• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.6
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• pp.154-160
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• 2021

Recently, there have been increasing construction works carried out in urban centers, which are inducing frequent artificial vibration in the vicinity of existing structures due to such construction works. moreover, in case of industrial estates, vibration is induced due to operation of machines in the surrounding areas, thereby causing problems. meanwhile, in case of ordinary concrete that compose structure has low level of damping capability for vibration. accordingly, there are difficulties in blocking a wide range of vibrations delivered to the structures from outside including not only vibrations generated in the structures themselves but also ground vibration. recently, numerous studies are being carried out actively on high-damping system that markedly enhanced the damping performances of structures by utilizing polymer concrete in order to block the vibrations delivered to the structures through ground. therefore, this study compared the performances of polymer concrete with those of ordinary concrete, polyurethane pad and foamed rubber pad in order to review its performances in reducing ground vibration. for this purpose, review of FRF and vibration acceleration as dynamic characteristics was made. after comparative verification on the dynamic characteristics is made when polymer concrete and other aforementioned materials are applied to underground structures, the possibility of application of polymer concrete to structures is reviewed.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.2
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• pp.121-127
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• 2024

In this study, the applicability of replacing DG(Desulfurized Gypsum) from oil refinery with CCCMs(Carbon dioxide Conversion Capture Materials) as an ALC(Auto-claved LIghtweight Concrete) raw material was examined, and basic properties of ALC was measured. The main chemical components of DG and CCCMs were CaO and SO₃, and an increase in LOI(Loss of ignition) due to mineral carbonation reaction was verified. The crystalline phases of CCCMs were CaCO₃, CaSO₄, Ca(OH)₂, and CaSO₄·2H₂O. When DG, a raw material for ALC production, was replaced with CCCMs, foaming height, pore shape, absolute dry gravity, and compressive strength results measured similar for all binders. In addition, the formation of tobermorite which is main crystalline phase of ALC was shown for all specimens in microstructural analysis.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.2
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• pp.117-125
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• 2000

The waveform and spectrum analysis of Tursiops truncatus(bottlenose dolphin) sonar signals were carried out on the basis of data collected during the dolphin show at the aquarium of Cheju Pacificland from October 1998 to February 1999. When greeting to audience, the pulse width, peak frequency and spectrum level from the five dolphins'sonar signals were 3.0ms, 4.54kHz and 125.6dB, respectively. At the time of warm-up just before the show, their figures were 5.0㎳, 5.24kHz and 127.0dB, respectively. During the performance of dolphins, with singing, peak frequency ranged 3.28∼5.78kHz and spectrum level ranged 137.0∼142.0dB. With playing ring, pulse width, peak frequency and spectrum level were 7.0㎳, 2.54kHz and 135.9dB, and when playing the ball, the values were 9.0㎳, 2.78kHz and 135.2dB, respectively. The values determined from the five dolphins during jump-up out of water were : pulse width 2.0㎳, peak frequency 4.50kHz and spectrum level 126.8dB. When they responded to trainer's instructions, the values were 2.25㎳, 248kHz and 148.7dB, respectively, and greeting to audience, the peak frequency and spectrum level were 5.84kHz and 122.5dB. During swimming under water, peak frequency and spectrum level were determined to be 10.10kHz and 126.8dB. It was found that there exited close consistencies in pulse width, frequency distribution and spectrum level between whistle sounds and dolphin's sonar signals. Accordingly, the dolphins can be easily trained by using whistle sound based on the results obtained from the waveform and spectrum of the dolphin's sonar signals.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.175-185
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• 2000

This paper described on a basic study to organize fishing vessel control system in order to control efficiently fishing vessel in Korean offshore. It was digitalized ARPA image on the fishing processing of a fleet of purse seiner in conducting fishing operation at Cheju offshore in Korea as a digital camera and then simulated by used VTMS. Futhermore, it was investigated on the application of FVTMS which can control efficiently fishing vessels in fishing ground. The results obtained were as follows ; (1) It was taken 16 minutes and 35 minutes to casting and hauling net in fishing processing respectively. The length of rope pulled by scout boat was 200m, tactical diameter in casting net was 340.8m, turning speed was 6kts as well. (2) The processing of casting and hauling net was moved to SW, NE as results of simulation when the current direction and speed set into NE, 2kts and SW, 2kts respectively. Such as these results suggest that can predict to control the fishing vessel previously with information of fishing ground, fishery and ship's maneuvering, etc. (3) The control range of VTMS radar used in simulation was about 16 miles. Although converting from a radar of the control vessel to another one, it was continuously acquired for the vector and the target data. The optimum control position could be determined by measuring and analyzing to distance and direction between the control vessel and the fleet of fishing vessel. (4) The FVTMS(fishing vessel traffic management services) model was suggested that fishing vessels received fishing conditions and safety navigation information can operate safely and efficiently.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.189-194
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• 2001

It is possible to use hairy vetch as green manure for corn not only in corn single cropping but also in double cropping system of corn and fall oats. Fall oats and hairy vetch were mixed-sown after corn harvest and harvested as forage in the early of November, and then hairy vetch stubble was over-wintered and incorporated into soil at corn planting as green manure without N fertilizer (FO+HV-GM). Other treatments were fall oats without N fertilizer on corn (FO-0N) and with N fertilizer 200kg/ha on corn (FO-200N), hairy vetch green manure without N fertilizer on corn (HV-GM), and fell winter follow without N fertilizer on corn (WF-0N). Soil nitrate content, corn growth and nitrogen uptakes, and yield of corn were measured and compared during 2-year experimental seasons. Dry matter and N amount of hairy vetch at the plot of FO+HV-GM were 60% less than those at the plot of HV-GM. The N effect of hairy vetch green manure on corn at the plot of HV-GM was similar to that at FO-200N plot for two years. Soil nitrate at the plot of FO+HV-GM was below the half of those at plots of HV-GM and FO-200N at 6-leaf stage of corn. N uptake of corn at the plot of FO+HV-GM at silking stage was 30% less than those at plot of HV-GM and FO-200N. However, soil nitrate at 6-leaf stage of corn and the amount of nitrogen uptake of corn at silking stage increased two times and 30-40 kg/ha, respectively, compared with those at the plot of FO-0N. Corn yield at FO+HV-GM decreased about 2 ton/ha due to the decrease of corn grain weight in the first year compared with plot of HV-GM and FO-200N, but its difference was not shown in succeeding second year. Corn N uptake at FO+HV-GM decreased 60 kg/ha and 20 kg/ha in 1999 and 2000, compared with plot of HV-GM and FO-200N, respectively, but increased 30kg/ha and 45kg/ha compared with the plot of FO-0N in 1999, 2000, respectively. Therefore, it is estimated that hairy vetch green manure in fall oats-corn double cropping system can reduce nitrogen chemical fertilizer on corn as much as 50-100 kg/ha although its N effect is much lower than the N effect of hairy vetch green manure in corn single cropping of which N effect is over 200 kg/ha.

• Journal of the Korean Wood Science and Technology
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• v.46 no.1
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• pp.73-84
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• 2018

Recently, the importance of flame retardation treatment technology has been emphasized due to the increase in urban fire accidents and fire damage incidents caused by building exterior materials. Particularly, in the utilization of wood-based building materials, the flame retarding treatment technology is more importantly evaluated. An Intumescent system is one of the non-halogen flame retardant treatment technologies and is a system that realizes flame retardancy through foaming and carbonization layer formation. To apply the Intumescent system, composite material was prepared by using Ethylene vinyl acetate (EVA) as a matrix. To enhance the flame retardant properties of the Intumescent system, a nano-clay was applied together. Composite materials with Intumescent system and nano - clay technology were processed into sheet - like test specimens, and then a new structure of cross laminated timber with improved flame retardant properties was fabricated. In the evaluation of combustion characteristics of composite materials using Intumescent system, it was confirmed that the maximum heat emission was reduced efficiently. Depending on the structure attached to the surface, the CLT had two stages of combustion. Also, it was confirmed that the maximum calorific value decreased significantly during the deep burning process. These characteristics are expected to have a delayed combustion diffusion effect in the combustion process of CLT. In order to improve the performance, the flame retardation treatment technique for the surface veneer and the optimization technique of the application of the composite material are required. It is expected that it will be possible to develop a CLT structure with improved fire characteristics.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.283-290
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• 1982

Sardine and mackerel so called dark muscled fish have been underutilized due to the disadvantages in bloody meat color, high content of fat, and postmortem instability of protein. Recent efforts were made to overcome these defects and develope new types of product such as texturized protein concentrates and dark muscle eliminated minced fish. Approach of this study is based on the rapid dehydration of foamed fish-starch paste by dielectric heating. In process comminuted sardine meat was washed more than three times by soaking and decanting in chilled water and finally centrifuged. The meat was ground in a stone mortar added Ivith adequate amounts of salt, foaming agent, and other ingredients for aid to elasticity and foam stability. The ground meat paste was extruded in finger shape and heated in a microwave oven to give foamed, expanded, and porous solid structure by dehydration. Dielectric onstant $(\varepsilon')$ and dielect.ic loss $(\varepsilon")$ values of sardine meat paste were influenced by wavelength and moisture level. Those values at 100 KHz and 15 MHz were ranged 2.25-9.86; 2.22-4,18 for E' and 0.24-19.24; 0.16-1.20 for E", respectively, at the moisture levels of $4.2-13.8\%$. For a formula for fish-starch paste preparation, addition of $20-30\%$ starch (potato starch) to the weight of fish meat, $2-4\%$ salt, and $5-10\%$ soybean protein was adequate to yield 4-5 folds of expansion in volume when heated. Addition of e99 yolk was of benefit to micronize foam size and better crispness. In order to provide better foaming and dehydration, addition of $0.2-0.5\%$sodium bicarbonate, foaming agent, was proper to result in foam size of 0.5-0.7 mm and foam density of $200-400\;/cm^2$ which gave a good crispness. Heating time was depended upon the moisture level of fish-starch paste. For a finger shaped paste (1.0cm. $D\times10cm.L$) heating for 150-200 sec. in a microwave oven (700W. 2.45GHz) was sufficient to generate foams, expand, and solidify the porous structure of fish-starch paste. When the moisture content was above $55\%$ browning and scorching was deepened due to over-expansion and over-heating whereas the crispness was hardened by insufficient expansion at lower moisture content. In quality evaluation of the product, chemical composition of $30\%$ starch and $3\%$ salt added product was moisture $8.8\%$, lipid $2.4\%$, carbohydrate $46.7\%$, protein $36.1\%$, and ash $6.0\%$. Eleven membered panel test evaluated that fish-starch paste was acceptable in color, crisp-ness, taste, except a trace of fishy odour which could be masked by the addition of spice extracts.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2012.05a
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• pp.10-10
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• 2012

독일의 와인 생산지는 라인 강과 그의 지류를 따라 대개 서남쪽에 산재해 있다. 독일은 102,000 헥타르(2005년, 전 세계 포도밭의 1.3%)의 포도밭을 가지고 있으며, 매년 약 915만 3천 헥토리터(2005년, 전 세계 생산량의 3.24%)의 와인을 생산하고 있다. 이는 독일이 포도 재배면적으로는 세계 13번째 국가이며, 와인 생산량으로는 세계 8위를 나타내는 수치이다. 독일은 원래 화이트와인의 나라였으나, 레드와인의 생산이 1990년대와 2000년대에 급속히 증가하였다. 현재(2011년) 독일 포도밭의 64%가 화이트와인을 위해 경작되고 있으며, 36%가 레드와인을 위해 경작되고 있다. 화이트와인을 위한 주요품종이 리슬링(Riesling, 22%), 레드와인을 위한 주요품종은 쉬페트부르군더(Sp$\ddot{a}$tburgunder, Pinot Noir, 11.5%)로 알려져 있다. 독일은 다양한 형태의 와인을 생산한다. 드라이(dry), 세미스위트(semi-sweet)와 스위트한 화이트와인들(sweet white wines), 로제와인, 레드와인과 발포성 와인인 젝트(Sekt, 독일형 샴페인)이다. 독일 포도밭의 위치가 북쪽이므로, 독일은 유럽의 다른 나라와는 전혀 다른 다수의 훌륭한 품질의 와인을 생산한다. 오늘날 독일의 포도재배는 1세기에서 4세기쯤의 고대 로마시대부터 시작된 것으로 알려져 있다. 카롤루스 대제(Carolus Magnus, 747/748-814)의 시대 전에 독일의 포도재배는 비록 독점적이지는 않았으나 라인의 서부지역에서 주로 경작되었다. 카롤루스 대제는 포도재배를 라인가우에 보급한 것으로 추측되고 있다. 1787년에 아우스레제(Auslese)로 시작한 수확된 성숙도에 기반을 둔 와인의 후속 분류는 품질보증 고급와인 체계의 초석을 놓았다. 대부분의 현재 독일 와인법은 1971년에 도입되었으며, 그 이후 사용되어온 바와 같이 품질보증 고급와인의 이름이 정의되었다. 독일와인 지역은 세계에서 가장 북쪽인 북위 $50^{\circ}$도 부근에 위치한다. 북쪽의 기후이기 때문에 적합한 포도 품종에 대한 연구가 되어왔으며, 가이젠하임 포도 육종 연구소에서 뮐러-투르가우와 같은 많은 교배종이 개발되어 왔다. 최근에 지역 및 국제 수요가 높은 품질의 와인을 요구함으로서 리슬링의 재배가 증가해 왔다. 와인은 모두 자주 산맥으로 보호된 주로 라인 강과 그 지류인 강 주변에서 생산된다. 강들은 온도를 조절하는 충분한 미기후 효과를 갖는다. 토양은 태양의 열을 흡수해서 그것을 밤에 보존하는 점판암이다. 독일 와인산업은 다수의 작은 포도밭 소유자로 이루어져 있다. 1989/90년에 서부독일에 76,683개의 크고 작은 기업이 있었으나, 1999년에는 68,598로 줄어들었으며, 2010년도의 조사에 의하면 48,009개의 기업이 조업 중인 것으로 나타났다. 그들 자신의 와인을 팔지 않거나 상업화할 수 없는 더 작은 포도 재배자는 여러 가지 선택이 가능하다. 즉 포도를 팔거나, 와인-생산 조합의 기본 와인으로서 그것을 사용하는 와인제조 회사에게 대량으로 와인을 판다. 정말로 좋은 장소에 포도밭을 가진 사람들도 포도밭을 전체적으로 경작하기를 원하는 대량 생산자들에게 빌려주는 선택을 할 수 있다. 2010년에 각각 5ha 이상을 지닌 5,974개의 포도밭 소유자가 독일 전 포도밭 면적의 70.3%를 소유하며, 생업 와인생산자와 기업이 여기에 속한다. 그러나 그들 자신의 포도밭을 지닌 진정으로 큰 와인 양조장은 독일에서는 희귀하다. 2007년의 고에 묘 와인가이드(Gault & Millau Weinguide)에 의한 독일에서 가장 좋은 것으로 생각되는 10개의 와인 양조장 중에 10개가 10.2-19ha의 포도밭, 하나(Weingut Robert Weil, 산토리 소유)가 75ha의 포도밭을 소유하였다. 이것은 대부분의 높은 순위의 독일 와인 양조장 각각 매년 약 100,000병의 와인을 생산한다는 것을 의미한다. 가장 큰 포도밭 소유자는 헤센의 주 와인 양조장(Hessische Staatsweing$\ddot{u}$ter)으로 헤센의 연방주에 의한 소유이며, 200ha의 포도밭을 지니고, 3개의 별도 와인 양조장에서 제조된다. 가장 큰 개인이 소유한 와인 양조장은 팔츠에 있는 85.5ha를 지닌 독토르 뷔르클린-볼프(Weingut Dr. B$\ddot{u}$rklin-Wolf)이다. 2009년도의 독일에서 총 와인 생산량은 910만 헥토리터였으며, 그중에 206만 8천 헥토리터를 수출하였다. 그러나 그해에 총 수입와인 양은 1,266만2천 헥토리터였다.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.388-395
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• 2016

This paper explores the photocatalytic sensitivity of cement mortar incorporated with recycled $TiO_2$ from waste water sludge. Basically, $TiO_2$ cluster sank down slowly to the bottom of cement mortar specimen before setting and hardening process. This leads the mismatch of $TiO_2$ concentration on the top and the bottom faces of a specimen. This poorly dispersed $TiO_2$-cement mortar naturally exhibits poor NOx removal efficiency especially on the top of cementitious structure. In architectural engineering application such as building or housing structures, one can simply filp over from the bottom so that more $TiO_2$ concentrated surface can be placed outward into the air. However, in highway pavement case, this could not be applicable due to in-situ installation of concrete pavement. Hence, the dispersion of $TiO_2$ cluster inside the cementitous material is getting important issue onto road construction application. To elaborate this issue, according to our results, silica fume, high-ranged water reducer, viscosity agent, blast furnace slag were not enhanced much of dispersion characteristics of $TiO_2$ cluster. The combination of foaming agent and accelerator of hardening with viscosity agent and small grain size of fine aggregate may help the dispersion of $TiO_2$ inside cementitious materials. Even though the enhanced dispersion were applied to the specimen, NOx removal efficiency doest not change much for the top surface of the specimen. This concurrently affected by the presence of tiny air voids and the dispersion of $TiO_2$ in that these voids could easily adsorbed NOx gas with the aid of large surface area.

• Resources Recycling
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• v.9 no.6
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• pp.36-44
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• 2000

Fly ash was composed of the unburned carbon and mineral particles. The former was able to attach on the bubbles, while the latter was not. Therefore, it was possible to separate the unburned carbon and the mineral from fly ash using the froth flotation process. This study was carried out to evaluate the separation efficiency as a function of the ny ash particle properties in the column flotation. Separation efficiency was analyzed for various size fraction of -38 fm,38~125 fm and 1125 W, and for various fly ash samples containing 7, 11, and 20 wt% unburned carbon. For the size fractions of -38 fm containing 7 wt% unburned carbon, separation efficiency was 86ft, whereas separation efficiency was found to be 74% for the size fraction of +125$\mu\textrm{m}$ containing 20 wt% unburned carbon. The results indicated that separation efficiency increased with the decrease in the particle size and the unburned carbon content of the fly ash.