• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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• pp.173-179
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• 2004

Combustion of refuse derived fuel(RDF) and refuse plastic fuel (RPF) was carried out in a lab-scale circulating fluidized bed. Experiment was investigated cold flow visualization. RDF was made by C & tech and RPF was made by KRS. The results include distribution of temperature in the combustion chamber, and concentrations of flue gas such as $O_2$, $CO_2$, CO, $NO_x$ and HCs Micro G.C(gas chromatograph) was employed to find out concentration of He Temperature distribution was different when RDF and RPF were burnt respectably. As air ratio became increased, $CO_2$, CO, and total of HCs emissions were decreased. According to the number of carbon atom of HCs, HC were classified as five kinds of HC.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2022년도 하계학술대회
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• pp.78-80
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• 2022

Strawberry (Fragaria × ananassa) cultivation methods are rapidly changing from traditional soil cultivation to high bed hydroponics, which are easy to agricultural working. The objective was to evaluate the growth characteristics of three strawberry cultivars cultivated high bed system. The "Seolhyang", "Altaking", and "Keumsil" strawberry plants were transplanted in a glass-type greenhouse at Kyungpook National University Gunwi Agricultural Field. The cultivation period was approximately seven months from September 17, 2021 to April 21, 2022. Growth parameters measured including the number of leaves, plant height, petiole length, leaf length, leaf width, and crown diameter at two-week intervals. The environmental parameters for each location in the greenhouse were collected. Plant height in all cultivars continued to decrease from the early stage to the late stage of growth. The crown diameter was increased by 50 DAT, and then gradually decreased until late growth stage in all cultivars. Results indicated that the growth parameters represented to vary according to the cultivar of strawberry plants.

• 대한설비공학회지:설비저널
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• 제16권1호
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• pp.81-88
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• 1987

In this paper, the local effective thermal conductivities and calculated by using the actual temperature distribution in packed bed. The variations of these are investigated for radius and air stream direction, flow rate and particle diameter. The resulting local effective thermal conductivi-ties are classified in the inner zone of bed and vicinity zone of the wall surface. Also these are related to dimensionless axial direction position, radius direction position, and particle diameter and Reynolds number which uses particle diameter as the characteristic length. If these correla-tions are represented by function, the equation is showed in Eq. (3-4). This equation is well satisfied with experimental results within $\pm25\%.$

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2088-2093
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• 2008

In this study, flow field measurement of the Pebble Bed Reactor(PBR) for the High Temperature Gas-cooled Reactor(HTGR) was performed. Large number of pebbles in the core of PBR provides complicated flow channel. Due to the complicated geometries, numerical analysis has been intensively made rather than experimental observation. However, the justification of computational simulation by the experimental study is crucial to develop solid analysis of design method. In the present study, a wind tunnel installed with pebbles stacked was constructed and equipped with the Particle Image Velocimetry(PIV). We designed the system scaled up to realize the room temperature condition according to the similarity. The PIV observation gave us stagnation points, low speed region so that the suspected high temperature region can be identified. With the further supplementary experimental works, the present system may produce valuable data to justify the Computational Fluid Dynamics(CFD) simulation method.

• 대한원격탐사학회지
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• 제29권5호
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• pp.527-535
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• 2013

분광혼합분석을 효과적으로 수행하기 위한 정확한 endmember의 추출은 반드시 선행되어야할 조건이며, 이를 위한 다양한 endmember 추출 알고리즘들이 개발되었다. 이러한 endmember 추출 알고리즘의 개발 및 적용성을 평가하기 위한 기존의 연구는 대부분 모의 초분광 영상 또는 AVIRIS 영상을 대상으로 진행되었다. 그러나 이러한 영상 자료는 실제 국내에서 획득되고 활용할 수 있는 초분광 영상과 차이를 보일 수 있다. 따라서 본 연구에서는 국내에서 취득된 AISA 초분광 영상에 대하여 대표적인 endmember추출 알고리즘을 사용하고, 그 적용성을 평가하였다. 물질의 종류 및 크기에 따른 차이를 분석하기 위하여 인공적으로 설계한 테스트베드를 구축하고, AISA 초분광 영상을 취득하여 실험 자료로 이용하였다. 실험결과, 테스트베드 내 물질과 초기 입력값에 따라 알고리즘별로 endmember 추출결과가 다르게 나타났다. 따라서 효과적인 endmember 추출 알고리즘을 적용하기 위해서는 영상을 구성하는 테스트베드 내 물질의 특성 및 최적의 endmember의 개수를 고려해야 할 것이다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2023년도 춘계학술대회
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• pp.79-79
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• 2023

With the development of digital technology, the size of the smart agriculture market at home and abroad is rapidly expanding. It is necessary to establish a foundation for sustainable precision agriculture in order to respond to the aging of rural areas and labor shortages. This study was conducted to establish an automated digital agricultural test bed for soybean production management using data suitable for agricultural environmental conditions in Korea and to demonstrate the field of leading complexes. In order to manage water smartly, we installed a subsurface drip irrigation system in the upland field and an underground water level control system in the paddy field. Based on data collected from sensors, water management was controlled by utilizing an integrated control system. Irrigation was carried out when the soil moisture was less than 20%. For effective water management, soil moisture was measured at the surface, 15cm, and 30cm depth. The main growth characteristics and yield, such as stem length, number of branches, and number of nodes of the main stem, were investigated during the main growth period. During the operation of the test bed, drought appeared during the early vegetative growth period and maturity period, but in the open field smart agriculture test bed, water was automatically supplied, reducing labor by 53% and increasing yield by 2%. A test bed was installed for each field digital farming element technology, and it is planned to verify it once more this year. In the future, we plan to expand the field digital farming technology developed for leading farmers to the field.

• 한국전산유체공학회지
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• 제15권1호
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• pp.9-16
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• 2010

The characteristics of flow and heat transfer in a bubbling fluidized bed are investigated by means of computational fluid dynamics (CFD). To simulate two-phase flow for the gas and solid flows, Eulerian-Eulerian approach is applied. Attention is paid for a heat transfer from the wall to fluidized bed by bubbling motion of the flow. From the result, it is confirmed that heat transfer is promoted by chaotic bubbling motion of the flow by enhancement of mixing among solid particles. In particular, the vortical flow motion around gas bubble plays an important role for the mixing and consequent heat transfer. Discussion is made for the time and space averaged Nusselt number which shows peculiar characteristics corresponding to different flow regimes.

• 한국해안·해양공학회논문집
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• 제21권6호
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• pp.470-479
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• 2009

파에 의한 국부세굴은 하상재료의 지질학적 특성과 해저 하상의 유동은 물론, 수리학적 조건에 의해서도 영향을 받게되는 매우 복잡한 종합적 과정으로 생각할 수 있다. 지금까지의 대부분의 연구는 세굴심을 중점 대상으로 하였으나 전체 국부 세굴량 산정에 있어서 세굴 폭과의 관련성은 상대적으로 미미하게 다루어져왔다. 많은 국부세굴 영향인자 중에서도 파의 크기 혹은 해저 바닥에서의 유속은 국부세굴의 직접적인 원인으로서 작용하며, 이를 포함하는 Ursell 수나 KC 수 등의 무차원 매개변수는 세굴 영역과의 상관성 분석을 통해 세굴심이나 세굴폭을 예측할 수 있는 수단이 될 수 있다. 본 논문에서는 이러한 무차원 매개변수와 세굴 폭과의 관계를 규명하기 위해, 관경, 파고, 주기를 변화시키며 실험을 수행 및 분석하였다. 그 결과, Re 수나 주기 매개변수 등은 국부세굴 폭과 큰 분산을 보인 반면에 shields 수와 KC 수, Ursell 수는 좋은 상관성을 나타내었다. 특히 shields 수는 세굴심에 큰 영향을 주지 못하는 반면 세굴 폭과는 밀접한 관계를 보이고 있다.

• 한국환경과학회지
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• 제24권2호
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• pp.197-205
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• 2015

This study was performed to identify the effect of fertilizer application and planting method on growth and yield of 'Seolhyang' strawberry during seedling raising. According to the concentration of fertilizer applied, the height of daughter plants was the highest at an EC of $0.8dS{\cdot}m^{-1}$. Leaf number and crown diameter were greatest at an EC of $0.6-0.8dS{\cdot}m^{-1}$. In the first measurement, root number was highest in non-fertilizer application, while root weight was heaviest in non-fertilizer application and EC $0.4dS{\cdot}m^{-1}$. The higher the concentration of fertilizer applied as culture media, the lower the growth rate. Thirty days after planting on the main field, plant height and number of new leaf were highest at an EC of $0.8dS{\cdot}m^{-1}$. However, no significant difference was found in leaf length and width and chlorophyll content according to fertilizer application. Marketable yield of 25 g or higher was greatest in EC $0.6dS{\cdot}m^{-1}$. In contrast, no significance was found in total marketable yield at an EC of $0.4-0.8dS{\cdot}m^{-1}$. Aconsistent pattern was exhibited in the growth of 1-5 harvesting flower clusters according to planting method. The length of leaf and flower cluster was short and chlorophyll content was low, when bed soil was removed 100% in harvesting of the first flower cluster. In all treatment, leaf length was shortened until harvesting of the second and third flower cluster, but rapidly lengthened in harvesting of the third and fourth flower clusters. Moreover, the length of flower cluster had a increasing tendency from harvesting of the third flower cluster. However, chlorophyll content was reduced continuously until harvesting of the fifth flower cluster, and was lowest in harvesting of the fourth flower cluster without removal of bed soil. Total yield was greatest in treatment of crown removal in bed soil between November and May. Late marketable yield between March and May was highest in treatment of 100% bed soil removal, followed by treatment of crown removal. Marketable yield of 25 g or higher was greatest in treatment of crown removal between December and February, while greatest in treatment of 100% bed soil removal between March and May.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권3호
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• pp.268-272
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• 2006

A dense, pellicular UpFront adsorbent ($p=1.5 g/cm^3$, UpFront Chromatography, Cophenhagen, Denmark) was characterized in terms of hydrodynamic properties and protein adsorption performance in expanded bed chromatography. Cibacron Blue 3GA was immobilised into the adsorbent and protein adsorption of bovine serum albumin (BSA) was selected to test the setup. The Bodenstein number and axial dispersion coefficient estimated for this dense pellicular adsorbent was 54 and $1.63{\times}10^{-5}m^2/s$, respectively, indicating a stable expanded bed. It could be shown that the BSA protein was captured by the adsorbent in the presence of 30% (w/v) of whole-yeast cells with an estimated dynamic binding capacity $(C/C_o = 0.01)$ of approximately 6.5 mg/mL adsorbent.