In the present study, the experimental study was conducted using a multi-calorie meter, to investigate the cooling performance and cycle operation changes of the multi-heat pump (3 indoor units) for the low outside temperature in summer. The test temperature condition was the low cooling temperature, and the normal performance and dynamic behavior of 3 rooms, 2 rooms, and 1 room were measured to understand the operating characteristics of seven 7 indoor unit combinations. As a result of the experiment, the cooling capacity and COP of the multi-heat pump at low cooling temperature were about 10% and 6% higher than those of the cooling standard temperature. In addition, the dynamic behavior of the indoor units of 3 and 2 rooms was observed differently due to the load difference according to the indoor unit combinations and the non-uniformity of the refrigerant amount. And, when starting the heat pump, the compressor had a maximum peak value and stabilized by repeating the decrease and increase for each indoor unit combination.

In the present study, to investigate the cooling characteristics of the multi-heat pump with 3 indoor units, 7 indoor unit combinations and 3 setting temperatures are selected to study the cooling characteristics during steady-state operation. The cooling capacity, power consumption, COP, compressor high and low pressure of the heat pump are tested under the cooling standard temperature conditions using an air enthalpy multi-calorimeter. The experimental results show that, except for an operation with an indoor unit capacity of 30% or less, the cooling capacity, power consumption, and compressor operation frequency increase as the capacity of the indoor unit increases and the setting temperature of the indoor unit decreases. COP increases or decreases according to the compressor frequency, and is the best at 50-80% capacity of the indoor unit. As the compressor frequency increases, the compressor outlet pressure increases by about 30%.

In order to experimentally investigate the operation characteristics of the multi-heat pump with 3 indoor units, the dynamic characteristics of the cooling cycle is studied using the psychrometric multi-calorimeter. The compressor of the heat pump is the scroll inverter type, and since 3 indoor units operate cooling at the same time, it is operated at 100% full load. In particular, 3 types of indoor unit temperatures (20, 24, 26°C) are selected to understand the operation process of the multi-heat pump by the setting temperature. From this experiment, the compressor controls the EEV opening for each indoor unit while varying the frequency according to the initial start, transient, and steady operation. In addition, as the setting temperature increases in the steady range, the frequency of the compressor and the average opening degree of the EEV decrease.

In the present study, it is conducted to understand the heating performance and compressor operation characteristics according to 7 indoor unit combinations and 3 setting temperatures of the inverter multi-heat pump under heating standard temperature conditions. Heating capacity, COP and compressor frequency are investigated using the multi-calorimeter. The indoor unit combinations are simultaneous operation(A+B+C), partial operation(A+C, A+B, B+C) and independent operation(A, B, C), and the setting temperature is 20, 21, and 30°C. Since the increase in the setting temperature increases the compress frequency, the heating capacity increases, but COP decreases due to the increase in power consumption. The frequency increases as the indoor unit combination capacity increases, and decreases as the setting temperature decreases in the steady state.

The performance characteristics and usefulness of the duct-type gas removal system to which the catalytic combustion method was applied were investigated by experiment. Benzene, toluene, ethylbenzene, and xylene were selected for performance tests on gas detection and removal of the catalytic combustion system. Accelerated experiments were performed to evaluate the gas sensing performance, the adsorption performance of activated carbon, and the basic performance and durability of the catalytic combustion system. The amount of gas adsorption in the adsorption stage was changed according to the type of activated carbon, adsorption temperature and time. The adsorption amount increased with increasing temperature and particle size. BTEX gas removal rate was about 96%, and the performance of the module was maintained for more than 4,000 hours.

In this paper, a heat exchange system using cooling dehumidification and mixing process was proposed as an experimental study for a white smoke reduction heat exchanger system under winter condition. The white smoke reduction heat exchange system is divided into an EA part, SA part, W part and mixing zone. For the operating conditions, three types (Cases 1, 2, and 3) were selected depending on whether EA fan, SA fan, and A-W heat exchanger were operated. In addition, in order to visualize the white smoke exhausted from the mixing zone, it was photographed using CCTV. In order to investigate the performance of the white smoke reduction heat exchange system, the temperature reduction rate and absolute humidity reduction rate of EA and the heat recovery rate of W were calculated. The temperature change of EA and SA according to operating conditions was most effective in Case 3, and the temperature and absolute humidity at the outlet of the mixing zone were greatly reduced. From the results of the white smoke visualization, it was confirmed that the white smoke generation mechanism was different depending on the operating conditions, and the amount of white smoke generation was greatly reduced.

In order to study the drying performance of the dryer, the performance characteristics of the heat pump dryer applied a PF heat exchanger is applied were experimentally investigated. The capacity, COP, drain and SMER of the dryer were measured by the refrigerant charge and EEV opening. Heat pump dryers are refrigerant-air systems. For the dryer performance test, an air enthalpy calorimeter was used. From the experimental results, the heat exchanger performances according to the change in the refrigerant charge and EEV opening were the maximum at 0.5kg refrigerant and 30% EEV opening, respectively. In addition, SMER suggested a satisfactory level of drying performance. This shows that the refrigeration cycle of the dryer must be operated at an appropriate refrigerant amount and EEV opening degree to secure optimal drying performance. On the other hand, the time to reach the target setting temperature of the dryer was increased by about 2.5 times depending on with/without the sample.

Driving safety of a semi-trailer is greatly reduced when driving in a section with a narrow turning radius, so a dynamic study of driving and road conditions is required. In this study, the driving stability of the semi-trailer was investigated using the RecurDyn program in consideration of the velocity and weight of the semi-trailer in the entrance curve section of the highway, and the turning angle and radius of the curved road. In order to select the model and analysis conditions according to the road type, the sloping curved road was modeled by selecting the curvature, entry length, height difference, and entrance angle of the curved section. From the analysis results, the higher the semi-trailer's entrance velocity, the heavier the weight, the narrower the entrance angle of the curved road, and the smaller the curvature, the greater the semi-trailer's maximum running angular speed which had an effect on driving stability.

In the present paper, the natural fiber materials that can be replaced to reduce the weight of the vehicle are analyzed by bubble charts of - and - , and the possibility of alternative application of materials is investigated. For this purpose, the driving energy and fuel efficiency of the vehicle using the data of K model analyzed. In addition, the effect of vehicle weight on fuel efficiency was analyzed through the dynamic analysis approach of the vehicle. From the research results, the following results were obtained. Most of natural fibers have lower density and equal tensile strength and strain than metal materials. Therefore, the application rate of natural fiber materials should be increased in consideration of the application purpose and material characteristics of the vehicle. The major variables that greatly influence driving energy and fuel efficiency were fuel efficiency improvement of about 10% in order of speed, rolling resistance and mass. In addition, when steel is lightened by 10%, fuel efficiency improvement of up to maximum 4.5% is shown in the order of CFRP, Al, Ti.

Global climate change and increased international travel have affected the transmission of mosquito-borne diseases. In South Korea, uncommon diseases such as Dengue, chikungunya and Zika virus could be transmitted by potent mediator like Aedes albopictus. In order to cope with the risk of mosquito-borne diseases, rapid mosquito monitoring system is needed. Current mosquito monitoring procedures include installation of outdoor traps-mosquito collection-species classification-analysis of disease detection – upload of information to government research institutes – disease alert. In this process, species classification takes a lot of time, and if we reduce the time, we can cope with the disease outbreak more quickly. In this study, we developed automate species classification system target for 5 mosquito species (Culex pipiens, Cx. tritaeniorhynchus, Ae. albpictus, Ae. vexans, Anopheles spp.) disease vector live in South Korea. After modeling the morphology of each mosquito species, machine learning was carried out using DenseNet (Densely Connected Networks), one of the models of Artificial Neural Network. Using the learned model, we tested the classification of 5 species of mosquitoes and showed the accuracy from 97.35% to 99.48% at the maximum. Future research will focus on increasing the number of identifiable mosquito species and reducing the time spent on species classification. The autonomous classification of mosquito species using Deep Learning technology will contribute to the development of mosquito monitoring system and public health.

In the present study, the structural and fatigue analysis on the shape change of an automatic press are investigated for prediction of operation safety and reliability of the automatic press along the thickness(t) and length(L) of head, and corner shapes(case 1, 2, 3). The equivalent stress and deformation characteristics of the automatic press were studied by computerized analysis method for the bushing production of the seat frame. An external stress of 14.0 MPa was applied to predict the operation stability and the fatigue limit of the structure. As the thickness of the header increased and the length of the header decreased, the load stability applied by the piston improved and the maximum stress and deformation were reduced. In addition, due to the change in shape of the corners, the load applied at the cross-sectional area of the corners decreases, and then the maximum stress and deformation appearing in the header are reduced. That is, the change of corner shapes affects the equivalent stress and deformation. That is the change of corner shapes affects the equivalent stress and deformation. From the fatigue and vibration analysis, fatigue failure does not occur even when the number of alternating operation of the automatic press increases, and the natural frequency is predicted for dynamic characteristics.

This study was carried out to investigate the effects of stocking density on eating and ruminating behavior of Hanwoo steers (Bos taurus coreanae) in the finishing period. A total of 30 finishing Hanwoo steers (631.3 ± 11.4 kg, 25 months old) were allocated to one of four stocking density groups comprising 1, 2, 3, and 4 steers per 32 m2 pen [G1 (32 m2), G2 (16 m2), G3 (10.7 m2) and G4 (8 m2), respectively] in triplicate. Eating, rumination behaviors, as well as dry matter intake of steers were measured, and the results were subjected to analysis of variance with stocking density as the main effect. The results of eating behaviors over 48 hours are summarized as follows: Total intake was significantly (p<0.01) higher in G1, G2, and G3 compared to G4. Eating time was not different among the treatments, whereas ruminating time increased in the order of G1 > G2 > G3 > G4 (p<0.01). However, resting time and chewing time (sum of eating and ruminating) were not significantly different among the treatments. Number of boluses and number of total chews were highest in G1 (p<0.01), whereas number of chews per bolus was highest in G3 (p<0.01). Ruminating time per bolus as well as number of boluses per minute was not significantly different among the treatments. Number of defecations was higher in G1 and G2 animals compared to G3 and G4 animals (p<0.01). However, stocking density had no effect on drinking or urination. In conclusion, increasing stocking density (i.e. G4) per pen decreased voluntary intake, ruminating time, and total chewing number in the finishing period of Hanwoo steers. However, care must be taken in discussing stocking density in the present study as the space allowance per animal was satisfactory to meet the current animal welfare regulation in Korea and in Europe, although the beef production system in Korea is more intensive than in Europe.

Near-isogenic lines (NILs) carrying bacterial blight resistance genes (Xa4, xa5 and Xa21) were developed in japonica rice using Suweon345 as genetic background. NILs were selected by gene specific DNA markers and inoculation of K1 or K3a race. NILs conferring Xa4 were resistant to K1, K2, K3, and moderately resistant to K3a. NILs conferring xa5 were resistant to K1, K2, K3, and K3a. NILs having Xa21 were susceptible to K1, while resistant to K2, K3 and K3a. Target genes of NILs with the genetic background of Suweon345 were also confirmed by using eleven Philippines races and International Rice Bacterial Blight (IRBB) NILs carrying Xa4, xa5 and Xa21. All NILs had no significant difference from their recurrent parents in the major agronomic traits except for panicle length and brown rice 1,000 grain weight. Heading date of NILs ranged from Aug. 10 to Aug. 11, which was similar to that of recurrent parent, Suweon345. Culm length, number of grains per panicle and ratio of ripened grain of NILs were similar to those of Suweon345. Milled rice of NILs was ranged from 4.82 to 4.93MT/ha. These NILs will be useful for improving resistance to K3a race of bacterial blight pathogens in Korean japonica cultivars.

2003년에 이상적으로 많이 발생하여 벼에 심각한 피해를 가져온 혹명나방의 재배방법별, 엽록소 함량별 피해실태를 조사하여 피해에 따른 수량반응, 미질변화 등을 구명하고자 조사한 결과는 다음과 같다. 1. 혹명나방의 피해가 심할수록 벼의 등숙비율, 천립중의 감소와 복백립 등 미숙립의 증가에 따른 완전미 비율이 감소되어 완전미 수량이 피해가 심한 곳에서 36% 감소되었다. 2. 혹명나방의 피해가 심할수록 쌀의 외관상 품위가 떨어질 뿐만 아니라 단백질함량이 높아져 식미치는 감소되어 미질이 급격히 저하되었다. 3. 질소질 비료의 시용량이 증가할수록 혹명나방에 의한 피해는 증가하였으며, 특히 주남벼의 경우 질소량이 증가할수록 피해가 급증하였다. 4. 질소 시비량이 추천 시비량인 11 kg/10a를 초과시 피해엽율이 60% 이상으로 급증하였고, 60% 이상 피해를 입은 엽의 비율도 25%이상으로 늘어나 수량 감수 요인으로 작용하였다.

Hanmaeum is a new super-yielding japonica rice cultivar developed from a three-way cross of Mi1yang165,YR16365Acp13 and Iksan438 at Honam Agricultural Research Institute (HARI), RDA, in 2004. This cultivar has about 119 daysgrowth duration from transplant

Two rice cultivars of the japonica type, ozone-resistant Ilpumbyeo (IL) and ozone-susceptible Keu-mobyeo#l (KM) were exposed to ozone (O3 ) at 0.15 ppm for 30 days. The available nutrient regimes were varied by doubling the supply of nitrogen (N), phosphorus (P) and potassium (K) within a basic fertilizer status (N, P, K; 15, 12, 12 kg l0a-1 ). There was little difference on plant height between ozone-treated and nontreated plants. The most significant ozone stress on tiller number was shown on the 30th day of ozone exposure. Slight recovery from ozone stress was noted on the 60th day. On the 30th day, tiller number was greatly decreased by 40.8% in IL and 64.6% in KM, whereas at a high nitrogen supply regime (2N), it was decreased by 21.4% in IL and 42.7% in KM as compared to the control not treated with ozone at basic fertilizer status. The inhibition of tiller production caused by ozone exposure was alleviated on the 60th day. In both cultivars, number of spikelets per plant and weight of 100 grains were affected little by the ozone treatment irrespective of nutrient regime. However, the number of panicles per plant and yield were reduced significantly. In both cultivars, yield of ozone-treated plants with 2N status was 12.4-16.1 % higher than that of the ozone-treated plants with basic nutrient status. A significant yield decrease of 47.8% and 33.4% was observed for IL and KM, respectively, in ozone-treated plants with higher potassium (2K) status.

Ozone (O3 )-induced changes in chlorophyll content and specific activities of antioxidant enzymes, such as superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) were investigated in two rice cultivars (Oryza sativa L.) grown under variable nutrient treatments. For this study, two rice cultivars of Ilpumbyeo (IL) and Keumobyeo#l (KM), which were known as resistant and susceptible to O3 , respectively, were exposed to O3 at 0.15ppm for 30 days and investigated with 10 days interval. The available nutrient regimes were varied by doubling the supply of nitrogen (N), phosphorus (P) and potassium (K) Within a basic fertilizer status (N, P, K; 15, 12, 12kg/l0a-1 ). In both cultivars and at all nutrient status, chlorophyll content in O3 -treated plants decreased with prolonged treatment period, although higher N, P and K supply with O3 treatment alleviated the decrease in chlorophyll content. The activities of almost all enzymes investigated for this study were decreased during initial stages of O3 - exposure except GPX which maintained higher activity throughout the exposure period than the non-treated plant. However, the antioxidant enzymes in O3 -treated plants showed almost the same or higher activities on 30 days after O3 - exposure. The most significant changes in activities were observed in GR of the O3 -treated leaves. With the prolonged treatment period, the activity of GR at 30 days was increased by 3-8 times compared to those in 10 days. Most of the investigated enzymes showed very similar tendency to O3 treatment in all fertilizer status. There was no observed evidence for enhanced detoxification of O3 -derived activated oxygen species in plants grown under higher fertilizer status compared with that in plants grown under basic fertilizer status. The increase in the activities of SOD, APX and GR in rice leaves by relatively long-term treatment with O3 at low concentration is considered to indicate that the plant became adapted to the O3 stress and the protection system increased its capacity to scavenge toxic oxygen species. Our results in two rice cultivars indicated that there was little difference in the activities of antioxidant enzymes between IL and KM, which were known as resistant and susceptible cultivar to O3