그 당시 일본의 잡지나 화단에서 일어나는 여러 가지 시안들을 피상적으로 이해하는 정도였을 것으로 파악할 수 있다. 이러한 맥락에서 보면 한국근대미술에 있어서 초기유학생들의 작품과 그 이후 선전에서 입선하는 작품들은 일본아카데미즘의 영향 밑에 있다고 해야 할 것이다. 일본 근대 유화에서 형성된 외광파의 요소와 인상파 요소들이 일본 낭만주의로 표면화된 하나의 일본근대 유화의 형식 그대로가 한국아카데미즘의 성격을 결정하고 있다고 할 수 있다. 게다가 1922년에 시작된 선전은 심사위원 대부분이 동경미술학교 교수이면서 구로다의 제자이거나 동료였다는 것은 이러한 사실을 더욱 확고하게 뒷받침하고 있는 것이다. 초기유학생들이 남긴 작품들은 완전한 인상파에 대한 지식이나 깊은 자아의식을 가지고 제작된 것은 아니라, 일본 동경미술학교에서 가르치고 있었던 것들을 그대로 수용했다고 할 수 있다. 따라서 이들의 그림은 구로다의 외광파라고 부르는 것들의 영향보다는, 인상파를 보고 배웠던 동경미술학교 교수들의 영향을 더 많이 받았다고 할 수 있다. 그리고 이들의 영향은 그대로 한국 근대미술의 아카데미즘을 형성하는데 커다란 영향을 미치고 있음을 부인할 수 없다.

• International Journal of Highway Engineering
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• v.10 no.4
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• pp.9-18
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• 2008

Curling is caused by the difference in the temperature and humidity by the depth of the slab in Jointed Plain Concrete Pavement. Slab curvature shape and size change due to curling exert a profound influence on the internal stress and roughness of the pavement, affecting structural and functional performance of the pavement. Direct measurement of the slab curvature entails many problems. Many measuring instruments have to be installed at the early-stage of the pavement construction, and the behavior of the slab curvature needs to be measured accurately from the early-stage. Moreover, the cost and technical difficulty are very formidable to measure the slab curvature. This study develops a measurement method for slab curvature in jointed concrete pavement at any given time by applying Power Spectrum Density Analysis and Inverse Fast Fourier Transformation to the profile data, that can be easily obtained at the construction field site. The effectiveness of this developed method is verified by measuring the profile data of the test road of jointed concrete pavement at an inland central expressway by the hour and by examining the result of extracting the slab curvature shape from this profile data. Additionally, the profile data of CRCP(Continuously Reinforced Concrete Pavement) sections on the same expressway were obtained and analyzed at the same time. The validity of the method developed for the slab curvature shape extraction is verified by comparing the result from the analysis of the profile data of CRCP sections with that from the analysis of the prof1Ie data of jointed concrete pavement sections.

• Korean Journal of Remote Sensing
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• v.35 no.6_1
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• pp.999-1009
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• 2019

The importance of high-resolution sea ice maps of the Arctic Ocean is increasing due to the possibility of pioneering North Pole Routes and the necessity of precise climate prediction models. In this study,sea ice classification algorithms for two deep learning models were examined using Sentinel-1 A/B SAR data to generate high-resolution sea ice classification maps. Based on current ice charts, three classes (Open Water, First Year Ice, Multi Year Ice) of training data sets were generated by Arctic sea ice and remote sensing experts. Ten sea ice classification algorithms were generated by combing two deep learning models (i.e. Simple CNN and Resnet50) and five cases of input bands including incident angles and thermal noise corrected HV bands. For the ten algorithms, analyses were performed by comparing classification results with ground truth points. A confusion matrix and Cohen's kappa coefficient were produced for the case that showed best result. Furthermore, the classification result with the Maximum Likelihood Classifier that has been traditionally employed to classify sea ice. In conclusion, the Convolutional Neural Network case, which has two convolution layers and two max pooling layers, with HV and incident angle input bands shows classification accuracy of 96.66%, and Cohen's kappa coefficient of 0.9499. All deep learning cases shows better classification accuracy than the classification result of the Maximum Likelihood Classifier.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.4
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• pp.427-435
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• 1984

Alfalfa field was established to investigate seasonal changes of nodule activity and contents of carbohydrates, and nitrogen, and also to examine their relationships in alfalfa (Medicago sativa L.). Periodical sampling of alfalfa in cutting and uncutting plots was collected to measure growth of plants, development and activity of nodule, and content of carbohydrates and nitrogen in the third year following year of establishment. Nodule activity of alfalfa root appeared to early April, increased to a maximum in beginning of June (flowering stage), and then decreased and generally remained low from late-July to mid-August, and again increased from early September, and then decreased and generally remained low for the rest of growing season. After flowering, nodule weight tended to decrease slowly throughout the growing season. Until flowering stage, increase of dry weight was closely related with that of nodule activity. But after flowering the curve pattern of dry weight did not fit to that of nodule activity due to decrease of supply of assimilate to nodule, drought, and high temperature. Total nonstructural carbohydrates in roots were closely correlated with nodule weight and nodule activity. While, nitrogen contents in leaves were closely correlated with nodule weight and nodule activity. Also cutting on July prevented unnessesary losses of respiration during summer to provide rapid recovery of nodule activity.

• Applied Chemistry for Engineering
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• v.5 no.2
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• pp.345-356
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• 1994

Each of the three cationized compounds synthesized previously, poly(OMA-co-DAMA)[PODC], poly(DMA-co-DAMA)[PDDC] and poly(EMA-co-DAMA)[PEDC] was blended with waxes, emulsifiers and cationized fatty carbamide(ODTCC) synthesized in this study for the preparation of some durable softening water-repellenting agents, PODCW, PDDCW and PEDCW. The results of washability, tearing strength, crease recovery and contact angle of the cotton fabrics treated with PODCW, PDDCW and PEDCW with and without textile finishing resin, showed remarkable improvement of the physical properties. Rating of water repellency of cotton fabric treated with PODCW was 80, but those treated with PDDCW and PEDCW were not high enough to use in industry. Proper curing temperature of the synthesized water-repelleting agents was $140^{\circ}C$; proper using concentration was 3wt%; sodium acetate was the best catalyst for water-repellenting agents among the used, and proper concentration was 0.6wt%. From the results of reaction mechanism of cellulosic fiber with water-repellenting agent and washability of the fibers treated with water-repellenting agents the prepared water-repellenting agent proved to be durable. Surface structures of cotton fabrics treated with water-repellenting agent were investigated by SEM.

• Journal of the Korean Chemical Society
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• v.46 no.4
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• pp.336-345
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• 2002

In this study, we have screened $Eu^{3+}$- and $Tb^{3+}$-activated candidate phosphors for PDP in the sys-tems of CaO-Gd$_2$O$_3$-Al$_2$O$_3$ by combinatorial chemistry and investigated the synthetic temperature, optimum com-position and luminescent properties about the candidate phosphors. To construct the emission intensity library by VUV PL, we have synthesized 210 different compositional samples using a polymerized-complex method. Good luminescent samples were identified by X-ray diffraction method. $Ca_$\alpha$$G$d_{0.95-$\alpha$-$\beta$}Al_$\beta$O_$\delta$$ : Eu(0.02< $\alpha$+$\beta$ <0.04) phos-phors screened as a red phosphor have good color purity than commercial phosphor. In the candidate phosphors of CaGdAl$_3O_7$ : Tb, Ca$Al_{12}O_{19}$ : Tb, Gd$_4$Al$_2O_9$ : Tb, and Gd$_3Al_5O_{12}$ : Tb CaGdAl$_3O_7$ : Tb, and Ca$Al_{12}O_{19}$ : Tb have shorter decay time than commercial phosphor.