Korean melon (Cucumis melo L.) is an environment in which most farming work can affect the increase in musculoskeletal diseases, and the stems are attracted to the ground in order to grow no-heating cultivation. In this study, growth and productivity were compared according to the type of high-bed. The narrower the surface area at the bottom of the high-bed, the faster the initial growth, which was advantageous. The bed is which the height if 70 cm, the surface temperature has risen due to the increase in direct solar radiation inflow since April, requiring side light blocking to block the inflow of solar radiation. In terms of fruit quality, the 200 cm width treatment had higher fruit sugar content and better hardness than the 160 cm treatment. From April to September, the total yield was 6.8 kg/plant of treatment A, 8.7 kg/plant of treatment B, 5.8 kg/plant of treatment C, treatment B mainly 50% higher than treatment C, and 27% higher than treatment A. Therefore, the bed form suitable for Korean melon high bed is 200 cm wide, 40 cm high between the surface and the bed, and the surface of the passage between the beds is 30cm high from the ground to the bed.

In this study, the effect of crown heating on the cultivation environment, budding, flowering and yields of strawberry was analyzed. In December, January, and February, when the outside temperature was low, the average strawberry crown temperature at daytime in the test zone was 1.3°C higher than that in the control zone, and the average strawberry crown temperature at nighttime in the test zone was 2.7°C higher than that in the control zone. The average bed temperature at daytime in test zone was 1.7°C higher than that in the control zone, and the average bed temperature at nighttime in test zone was 2.4°C higher than that in the control zone. As a result of performing correlation analysis and regression analysis on strawberry crown temperature and budding period, the correlation coefficient was -0.86, which tended to be shorter as the crown temperature was higher, and the determination coefficient was 0.74. The total yields of strawberry during test period were 392.6 g/plant for test greenhouse and 346.0 g/plant for control greenhouse respectively. As for the quality of strawberries, the ratio of 2L (very large) grades and L (large) grades was 62.4% in the test greenhouse and 58.5% in the control greenhouse, indicating that the proportion of high quality strawberries was higher in the test greenhouse.

Recently, considerable attention has been given to nickel-based superalloys used in additive manufacturing. However, additive manufacturing is limited by a slow build rate in obtaining optimal densities. In this study, optimal volumetric energy density (VED) was calculated using optimal process parameters of IN718 provided by additive manufacturing of laser powder-bed fusion. The laser power and scan speed were controlled using the same ratio to maintain the optimal VED and achieve a fast build rate. Cube samples were manufactured using seven process parameters, including an optimal process parameter. Analysis was conducted based on changes in density and melt-pool morphology. At a low laser power and scan speed, the energy applied to the powder bed was proportional to and not . At a high laser power and scan speed, a curved track was formed due to Plateau-Rayleigh instability. However, a wide melt-pool shape and continuous track were formed, which did not significantly affect the density. We were able to verify the validity of the VED formula and succeeded in achieving a 75% higher build rate than that of the optimal parameter, with a slight decrease in density and hardness.

In this study, the high-temperature oxidation properties of austenitic 316L stainless steel manufactured by laser powder bed fusion (LPBF) is investigated and compared with conventional 316L manufactured by hot rolling (HR). The initial microstructure of LPBF-SS316L exhibits a molten pool ~100 μm in size and grains grown along the building direction. Isotropic grains (~35 μm) are detected in the HR-SS316L. In high-temperature oxidation tests performed at 700oC and 900oC, LPBF-SS316L demonstrates slightly superior high-temperature oxidation resistance compared to HR-SS316L. After the initial oxidation at 700oC, shown as an increase in weight, almost no further oxidation is observed for both materials. At 900oC, the oxidation weight displays a parabolic trend and both materials exhibit similar behavior. However, at 1100oC, LPBF-SS316L oxidizes in a parabolic manner, but HR-SS316L shows a breakaway oxidation behavior. The oxide layers of LPBF-SS316L and HR-SS316L are mainly composed of Cr2O3, Febased oxides, and spinel phases. In LPBF-SS316L, a uniform Cr depletion region is observed, whereas a Cr depletion region appears at the grain boundary in HR-SS316L. It is evident from the results that the microstructure and the hightemperature oxidation characteristics and behavior are related.

본 연구에서는 고설 딸기 관부(크라운부) 난방시스템을 전기 온수 보일러, 축열조, 순환 펌프, 관부난방 배관 (백색 연질 PE관, 관경 16mm) 및 온도 제어반으로 구성하였다. 관부(크라운부) 난방의 경우 난방 배관을 딸기 관부에 최대한 밀착될 수 있도록 설치하고 배관 위치를 원예용 고정핀으로 고정하였다. 또한 관부 난방시스템의 에너지 효율을 증진하기 위해 축열조 온수 온도를 20~23oC, 관부 온도를 13~15oC로 관리하였다. 관부난방은 전기 온수보일러를 이용하여 20~23oC의 온수를 축열조에 저장하고 순환펌프를 제어하기 위한 온도 센서를 딸기의 관부에 최대한 근접하여 설치하고 온도를 감지함 으로써 관부(크라운부)를 집중적으로 난방하는 방식이다. 시험 온실의 난방 처리는 공간 난방 4oC + 관부난방(처 리 1), 공간 난방 8oC (대조구), 공간 난방 6oC + 관부 난방(처리 2)로 처리하였다. 각 난방처리는 온실 1동에 딸기를 980주를 심었으며, 재배방법은 표준재배법에 준해서 재배하였다. 난방 에너지 소비에 대한 비교시험은 2017년 11월 8일부터 2018년 3월 30일까지 수행되었다. 소비된 누적 전력량은 등유 사용량으로 환산하였고, 등유 소비량은 공간난방 8oC(대조구)의 경우 1,320L (100%), 공간난방 4oC + 관부난방의 경우 928L(70.3%), 공간난방 6oC + 관부난방의 경우 1,161L (88%)로 계측 되었다. 공간난방 4oC + 관부난방(처리 1) 및 공간난방 6oC + 관부난방(처리 2)은 8oC 공간난방(대조구)에 비해 생육 저하, 수확시기의 지연 등이 없이 비슷하게 딸기 수확이 가능하였으며, 29.7% 및 12%의 난방 에너지가 절감되는 것으로 분석되었다.

Five empirical farmhouses were selected to reduce the high temperature damage in oak mushroom cultivation using bed-logs. The cultivation facilities were categorized as follows: those having two blackout curtains or one blackout curtain and outdoor oak mushroom cultivation. The inequality of the indoor condition, oak mushroom hyphae rampant ratio, and fruit body production in each test condition was evaluated. 3oC was lower in indoor temperature of cultivation facility having two blackout curtains than one blackout curtain. Specifically, the indoor air humidity average of cultivation facilities having one or two blackout curtains was 10% lower than that of outdoor oak mushroom cultivation. This condition is not ideal for oak mushroom cultivation as continuous indoor humidity control is essential for producing good fruit bodies. The Inoculated bed-log surface and oak mushroom hyphae rampant ratio of bed-logs cultivated with two blackout curtains was superior to other tested conditions. The mushroom production ratio observed in facilities with two blackout curtains was 117-204% higher than those cultivated in facilities with only one blackout curtain. Furthermore, the mushroom production ratio increased in based on these findings, we recommended five cultivation facility models to reduce high temperature damage in oak mushroom cultivation using bed-logs.

This study aimed to develop the movable bed cultivating system for strawberry cultivation that enables to increase crop yield and save labor through high-density cultivation. In comparison with a conventional raised-bed system, the best feature of the system is a culture bed moving freely, left, right, up and down. This system consists of four devices; longitudinally- and laterally-moving device, nutrient solution supply device, and a control device. A comparative study showed that there was no significant difference on strawberry growth between a conventional raised bed and the movable bed cultivation systems. In addition, the change of growing environment to high-density cultivation did not influence strawberry growth, which proved the applicability of the movable bed cultivation system. Additional finding of this study showed that about 1.7 times more plants can be planted in movable beds. High-density cultivating using movable beds enables to plant more strawberry within the same cultivated area, which eventually contribute to reduce energy consumption per strawberry.

본 연구는 딸기의 2단 고설베드재배가 끝난 여름철 동안 수박재배 시, 베드 위치와 재식밀도가 수박의 과실 품질에 미치는 영향을 구명하고자 하였다. 고설 베드상자는 길이 102cm, 폭 22cm, 높이 13cm의 규격이고, 배지는 코코피트(coir)를 사용하였다. 수박은 베드 위치 및 재식밀도에 따라 베드상단 1주(A), 베드 상하단 각 1주로 상단(B) 및 하단(C), 상하단 각2주로 상단 2주(D), 하단 2주(E)로 정식 처리하였다. 수박은 2012년 5월 8일에 2단 고설베드에 정식하여 양액과 점적관수로 재배하였고 7월 25일에 수확되었다. 수박의 품질을 비교하고자, 과실 무게와 크기를 조사하였고, 과육 내 비타민 C, 플라보노이드, 페놀화합물, 당도 및 산도 등의 기능성 화합물을 분석하였다. 과실의 외관 품질인 과고, 과폭 및 과중은 A처리가 다른 처리에 비하여 가장 높았다. 특히 과중은 A, B, C, D, E처리 순으로 무거웠다. 식물체의 초장이나 엽수는 유의적 차이가 없었으나 줄기 직경과 엽면적은 A처리가 유의하게 컸다. 수박 과육 내플라보노이드, 항산화 활성 및 산도는 처리 간에 유의적 차이가 없었다. 한편 당도는 A, B 및 D 처리에서 유의하게 높게 나타났다. 또한 페놀화합물 함량은 A처리가 가장 높았다. 이상의 결과로 보아 대과의 수박 생산을 위해서는 A처리, 소과의 수박 생산에는 D와 E의 처리가 유리할 것으로 판단되었다.

본 연구는 하상재료의 종류와 유속에 따른 세굴변화에 대한 연구를 진행하였고, 유속, 구성방법 및 재료와 세굴에 대한 상관관계를 정의하여 호안 및 제방의 운용성을 검토하고자 실험을 통한 연구를 진행하였다. 본 연구의 실험에 사용된 재료는 제방에 사용되고 있는 재료로 모래, 황토를 이용 하였다. 실험실규모 고속수로에서 다양한 계측장비들을 이용하여 유속의 변화에 따른 재료의 세굴을 측정하였다. 이를 통해 세굴 전·후의 재료변 화를 수치적으로 분석하였다. 고유속흐름에서 하상재료에 따라 세굴의 정도를 비교·평가하여 안정성에 대한 연구도 진행하였다. 실험 결과 모래의 경우 응집력이 매우 약하여 1.0 m/s 이하에서도 40% 이상의 재료가 유실이 되고 황토의 경우 모래보다 유속이 빠른 2 m/s 이상에서도 6% 이하 의 재료가 유실이 되었다. 재료가 유실된 이유중 하나는 강한 응집력으로 건조균열이 발생하여 세굴에 취약한 결과를 보였다. 본 연구에서는 이러한 건조균열의 발생부터 재료가 유실되는 현상을 제거하는 방법부터 재료에 대한 구성과 유실정도를 평가 하였다.

In this paper, the filed test procedure for evaluating the performance of track structure for additional Speed-Up test on Test-Bed Section(KP 100∼128km Osong starting point). The behavior of track system corresponding the speed up of train will be identified by the analysis of the measured data.

Needs for a new technologies of infrastructure systems arose, following the development of next generation EMU(Electric Multiple Unit) train with maximum speed over 400km/h. For high-speed operation tests of the new EMU, a high-speed railway infrastructure test-bed was constructed in a 28km long section of the Honam High-speed Railway. Diverse sensors and monitoring system was installed for continuous monitoring of the railway. Due to such effort, further demands and needs of the integrated monitoring system was derived in a more comprehensive and long-term perspective.

In this paper, sensors and equipments for monitoring the weather in test-bed of Honam high-speed railroad are introduced, and integrated monitoring system linked to weather information and its management plan are suggested.

In this study, it explains briefly the test procedure for evaluating the performance of roadbed in test-bed section of Honam high-speed railway.

In this study, it explains briefly the test procedure for evaluating the performance of track and bridge in test-bed section of Honam High-Speed Railway.

Recently, power distributed high-speed train with 430km/h(HEMU-430X) has developed in korea, 2012. However, the development of the train alone can not achieve the speed of high-speed rail system. So it needs the development of infrastructure system. In this paper, the project named “Application & technology development of high-speed rail infrastructure for 400km/h-class” being promoted in december 2010 will be introduced comprehensively.

최근 기후변화에 기인하는 유출특성 변화와 유역 및 하도 환경 변화에 따라 하도형태가 바뀌는 경향을 보이고 있다. 특히 지속적인 성장세를 보이고 있는 하도내 국지퇴적이 전국에 걸쳐 중 대하천에서 야기되고 있다. 이 가운데 고수부지 형태로 나타나는 복단면 하도에서 홍수터가 일방향적 성장과 저수로의 저하현상이 현저한 것으로 나타나고 있다. 이와 같은 현상은홍수량 관리는 물론 하천생태관리에도 영향을 미치고 있는것으로 평가되고 있다. 본 연구에서 우리나라에서의