검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 9

        1.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        2.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Two lab-scale trickle-bed type biofilters with a single fungal species (Aspergillus fumigatus, Acidomyces acidophilus, respectively) have been studied to investigate the simultaneous removal of inorganic (hydrogen sulfide) and organic (butyl acetate) compounds. The biofilter with Aspergillus fumigatus treated simultaneously two different compounds with removal capacity of 1,511 mgS/m3/hr and 6,324 mgC/m3/hr; and the biofilter inoculated with Acidomyces acidophilus had the removal capacity of 1,254 mgS/m3/hr and 6,045 mgC/m3/hr. Stable operational performance was observed in both biofilters under an acidic condition of pH 2 to 4. Based on pseudo-first-order removal rates as a function of depth in the biofilter, Aspergillus fumigatus showed a twice faster rate of hydrogen sulfide removal than Acidomyces acidophilus, 15.9% (Aspergillus fumigatus) and 17.9% (Acidomyces acidophilus) of total sulfur removed were oxidized to produce sulfates, and 77.8% (Aspergillus fumigatus) and 79.4% (Acidomyces acidophilus) were accumulated in the form of S0 through the bed in both biofilters, respectively.
        4,000원
        3.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cooling operation characteristics of multi-A/C(air conditioner)s were experimentally investigated for combination of indoor units (A+B, A+C, B+C) and operating conditions (standard, overload, low temperature and low temperature freezing). The operating data and performance of the air conditioner were measured using a multi-calorimeter. We also observed compressor frequency and pressure variations. From the experimental results, it was found that the cooling performance and the operating characteristics depend on operation combination of indoor units, in the case of 2 room simultaneous operation. In the four types of cooling tests, the cooling capacity and COP of the 3 room simultaneous operation and 2 room simultaneous operation were similar. Through this experimental study, data on the simultaneous operation characteristics of 2 room simultaneous operation according to the changes of indoor and outdoor temperature of four kinds were obtained.
        4,000원
        4.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, it was observed through the ability of performing secondary tasks and baseline fetal heart rate how the supply of lavender, peppermint and highly concentrated oxygen (40%) affected distraction due to the performance of secondary tasks in the driving environment. Twelve male university students conducted secondary tasks while driving in the environments (6 in total) mixed and designed with oxygen concentration (21%, 40%) and the condition of odors (Normal, Lavender, Peppermint). The test was proceeded in order of stable state (5mins), driving (5mins), and secondary tasks (1min), and by extracting ECG data from every section by 30secs, the mean value of baseline fetal heart rate was calculated. As a result of analysis, in the ability of performing secondary tasks, a percentage of correct answers showed no difference in oxygen concentration and the condition of odors (p > 0.05). In performance completion time, a percentage of correct answers decreased showing a statistically significant difference in the condition of odors compared with the condition where odors were not provided (p < 0.05). As for baseline fetal heart rate, in the comparison between sections, while performing secondary tasks, it increased showing a significant difference compared with stable state and driving state (p < 0.05). The effect of interaction was observed in oxygen concentration and the condition of odors. When odors were not provided, baseline fetal heart rate decreased in 40% oxygen concentration compared with 21% oxygen concentration (p < 0.05), however, when peppermint was provided, it increased in 40% oxygen concentration compared with 21% oxygen concentration (p < 0.05). In conclusion, the fact that the condition of odors increased the ability of calculation, and when only the highly concentrated oxygen was provided, parasympathetic nerve system was activated, however, when highly concentrated oxygen was provided with peppermint at the same time, sympathetic nervous system (sns) was activated, which had a negative effect on the autonomic nervous system was drawn.
        4,000원
        5.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the effects of the secondary tasks such as sending text message (STM) and searching navigation (SN) on skin conductance level (SCL) and driving performance of relatively aged and high-experienced drivers. The s
        4,000원
        6.
        2011.05 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the effects of the secondary tasks such as sending text message (STM) and searching navigation (SN) on skin conductance level (SCL) during driving. The participants included 29 taxi drivers; 14 males aged 56.7 ± 4.3 with 29.7 ± 7.0 years of driving experiences and 15 females aged 55.5 ± 3.5 with 20.1 ± 5.7 years of driving experiences. All subjects were instructed to keep a certain distance (30m) from the car ahead and a constant speed (80km/h or 100km/h). SCL was measured during driving only and driving with secondary tasks. SCL was more increased during the driving with secondary tasks than driving only. By increasing the driving speed, SCL was increased during the driving with secondary taks. Secondary tasks increased an activation of sympathetic nerve system. However, there were no significant differences in the SCL according to gender.
        3,000원
        7.
        2011.05 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to quantitatively evaluate the effects of the secondary task with unexpected situation during simulated driving using the variable indicating control of vehicle. The subjects were participated 50s people including 15 males with 29.5±6.7 years of driving experiences and 15 females with 20.1±5.6 years of driving experiences. All subjects were instructed to keep a certain distance (30m) from the car ahead and a constant speed (80km/hr or 100km/hr). Sending text message(STM) and Searching navigation(SN) were selected as the secondary task. Experiment consisted of driving alone for 1 minute and driving with secondary task for 1 minute. It was defined driving phase and unexpected situation phase respectively. Medial-lateral coefficient of variation(MLCV) of car movement was analyzed for evaluating lane keeping in this study. In the results, MLCV was increased by 118.3% at 100km/hr. In the case of secondary task, MLCV in STN and in SN were increased by 235.1% and 290.3%, respectively. There was no significant difference between male and female. In case of driving at high-speed and with secondary task, it may be disturbed constant control of the vehicle when unexpected situation appeared suddenly.
        3,000원
        8.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 차량 통제 변인과 동작의 부드러움 변인을 이용하여 동시 과제 수행이 운전 수행 능력에 미치는 영향을 정량적으로 제시하는 것이다. 1~2년의 운전 경력을 가진 피험자 20명이 실험에 참여하였다. 피험자는 동작분석을 위해 상지(shoulder, elbow, wrist) 및 하지(knee, ankle, toe)에 9개의 마커를 부착한 후, 운전 시뮬레이터를 이용하여 80km/hr로 주행하는 선행 차량과 30m의 간격을 유지하며 직선 주행하도록 하였다. 동시과제는 문자 메시지 보내기와 네비게이션 검색으로 선정하였다. 실험 시간은 2분으로 운전 시작 후 1분은 운전만을, 다음 1분은 운전과 동시과제를 함께 실시하도록 하였고, 각각 운전구간과 동시과제구간으로 정의하였다. 차간거리(Anterior-Posterior Coefficient of Variation, APCV) 및 차선이격거리의 분산계수(Medial-Lateral Coefficient of variation, MLCV)와 저크비용함수(Jerk-cost function, JC)를 이용하여 운전 수행 능력을 평가하였다. APCV는 운전구간에 비해 운전 중 네비게이션 검색 시 222.1% 증가하였다. MLCV는 문자 메시지 전송 과제를 수행할 경우, 318.2%, 네비게이션 검색 과제를 수행할 경우 309.4%가 증가하였다. JC는 운전구간에 비해 동시과제 수행 시, 팔꿈치, 무릎, 발목, 발가락에서 유의하게 증가하였고, 하지마커 전체의 평균값은 문자과제 수행 시 218.2%, 네비게이션 과제 수행 시 294.7%가 증가하였다. 운전 중 동시과제의 수행은 JC를 증가시켜 운전자의 동작의 부드러움을 감소시키고, APCV와 MLCV를 증가시켜 차량의 횡적 종적 통제를 어렵게 한다고 결론 내릴 수 있다.
        4,000원
        9.
        2001.02 KCI 등재 서비스 종료(열람 제한)
        The effect of major operating parameters in spray drying sorber(=SDS) for automatic control for the simultaneous removal of acidic and organic gaseous pollutants from solid waste incinerator was performed. The field experiment was carried out in pilot scale test for the quantification of major operating parameters of hydrophilic and the hydrophobic pollutants. The removal efficiencies of SO2 and HCI in the 5wt% slurry condition were being increased with the increase of the stoichiometric ratio which is the molecular ratio of lime to the pollutant concentration, and with the decrease of inflow flue gas temperature in the pilot SDS reactor. The removal efficiency along the height of spray drying sorber was closely related to the temperature profile, and more than 90% of total removal efficiency was achieved in an absorption region. For the removal of acidic gas the optimum operating condition considering the economics and a stable operation is the 5wt% of slurry concentration, 1.2 of stoichiometric ratio and 250℃ of inflow flue gas temperature. For the organic gases of benzene and toluene the removal efficiencies were 20 - 60% which is much lower than that of acidic gas. The best removal efficiency was obtained at 1.5 of stoichiometric ratio and 250℃ of inflow flue gas temperature. The organic's removal efficiency along the height of spray drying sorber was quite different from that of acidic gas, that is, more than 60% of the total removal efficiency for benzene and 90% of the total removal for toluene were achieved in the dried adsorption region, which was formed at the lower or exit part of the reactor.