This study was conducted to find out the effects of over seeding using new grass varieties orchardgrass ‘Kordione’ and ‘Onnuri’, and tall fescue ‘Greenmaster’ on botanical composition and dry matter productivity from 2013 to 2016 in low productivity hilly pasture, middle area of Korea. There were used 3 grass seed mixture types made of different compositions and amounts {T1: control - no over seeding, T2: tall fescue (TF) ‘Greenmaster’ 18 kg ha-1, orchardgrass (OG) ‘Kordione’ 9 kg ha-1, Perennial ryegrass (PRG) ‘Linn’ 5 kg ha-1, and Kentucky bluegrass (KBG) ‘Kenblue’ 2 kg ha-1, T3: TF ‘Greenmaster’ 9 kg ha-1, OG ‘Kordione’ 18 kg ha-1, PRG ‘Linn’ 5 kg ha-1, and KBG ‘ Kenblue’ 2 kg ha-1, T4: TF ‘Greenmaster’ 9 kg ha-1, OG ‘Onnuri’ 18 kg ha-1, PRG ‘Linn’ 5 kg ha-1, and KBG ‘Kenblue’ 2 kg ha-1}. In the botanical composition of grassland, T1 nearly remained constant in other seasons while ratio of weeds were increased in summer season. T2 was better than control (T1) in portion of grass ratio, which has increased by 80%. In the early time of establishment, the portions of OG were increased in T2, but TF rate was increased after 3 years later when grass was established. T3 and T4 showed a very similar patterns, grass ratio had increased by 80% and the portion of KBG had increased as time passed. T2 (129,763 kg ha-1) was showed the highest dry matter yield than other treatments (T1: 6,756 kg ha-1, T3: 9641, and T4: 10,738) in 2016.

Harmonic structure materials are materials with a core–shell structure having a shell with a small grain size and a core with a relatively large grain size. They are in the spotlight because their mechanical properties reportedly feature strength similar to that of a sintered powder with a fine grain size and elongation similar to that of a sintered powder with a coarse grain size at the same time. In this study, the tensile properties, microstructure, and stretchflangeability of harmonic structure SUS304L made using powder metallurgy are investigated to check its suitability for automotive applications. The harmonic powders are made by mechanical milling and sintered using a spark plasma sintering method at 1173 K and a pressure of 50 MPa in a cylindrical die. The sintered powders of SUS304L having harmonic structure (harmonic SUS304L) exhibit excellent tensile properties compared with sintered powders of SUS304L having homogeneous microstructure. In addition, the harmonic SUS304L has excellent stretch-flangeability compared with commercial advanced high-strength steels (AHSSs) at a similar strength grade. Thus, the harmonic SUS304L is more suitable for automotive applications than conventional AHSSs because it exhibits both excellent tensile properties and stretch-flangeability.

In recent years, the number of earthquakes has increased worldwide. There has been an extreme increase on the Korea Peninsula, which is considered a safety zone for earthquakes. In particular, in the event of earthquakes, most structures on the Korea Peninsula are severely damaged, because most are not designed to withstand them. Damage to and destruction of civil structures, such as bridges, nuclear facilities, and dams, is worse than that of other structures. It is necessary to evaluate and predict the extent of damage by earthquake magnitude, as the magnitude of earthquakes is increasing as well as the frequency. A major feature of the occurrence of earthquakes is uncertainty. For this reason, it is necessary to adopt a stochastic approach, and studies using this approach are increasing. However, although there have been several studies on bridges and nuclear facilities, there have been few studies on probabilistic seismic risk evaluation for multi-functional weirs. Thus, this study presents 3D multi-functional weirs and performs a time history analysis by using LS-DYNA, a general structure analysis program. Probabilistic seismic fragility assessment is conducted by Monte Carlo simulation.

최근 지구온난화로 인한 이상기상 현상이 가속화되면서 전국적으로 댕구알버섯의 발생이 증가추세이다. 댕구알버섯은 말불버섯목 말불버섯과에 속하며 대나무 밭, 야산 등 땅 위 풀밭에 발생하는 버섯으로 지름 이 20~45cm로 크기가 큰 버섯으로 알려져 있다. 한국, 일본, 중국 등 전세계적으로 분포하며 어린 버섯은 식용한다. 또한 지혈, 해독 작용이 있으며 기침, 인후염, 편도선염 등 항염제로도 활용되고 있다고 알려져 있다. 그러나 국내 자원에 대한 댕구알버섯의 특성이나 성분에 대한 연구보고는 없다. 따라서 본 연구에서는 국내 야생 댕구알버섯에 대한 기초자료로 활용하고자 2015년~2016년 전남지역에서 발생한 댕구알버섯을 채집하여 자실체의 특성을 조사하였고 영양성분을 분석하였다. 본 조사에 사용된 댕구알버섯은 야산 주변의 감나무 밭, 야산의 산길, 대나무 밭 등 주로 야산 근처에서 발견되었다. 발생시기는 2015년 7월 중순 나주, 2016년 7월 상순 해남, 9월 중순 나주, 10월 중순 함평 등 여름에서 가을사이에 장마철 또는 태풍이 지난 후에 공중습도가 매우 높을 때 발생된 것으로 조사되었다. 발생양상은 하룻밤사이에 발견당시 크기로 자라는 것으로 추정할 수 있었고 냉장고에 보관시 어린자실체는 며칠사이에 갈색을 띠면서 물로 내려앉아 소멸하였고 노화가 진행된 자실체는 구형의 모형을 유지하면서 그대로 건조되는 경향이었다. 자실체의 주요특성으로 자실체색은 흰색이었고 형태는 공모양이었으며 두 개의 자실체가 붙어진 모양 즉 타원형 모양 이었다. 크기는 직경이 12.3~28cm 사이에 분포하였고 무게는 476g 정도였다. 포자는 갈색을 띄었고 0.005㎜ 로 원형이며 표면에 돌기가 있었다. 수집한 댕구알버섯의 영양성분 함량을 분석한 결과 수분 89.37%, 회분 0.74%, 조단백질 6.39%, 조지방 0.39% 였으며 탄수화물은 3.11%로 나타났다. 식이섬유 함량은 2.83%로 나타났고 DPPH항산화활성은 0.874㎎/g Vit eq.이었다. 특이한 점은 일반성분 가운데 조단백질 함량이 다른 버섯에 비해 월등이 많은 것으로 분석되었으며 향후 생리활성 물질분석 등이 요구된다.

Torsional constants of both rectangular cross section and circular cross section are induced by exact solution, and was easy to calculate since of simple shape. However, it is very difficult to calculate the torsional constant of both an arbitrary cross-section and a composite cross-section. In this study, a finite element formulation was proposed as a method to calculate the torsional constant of both an arbitrary cross-section and a composite cross-section. From the numerical study, numerical results was compared with exact solution.

In this study, finite element analysis of korean precast concrete panels was performed and 3D infinite element modeling was used. Infinite elements can be formulated in time domain and nonlinear behavior analysis is possible. Based on the numerical results, the performance of the packing layer of korean precast concrete panels was examined.

본 연구는 영양부추의 미생물학적 안전성을 확보하기 위하여 이산화염소와 차아염소산나트륨을 이용하여 미생물의 저감효과를 분석하고, 최적의 영양부추와 소독제의 비율을 결정하기 위하여 수행하였다. 이를 위하여 영양부추에 E. coli, Salmonella spp., S. aureus, B. cereus을 7.0 log CFU/g 정도로 접종 한 후 이산화염소는 3, 5, 10, 25, 100 ppm 차아염소산나트륨은 100, 150, 200 ppm에서 5, 10, 30, 60분간 처리하였으며, 또한 유기물이 이산화염소와 차아염소산나트륨의 효과에 미치는 영향을 분석하기 위해 영양부추와 소독제를 1 : 2, 1 : 4, 1 : 9, 1 : 19 비율로 처리 하여 소독제의 효과를 분석하였다. 그 결과, 소독제의 농도에 따른 저감효과는 차아염소산나트륨 150 ppm, 이산화 염소 50 ppm으로 30분간 처리시 일반세균수는 2.0 log CFU/ g 정도 감소효과를 나타내었으며, 식중독세균은 차아염소 산나트륨 100 ppm, 이산화염소 3 ppm에서 약 2.0 log CFU/g 정도 감소효과를 보였다. 한편, 이산화염소의 경우 50 ppm 으로 30분간 영양부추를 처리할 경우 탈색 등 상품성이 저하되어 현장 적용이 어렵다고 판단되었다. 또한 영양부 추와 소독제 처리 비율에 따른 미생물 저감효과는 일반세 균의 경우 1 : 4에 비하여 1 : 9에서 유의적으로 높은 저감 효과를 보였다(p < 0.05). 확립된 기술을 영양부추 생산농 장에 적용한 결과 일반세균수의 경우 2.7 log CFU/g, 대장 균군의 경우 4.0 log CFU/g의 감소효과를 보였다. 따라서 영양부추를 세척이후 차아염소산나트륨 150 ppm에서 1 : 9 정도의 비율로 30분간 침지하면 미생물 안전성을 향상시 킬 수 있으며, 최종 소비자에게 보다 안전한 부추의 공급이 가능할 것으로 판단된다.

The number of earthquakes is increased recently. A electrical equipment is very important in all electric system because it can make a serious problems in such as nuclear power plants like a black out. So, seismic safety design of electrical equipment is necessary to keep to use the convenience of electronics. In this study, threshold values of electronic equipment was founded out from the numerical results by using seismic load.

A behavior of FRP(Fiber Reinforced Polymer) panel in a steel frame structure was evaluated through the finite element analysis in this study. In order to numerical analysis, a experimental test results was used to develop a three dimensional finite element model of steel frame specimen. Numerical results of the steel frame specimen was well predicted the experimental behavior of steel frame specimen. Based on the developed three dimensional finite element model of steel frame specimen, the behavior of FRP panel in the steel frame specimen was evaluated. From the numerical analysis results, strength of the steel frame specimen with FRP panel was governed by FRP panel. Also, diagonal compression behavior governed the FRP panel in the steel frame specimen in the numerical analysis results.

For economic evaluation of integrated operation to sewage facilities, benefit-cost analysis was performed to watershed sewage works project in 7 watershed areas, 156 facilities. In this study, the cost before and after integrated operation was compared and benefits are calculated from the reduction of operators, increasement treated pollution loads, reduction cost through operation convenience, reduction water consumption through effluent reuse, and improvement of life benefit. The result showed that cost was 8,500million won and benefit was 16,747million won, so benefit was 49% higher than cost. B/C analysis result showed that B/C ratio was 1.97 and it is similar to other researches. The benefits of integrated operation included convenience of data management, increase of emergency response, decrease of complains with sewage which was not reflected numerically, so the benefits of integrated operation were expected much greater than this result.

Transparent organic-inorganic hybrid hard coating films were prepared by the addition of SiO2 or ZrO2, as an inorganic filler to improve the hardness property, filler was highly dispersed in the acrylic resin. To improve the compatibility in the acrylic resin, SiO2 or ZrO2 is surface-modified using various silanes with variation of the modification time and silane content. Depending on the content and kind of the modified inorganic oxide, transparent modified inorganic sols were formulated in acryl resin. Then, the sols were bar coated and cured on PET films to investigate the optical and mechanical properties. The optimized film, which has a modified ZrO2 content of 4 wt% markedly improved in terms of the hardness, haze, and transparency as compared to neat acrylate resin and acrylate resin containing modified SiO2 content of 8 wt%. Meanwhile, the low transparency and high haze of these films slowly appeared at SiO2 content above 10 wt% and ZrO2 content of 5 wt%, but the hardness values were maintained at 2H and 3H, respectively, in comparison with the HB of neat acrylate resin.

본 연구는 수출 딸기 중 병원성 E. coli와 Salmonella spp.를 제어하기 위하여 이산화염소 가스 농도, 상대습도, 시간에 따른 이산화염소 가스의 미생물 저감효과를 조사하였다. 병원성 E. coli, salmonella spp.를 접종한 딸기에 이산화염소 가스 농도(10, 20, 30, 40, 50 ppmv), 상대습도(50, 70, 90%), 처리시간(0, 5, 10, 20, 30분)에 대한 삼요인 실험을 하였다. 그 결과, 각 처리 조건 간의 상호작용이 나타났으며 미생물 저감효과는 상대습도가 가장 높은 조건인 90%에서 이산화염소 가스 농도와 처리시간의 값이 증가할수록 높아지는 경향이 있었다. 상대습도 90%, 이산화염소 가스 농도 50 ppmv에서 처리시간에 따른 미생물 저감화 효과는 5분 동안 처리하였을 때 병원성 E. coli와 Salmonella spp.이 각각 0.5, 0.7 log CFU/g 정도 감소하였으나 20분간 처리하였을 때는 각각 2.07과 2.28 log CFU/g 정도 감소하였다. 따라서 본 연구는 수출 딸기 중병원성 E. coli와 Salmonella spp.를 제어하기 위한 최적의 이산화염소가스 처리 조건을 확립한 결과로서 수출 딸기의 미생물 안전성 향상에 기여할 수 있으리라 사료된다.

This study evaluated the effect 3 types of conditioning (Untreated, Impeller, Roller) and the number of times for tedding (rake-teder) performed in one day on the drying rate of tall fescure hay. The experiment was performed at The forage site of Cheonan-si seongwhan-eup National Institute of Animal Sciencee. It took 3 days to make tall fescue hay. The Impeller and Roller conditioning types shortened the haymaking period by 1 day compared to untreated hay. Impeller and roller samples had less than 20% of water content by the 23rd-day at 13 o’clock. Tedding frequency failed to affect haymaking. There was no correlation between the three types of conditioning or tedding frequency and acid digestible fiber (ADF), neutral detergent fiber (NDF), total digestible nutrients (TDF), crude protein (CP), or relative feed value (RFV) in tall fescue hay. CP was 12.5~12.9% for the three types of conditioner with 1 or 2 times of tedding a day, Threrfore, conditioner types and gedding frequency had no significant effect on CP.

This study was conducted to determine the effect of rainfall after cutting on nutritive value of Italian ryegrass (Lolium multiflorum) hay. Fresh Italian ryegrass was treated with 3 days natural rainfall (56.5, 14.0 and 1.6 mm) after cutting without tedding. Rainfall effect on Italian ryegrass quality was evaluated based on Neutral detergent fiber (NDF) and acid detergent fiber (ADF), crude protein (CP), crude fat (CF), crude ash (CA) and non-fiber carbohydrate (NFC). The quality of Italian ryegrass was decreased with extending raining days. The content of neutral detergent fiber (NDF) was increased from 0.4 to 4.7% by 1 day advancement in raining. CF content was decreased from 8.1 to 32.8%. CP and CA contents did not change, but NFC content was decreased from 0.5 to 8.4%. The quality damage by the number of raining days after cutting Italian ryegrass was the lowest on the first day from exposure to rain.

Stable Isotope Analysis (SIA) of carbon and nitrogen is useful tool for the understanding functional roles of target organisms in biological interactions in the food web. Recently, mixing model based on SIA is frequently used to determine which of the potential food sources predominantly assimilated by consumers, however, application of model is often limited and difficult for non-expert users of software. In the present study, we suggest easy manual of R software and package SIAR with example data regarding selective feeding of crustaceans dominated freshwater zooplankton community. We collected SIA data from the experimental mesocosms set up at the littoral area of eutrophic Chodae Reservoir, and analyzed the dominant crustacean species main food sources among small sized particulate organic matters (POM, <50 μm), large sized POM (>50 μm), and attached POM using mixing model. From the results obtained by SIAR model, Daphnia galeata and Ostracoda mainly consumed small sized POM while Simocephalus vetulus consumed both small and large sized POM simultaneously. Copepods collected from the reservoir showed no preferences on various food items, but in the mesocosm tanks, main food sources for the copepods was attached POM rather than planktonic preys including rotifers. The results have suggested that their roles as grazers in food web of eutrophicated reservoirs are different, and S. vetulus is more efficient grazer on wide range of food items such as large colony of phytoplankton and cyanobacteria during water bloom period.

Thus far, there have been many studies focusing on meat quality improvement for Hanwoo (Korean cattle). It is considered that studies on meat quality have been actively conducted because beef consumption has changed from quantity to quality since early 1990's. Moreover, many studies on meat quality using maker assisted selection (MAS) have been conducted. However, there is a need to study quantity of meat in order to enhance the economic effect by genetic diversity and quantity of meat for Hanwoo. Therefore, in order to use a myostatin gene affecting meat quantity among quantitative genes for MAS, this study analyzed the association between genetic variation of myostatin gene in individuals of Hanwoo and carcass traits. Analysis between genotypes and individual phenotypic characteristics was performed by ANOVA using ASREML. Association analysis between these 10 SNPs and phenotypic characteristics (carcass weight, eye muscle area, backfat thickness, marbling score, yield index), and there were significant differences in 5 SNPs. As a result, there were five significant differences. Although all the SNPs did not show significant differences in each trait in this study, some SNPs showed significant differences in each trait. The diversity of myostatin gene was found in Hanwoo.

목 적 : 2014년 우리나라의 3대 사망원인 중 하나는 뇌혈관 질환이다. 그 중 큰 비중을 차지하고 있는 뇌혈관 폐색은 venogram으로 진단을 할 수 있다. venogram은 크게 PC기법과 TOF기법으로 나뉘는데 우리는 TOF기법에 대해 연구해 보았다. 2D TOF-MRA는 검사방향과 혈류의 방향이 같을 경우 계속되는 RF pulse의 영향으로 혈액 내 spin들이 포화되어 혈류신호가 감쇄하게 된다. 그래서 2D TOF-MRA검사시 oblique angle을 주고 검사를 진행한다. 이에 본 연구에서는 oblique angle의 유용성을 평가하고자 angle을 0°, 10°, 20°로 변화시켜 가며 각각의 영상을 비교 분석하여 보았다. 대상 및 방법 : 2015년 5월부터 2015년 10월까지 본원 내원해 Brain MRI을 시행한 환자중 뇌에 질병이 없는 30명(남성12명, 여성18, 연령분포 20~55세, 평균연령 35세)을 대상으로 하였다. 사용된 장비는 Skyra 3T(Siemens, Germany)이고 신호수집은 20 channel Head/Neck coil을 사용하였다. TR은 19ms, Thickness는 2.5mm, Matrix는 256×256, TE는 4.56ms, Bandwidth는 219kHz으로 설정하여 사용하였다. axial 단면에서 oblique angle을 0°, 10°, 20°로 주면서 sagittal단면으로 영상을 획득하였다. 결과 분석은 정량적과 정성적 두 가지로 하였다. 정량적 분석은 검사 후 얻은 영상에 세 곳을 정해 SNR을 측정하여 비교하였다. 정성적 분석은 영상의학과 전문의 1명과 전공의 1명 그리고 방사선사 1명이 3가지 평가항목에 대하여 Likert’s 5-point scale로 분석을 하였다. 통계분석은 SPSS 19K를 사용하였다. 결 과 : 정량적 분석의 결과 SSS의 SNR측정치 평균값은 0°-27.4155, 10°-35.4500, 20°- 44.3650으로 각도가 커질수록 SNR값도 증가 되었다. 다중비교결과 세 경우 모두 유의확률이 0.05이하로 각각의 값들이 유의한 차이를 보였다. SSC의 SNR측정치 평균값은 0°-16.6900, 10°-20.2600, 20°-26.6405으로 각도가 커질수록 SNR값도 증가 되었다. 다중비교결과 0°와10°는 0.05이상으로 차이가 없었고, 20°만 0.05이하로 유의한 차이를 보였다. DTS의 SNR측정치 평균값은 0°-82.3150, 10°-86.2850, 20°-92.5200으로 각도가 커질수록 SNR값도 증가 되었다. 하지만 다중비교결과 세 경우 모두 유의확률이 0.05이상으로 각각의 값들이 유의한 차이를 보이지 않았다. 정성적 분석의 결과 SSS는 평가자 1,2,3이 모두 각도가 커질수록 점수가 증가 되었다. 유의확률은 각각의 다중비교 결과 1,3은 유의확률이 모두 0.017이하로 유의한 차이를 보였으나 2만 10°-20°간에 유의한 차이를 보이지 않았다. SSC는 평가자 1,2,3이 모두 각도가 커질수록 점수가 증가 되었다. 유의확률은 각각의 다중비교 결과 1,3은 유의확률이 모두 0.017이하로 유의한 차이를 보였으나, 2만 0°-10°간에 유의한 차이를 보이지 않았다. DTS는 평가자 1,3은 모든값이 같게 나왔고 2만 각도가 커질수록 점수가 증가 되었다. 유의확률은 각각의 다중비교 결과 세 경우 모두 0.017이상으로 유의한 차이를 보이지 않았다. 결 론 : 정량적 분석과 정성적 분석 모두에서 대체적으로 각도가 커질수록 영상의 질이 좋아짐을 알 수 있었다. 각도의 변화는 숙련 기간이 필요하지도 않고 특별히 재구성하는 것도 없었으며 검사 시간도 늘어나지 않는다. 뿐만 아니라 검사 영상의 화질도 더 좋아진다. 그러므로 각도를 기존보다 더 크게 20° 주는 방법은 유용한 검사법이라 사료된다.

Priming 처리를 통하여 목본종자의 발아반응을 조사하고, 그에 알맞은 priming 유도 물질과 농도를 구명하고자 하였다. 35종의 목본종자에 6.7% PEG, 0.1mM GA3, 100mM KNO3, 100mM NaCl를 처리한 결과 모든 처리구에서 발아율이 증가하였고, 그 중 GA3의 처리가 가장 좋았다. 각 처리구에서 공통적으로 발아한 6수종에 대한 발아반응 조사를 시행하였다. 평균발아일수는 KNO3와 GA3 처리구에서 가장 많은 수종이 단축되었다. 발아속도는 GA3에서 가장 빨랐다. 발아치는 GA3가 가장 큰 폭으로 증가하였다. 발아율이 가장 높았던 GA3의 최적농도를 구명하였다. 수종은 발아율이 높았던 3수종과 발아율이 낮았던 2수종을 이용하였으며, GA3 농도의 경우 0, 0.01, 0.05, 0.1, 0.5, 1.0mM 농도로 각각 처리하였다. 그 결과 대조구에 비하여 모든 처리구에서 발아율, 발아속도, 평균발아일수, 발아치가 향상되었다. 특히 주요목본 수종종자의 발아에 가장 좋은 GA3 농도는 0.1mM로 나타났다. 본 연구결과는 발아율이 저조한 목본식물종자의 발아율 향상에 기여할 것으로 판단된다.

Abstract: In this study, finite element analysis modeling is proposed to evaluate middle- and low-rise steel-frame buildings constructed in South Korea. Two steel-frame joint specimens with welding joint parts were constructed and evaluated. Two types of displacement load, monotonic and cyclic, were used to evaluate the steel-frame joint specimens. According to the experimental results, the maximum moment of the cyclic test results was 80% smaller than that of the monotonic test results. Local buckling was observed in the compression area of the H-beam flange. A finite element analysis model based on the experimental results was proposed to analyze the steel-frame joint specimens. The numerical results predicted the experimental behavior of the steel-frame joint specimens well. Therefore, it is possible to use the proposed finite element analysis model to evaluate middle- and low-rise steel-frame buildings constructed in South Korea.

This study investigates the thermal shock property of a polycrystalline diamond compact (PDC) produced by a high-pressure, high-temperature (HPHT) sintering process. Three kinds of PDCs are manufactured by the HPHT sintering process using different particle sizes of the initial diamond powders: 8-16 μm (D50 = 4.3 μm), 10-20 μm (D50 = 6.92 μm), and 12-22 μm (D50 = 8.94 μm). The microstructure observation results for the manufactured PDCs reveal that elemental Co and W are present along the interface of the diamond particles. The fractions of Co and WC in the PDC increase as the initial particle size decreases. The manufactured PDCs are subjected to thermal shock tests at two temperatures of 780oC and 830oC. The results reveal that the PDC with a smaller particle size of diamond easily produces microscale thermal cracks. This is mainly because of the abundant presence of Co and WC phases along the diamond interface and the easy formation of Co-based (CoO, Co3O4) and W-based (WO2) oxides in the PDC using smaller diamond particles. The microstructural factors for controlling the thermal shock property of PDC material are also discussed.