• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.9
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• pp.825-829
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• 2012

The global warming caused the changes of our environment like an increasing tropical night phenomenon in the middle latitude areas. Especially, in Korea, the habitats of tropical Korean blockish cicada have changed from Jeju island located in Southern part of Korea to the whole of Korea because of the increasingly warming weather. The cicadas crying sound have been social problem because the tropical Korean blockish cicadas cry at middle of the night owing to the various outdoor lights. The cicada is positive phototaxis insect. So, the cicada is not cry at night. But if the outdoor light is very bright, then the cicada confuse the night as a day and start to cry. As a result, the cicadas crying noise has caused the resident living in downtown to an unpleasure and sleeplessness. In this research, we have measured three kinds of cicada singing noise at 16 points of urban area(Incheon, Gwangju, Busan, Gyeonggido Anyang). And then we analyzed the sound quality of the three kinds of cicada singing noise using by CADA-X signal process program. And we analyzed the acoustical characteristics by STFT(short time Fourier transform) which is a time-frequency analysis method. The characteristics of the cicada singing noise in terms of the sound quality and the time-frequency variation will be usefull to discover the relations between the human annoyance about the cicada singing noise and the acoustical characteristics.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.12
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• pp.633-638
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• 2015

This study evaluates the capacity of night purging in office buildings to reduce the cooling load. RTS-SAREK is used to estimate the performance of night purging on the steady state. To overcome steady state RTS program limitations, we added unsteady heat transfer equations. When the ACH (Air Change per Hour) increases, the wall temperature decreases in both the steady and unsteady states. The unsteady heat transfer rate is different from the steady transfer rate, which validates the unsteady calculation. When ACH is low, the heat transfer rate increases continuously with time. When ACH becomes higher, the heat transfer rate increases and decreases with time. When ACH is quite high, there exists a large difference in the heat transfer rate between the steady and unsteady calculations, which emphasizes the importance of the unsteady calculation.

• Journal of Navigation and Port Research
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• v.34 no.5
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• pp.305-309
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• 2010

This paper is provided to improve the discrimination of the towing line for tug-barge at the night sailing. As tugboat industry develops, marine accidents by tugboats are increasing. The main cause of accidents by tugboats is operators' negligence, and that portion is over 70 percent in total marine casualties by tugboats. The biggest cause of negligence is the passing through the towing line at night time. This paper suggests the ways to hinder operators' transit and improve discrimination of towing line(s) at night time.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.57
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• pp.1-10
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• 2000

The purpose of this paper is to propose a method of rest to reduce work load of night shift workers for night shift work. The experiment was carried out 10minutes preparing time, 45minutes first work, 10minutes first rest, 45minutes second work, 10minutes second rest between 2 and 4 o'clock that the lowest physiological function of workers. The methods of rest set up as four patterns (1) non-action rest (2) non-action rest + listening music (3) action rest + non-action rest, (4) action rest + non-action rest + listening music. For the measurements of experiment, heart rates(R-R interval), critical flicker fusion frequency(CFF), blood pressure, oral temperature, reaction time and error rates were considered as criteria for work performance. As a result, action rest + non-action rest and action rest + non-action rest + listening music were more effective to reduce work load additional work than non-action rest and non-action rest + listening music.

• Journal of Families and Better Life
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• v.17 no.1
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• pp.1-14
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• 1999

The purpose of this study were to examine relative contribution of personal.family.peer and school variables influencing runaway particularly the first-time rundaway and repeated one and to classify runaway types Runaway was significantly influenced by peer delinquency manic behavior family dysfunction school achievement night school depression family type and abuse by family members. First-time runaway was significantly influenced by peer delinquency family type depression abuse by family members night school Repeated runaway was significantly influenced by peer delinquency family dysfunction school achievement manic behavior and night school. Three runaway types were classified $\ulcorner$runaways from family crisis$\lrcorner$$\ulcorner$runaways dissatisfied with family$\lrcorner$ and $\ulcorner$funseekers$\lrcorner$.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.1
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• pp.35-49
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• 2014

In order to understand the impacts of surface characteristics and the distance from the urban heat island center to suburban areas on the mean night time air temperature, we analyzed GIS and AWS observational data. Spatial distributions of mean night time air temperature during the summer and winter periods of 2004-2011(six years) were utilized. Results show that the temperature gradients were different by distance and direction. We found high correlation between mean night-time air temperature and artificial land cover area within 1km and 200m radii during both summer(R=0.84) and winter(R=0.78) seasons. Regression models either from 1km and 200m land surface data explained the distribution of night-time temperature equally well if the input data had sufficient resolution with detailed attribute including building area and height.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.326-332
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• 2011

The growth and bolting characteristics of spring Chinese cabbage cultivars at two night-time temperature treatments such as $5^{\circ}C$ and $10^{\circ}C$ during seedling stage were investigated to establish a safe environmental management strategy for raising seedlings. The low night-time temperature treatments were applied at 5, 10, and 15 days after sawing and the treatment durations were 5, 10, and 15 days in each of treatment beginning. The growth of seedlings in all the tested cultivars were linearly reduced as the treatment duration was extended and no symptoms of bolting were found. The reduction rate in seedling growth of 'Chunkwang' reached to 59.3% at most by 15 days of $5^{\circ}C$ treatment when it be compared to that of control. However, no symptoms of bolting were shown in the treatments of two night-time temperatures until the harvest at 90 days after sawing, indicating that the vernalization effect by low night-time temperature could be mitigated by subsequent day-time optimal temperature management. This study showed that the major spring Chinese cabbage cultivars require more ultimate level of low night-time temperature treatment for the vernalization than this study. It is also supposed that the optimal day-time temperature management can reduce or delay the rate of bolting, even if the seedlings were exposed to short-term low temperature below $5^{\circ}C$ during night-time.

• Journal of Environmental Science International
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• v.6 no.6
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• pp.697-709
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• 1997

Sequencing Batch Reactor(SBR) experiments for organics and nutrients removal have been conducted to find an optimum anaerobic/anoxic/aerobic cycling time and evaluate the applicability of oxidation-reduction potential(ORP) as a process control parameter. In this study, a 61 bench-scale plant was used and fed with night-soil wastewater in K city which contained TCODcr : 10, 680 mg/l, TBm : 6, 893 mg/l, $NH_4^+-N$ : 1, 609 mg/l, $PO_4^{3-}-P$ : 602 mg/l on average. The cycling time In SBRs was adjusted at 12 hours and 24 hours, and then certainly included anaerobic, aerobic and inoxic conditions. Also, for each cycling time, we performed 3 series of experiment simultaneously which was set up 10 days, 20 days and 30 days as SRT From the experimental results, the optimum cycling time for biological nutrient removal with nlght-soil wastewater was respctively 3hrs, 5hrs, 3hrs(anaerobic-aerobic-anoxic), Nitrogen removal efficiency was 77.9%, 77.9%, 81.7% for each SRT, respectively. When external carbon source was fed in the anoxic phase, ORP-bending point indicating nitrate break point appeared clearly and nitrogen removal efficiency increased as 96.5%, 97.1%, 98.9%. Phosphate removal efficiency was 59.8%, 64.571, 68.6% for each SRT. Also, we finded the applicability of ORP as a process control parameter in SBRs.

• Korean Parent-Child Health Journal
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• v.3 no.2
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• pp.1-17
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• 2000

The purpose of this study was to recognized the sleep activity patterns of the normal infants in Korea. The subject were 41 normal infants who were below 8 weeks old and were born in Taegu city and Kyungbuk province. The measuring instrument the sleep activity was NCASA translated by the Korean-parent-child Health Academic Association. The data that were collected from April, 18 1999 to January 1, 2000 were analysed by the SPSS 7.5 program. The results of the study was summarized as follow; 1) The mean amount of total sleeping hours per day was decreased from $16.27{\pm}1.96$ hr at the 1st week, to $15.19{\pm}2.39$ hr at the 2nd week, to $13.66{\pm}2.40$ hr at the 3 week but increased to $16.55{\pm}5.77$ hr at the 4-8 week after birth. 2) The mean frequency of feeding was increased to $9.43{\pm}2.79$ times at the 3rd week but decreased to $7.55{\pm}1.23$ times at the 4-8th week after birth. 3) The regularity of day time sleep was decreased from 50.00% to 19.79% and that of night time sleep was increased from 51.79% to 72.92%. 4) The regularity of feeding was increased from 30.42% at the 1st week to 50.07% at the 2nd week but decreased 26.34% at the 4-8th week after birth. 5) The longest period of day time sleep was decreased to $2.39{\pm}0.42$ hr at the 3rd week but increased $2.47{\pm}0.69$ hr at the 4-8th week after birth. The longest period of night time sleep was decreased to $2.58{\pm}0.67$ hr at the 2nd week but increased to $3.00{\pm}1.32$ at the 3rd week and $4.30{\pm}1.16$ hr at the 4-8th week after birth. 6) At the 1st week, the 2nd week, the 3rd week after birth, the frequency of day time feeding was positively correlated with the frequency of night time feeding($R_{1week}=0.948^{**}$, $R_{2week}=0.927^{**}$, $R_{3week}=0.779^{**})$. At the 4-8th week after birth, the frequency of night time feeding was negatively correlated with the amount of night time sleep ($R_{4week-8week}=0.875^{*}$). On the basis of above findings, the following is suggested; It is need a longitudinal and transcultural study which are designed for children's sleep and feeding.

• Journal of Environmental Science International
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• v.17 no.9
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• pp.1053-1068
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• 2008

This study aims to produce fundamental database for Environment Impact Assessment by monitoring vertical structure of the atmosphere due to the mountain valley wind in spring season. For this, we observed surface and upper meteorological elements in Sangin-dong, Daegu using the rawinsonde and automatic weather system(AWS). In Sangin-dong, the weather condition was largely affected by mountains when compared to city center. The air temperature was low during the night time and day break, and similar to that of city center during the day time. Relative humidity also showed similar trend; high during the night time and day break and similar to that of city center during the day time. Solar radiation was higher than the city, and the daily maximum temperature was observed later than the city. The synoptic wind during the measurement period was west wind. But during the day time, the west wind was joined by the prevailing wind to become stronger than the night time. During the night time and daybreak, the impact of mountain wind lowered the overall temperature, showing strong geographical influence. The vertical structure of the atmosphere in Dalbi valley, Sangin-dong had a sharp change in air temperature, relative humidity, potential temperature and equivalent potential temperature when measured at the upper part of the mixing layer height. The mixing depth was formed at maximum 1896m above the ground, and in the night time, the inversion layer was formed by radiational cooling and cold mountain wind.