• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.15 no.4
• /
• pp.13-21
• /
• 2012

도시화, 산업화로 인해 도시는 그 주변지역보다 기온이 높은 도시열섬 현상이 발생하고 있으며 이는 인간 활동에 의한 인공폐열 배출량의 증가에 기인한다. 이러한 인간 활동에 의한 도시기온의 변화는 도심과 농촌지역의 차이로 인한 공간적 변이와 아울러 주중과 주간에 기온 차이가 발생하는 시간적 변이를 포함하고 있으나 도시열섬현상의 공간적 변이에 의한 연구에 비해 시간적 변이에 의한 연구는 많이 수행되고 있지 않다. 본 연구에서는 서울 도심의 주중과 주말의 기온차이를 다년간 관측을 통하여 주중과 주말의 주간 변동의 특성을 파악하여 도시 기온의 시간적 변이를 파악하기 위하여 서울시 강남구를 사례로 2007년 10월 31일부터 2010년 12월 11일까지 약 3년간 관측한 자료를 이용하여 분석한 결과 5개 관측지점 모두 주중(weekday)이 주말보다 $1.6{\sim}1.7^{\circ}C$ 기온이 더 높았으며 이는 주중에 도시 내에서 방출하는 인공폐열의 양이 더 많음을 의미하며 고밀도지역은 냉난방수요가 많아 토지이용에 따라 기온의 차가 크므로 이를 저감시키기 위한 도시 및 조경계획이 필요하다.

• Journal of Korean Society for Atmospheric Environment
• /
• v.19 no.2
• /
• pp.167-177
• /
• 2003

The number size distribution of urban aerosols ranging from 0.02 to 20 ${\mu}{\textrm}{m}$ in diameter was measured by using a scanning mobility particle sizer (SMPS) system and an aerodynamic particle sizer spectrometer (APS) at Seoul from November 30,2001 to January 14, 2002. The gaseous species such as CO, NO, NO$_2$, and $O_3$ were also continuously monitored. The daily average concentration of urban aerosols sorted into three groups (0.02~0.1 ${\mu}{\textrm}{m}$, 0.1~1 ${\mu}{\textrm}{m}$ and 1~10 ${\mu}{\textrm}{m}$) and the typical number, surface, and volume distributions of urban aerosols were discussed in this paper. The weekly variation of aerosol concentration was compared with those of gaseous concentrations. relative humidity, and visibility. The results showed that the particle number concentration seemed to increase in the morning and the number concentration of fine particles less than 1 fm in diameter seemed to increase when the concentrations of CO, NO, and NO$_2$ were high. The number concentration of fine particles was relatively high when the relative humidity was greater than 70％ during the increasing period of relative humidity. The visibility was weakly correlated with the concentration of aerosols ranging 0.1 to 1 ${\mu}{\textrm}{m}$, and the number size distribution for high visibility episode was apparently different from that for low visibility episode.

• Korean Journal of Construction Engineering and Management
• /
• v.10 no.2
• /
• pp.75-83
• /
• 2009

PPC stands for the percentage of weekly assignments completed. It makes it possible to improve the performance of production planning and control systems. Recently, the cases of PPC application have been increasing because PPC is easy to apply to construction site. However, to evaluate the average of PPC or analyze PPC as time passes has some problem ; if PPC is the same, the average it is evaluated equally although there are variabilities in production system. Therefore, In order to evaluate the character of PPC in process of production this paper suggests the method of the evaluating PPC by using coefficient of variability besides PPC measurement.

• Korean Journal of Veterinary Research
• /
• v.44 no.4
• /
• pp.649-653
• /
• 2004

To estimate the source of variance components for some hematological parameters and assess the utility of the conventional population-based reference interval, this study computed index of individuality for blood samples, which were from 13 dogs drawn once weekly for 4 consecutive weeks. Results were subjected to nested analysis of variance. For all parameters measured between-dog variations were greater than within-dog variation. Except for the parameters RBC and MCHC the index of individuality was <1.4. The low reliability coefficient and high index of individuality of ${\leq}0.8$ were found for the majority of hematological parameters. In practical term, the present study indicated that use of hemogram profiles alone in the evaluating clinical state of a single patient should be avoided because of their physiological or natural random variations, and that comparing a single measurement on the blood analytes from an individual dog to the conventional population-based reference range may be too insensitive to detect any significant changes in the blood components of that particular dog. A single measurement may not characterize an individual's average concentration of the parameters even shortterm period.

• Journal of Plant Biotechnology
• /
• v.49 no.3
• /
• pp.187-192
• /
• 2022

The repeated monthly or weekly subculture of plant callus is labor intensive and increases the risk of somaclonal variation from the parental callus line. The most effective method for preserving plant callus is cryopreservation, which involves storage in liquid nitrogen. However, this method cannot be applied to the callus of different plant species in the same manner, so it is difficult to develop a standardized cryopreservation method. In addition, the survival rate of the frozen callus after thawing and the regeneration rate after survival are uncertain. Therefore, it is necessary to develop a method to extend the subculture interval of plant callus in an active state. In this study, active plant calli of various species without freezing was incubated at 15℃ for 4 to 12 weeks without subculture. After 12 weeks, 8 lines of plant callus grew less than 2-fold when cultured at 25℃, but at least 2 times as much when cultured at 15℃. Moreover, total antioxidant activity did not differ significantly between plant callus recovered at 25℃ after culturing at 15℃ or at 25℃. These results show that the subculture interval can be extended at a temperature of 15℃ without need for modified medium composition or additional processes. In addition, positive results in all calli of several plant species are expected to reduce labor as well as somaclonal variation by increasing the subculture.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.52 no.5
• /
• pp.37-45
• /
• 2010

Manure recycling as fertilizer is one of solutions for the environmental problem related with livestock manure treatment as well as the ocean dumping ban act prohibiting manure disposal to the ocean. For the manure disposal, forest area can be a candidate place because the area has a wide range of applicable sites. However, the manure application to the forest has a possibility of causing environmental impacts including water quality problems due to nutrient loading. Therefore it is necessary to investigate water quality impact from manure disposal to the forestry plantation. In this study, ground and soil water quality had been monitored in the bio-circulation experimental forest where low concentration liquid manure (LCLM) was applied. Soil and groundwater samples were collected and analyzed weekly from April to October in 2008 and 2009. The mean and variation of NO3-N concentration in soil water of LCLM treatment places showed higher concentration than the reference places declining during growing season. In the case of groundwater from monitoring well in the downstream of disposal site, the $NO_3$-N concentration was 3.59 mg/L in 2008 and 3.26 mg/L in 2009 in average showing higher concentration than the reference well although the concentration was not exceed the national drinking water standard. To investigate the source of nitrate, $\delta^{15}N$ isotope analysis was also implemented. Its result showed that the LCLM application could be the nitrate source requiring further long-term monitoring soil and water quality.

• Journal of Positioning, Navigation, and Timing
• /
• v.9 no.3
• /
• pp.229-236
• /
• 2020

The trend of water vapor contents in atmosphere is one of key elements for studying climate change. The tropospheric products, i.e., ZTD values achieved through GPS data processing can retrieve the amount of water vapor with higher temporal and spatial resolution than any other instruments. In this study, the tropospheric products of KASINET for a time period from 2001 to 2014 are reprocessed using PPP strategy and the products from the CODE's 2nd reprocessing campaign. For consistency with reprocessing activities of other networks like EPN, the VMF1 mapping function and non-tidal loading effect due to atmospheric pressure are applied in the process. The reprocessing results are investigated through comparing with the CODE's 2nd reprocessing products by including some IGS stations in the process and also calculating weekly coordinate repeatability to see the quality of the processing. After removing outliers based on the variation of averaged formal error, all processed stations have similar variations of formal error about 2 mm which is lower than that of the IGS final product. Comparison results with the CODE's 2nd reprocessing products show that the overall mean difference is found to be -0.28±5.54 mm which is similar level of the previous studies. Finally, the ZTD trends of all KASINET stations are calculated and the averaged trend is achieved as 0.19 mm/yr. However, the trend of each month shows different amounts and directions from -1.26 mm/yr in May to 1.18 mm/yr in August. In conclusion, the reprocessed tropospheric product and applied strategy of this study has enough quality as one of reliable solution for a reference product for Korean Peninsula which is needed to use GPSbased tropospheric product for climate change research.

• Journal of Preventive Medicine and Public Health
• /
• v.25 no.4 s.40
• /
• pp.386-398
• /
• 1992

In order to study the relationship between life-style and serum lipids level in young adults, the author measured the concentration of serum total cholesterol (TC), triglyceride (TG) and high density lipoprotein cholesterol (HDL-C) and investigated age, relative weight, weekly alcohol intake and daily cigarette smoking through questionnaire in 310 male workers aged 20 to 39, in Ulsan area. The results obtained were as follows: 1. In the factors being able to influence serum lipids level there was negative correlation between age and alcohol intake, and the positive correlation between age and relative weight, alcohol intake and relative weight, alcohol intake and smoking with the strongest correlation between alcohol intake and smoking. 2. In univariate analysis, mean total cholesterol concentration were significantly different according to age, smoking and relative weight: mean triglyceride concentration were significantly different according to relative weight only; mean HCL-C concentration were significantly different according to alcohol intake alone. 3. In non-drinkers, HDL-C concentration of smokers were significantly lower than that of non-smokers but triglyceride concentration of smokers were significant higher. And in drinkers, total cholesterol concentration of smokers was significantly higher than that of non-smokers. 4. In multiple regression analysis, significant independent variables were relative weight, age and smoking in the total cholesterol concentration, and relative weight, age and alcohol intake in the triglyceride concentration, and alcohol intake, relative weight and smoking in the HDL-C concentration. By these independent variables, total variation in each dependent variable was explained 7.9%, 17.6% and 7.4% respectively.

• Korean Journal of Environmental Agriculture
• /
• v.17 no.1
• /
• pp.34-38
• /
• 1998

To test a potential salt tolerance in phosphorus (P) efficient plants (T9 and T8), tomato seedlings were hydroponically grown in saline media. The tolerance was evaluated by comparing growth and metabolism against T5, non-P-efficient variety, at different salt concentrations: 0, 1, 5, 10 g/L. Fresh weights (FW) were measured weekly. Dry weight (DW), mineral contents, and stomatal resistance (Rs) were measured at the termination of experiment. At the lower two salt concentrations (0, 1 g/L), no significant difference was observed in terms of FW, DW, and Rs. At 5, 10 g/L of salt concentration, however, significant variation is evident: T9 and T8 outperformed T5. On the other hand, no difference was also in N, P, K, and Na contents at the corresponding salt concentration. These observations together indicate that P-efficient strain can better tolerate to salinity.

• Journal of Veterinary Clinics
• /
• v.22 no.3
• /
• pp.198-201
• /
• 2005

The purpose of this study was to assess intra-individual variations of clinicochemical parameters and calculate critical differences in healthy dogs during long-term periods. To calculate the critical difference of clinicochemical parameters, blood samples from 20 apparently clinically healthy dogs were collected once weekly for eight consecutive weeks. The critical difference was calculated as 9.01 mg/dl for urea, 0.52 mg/dl for creatinine, 0.99 g/dl for total protein, 0.39 g/dl for albumin, and 20.64 mg/dl for glucose. If two consecutive results differ by less than the critical difference value, it can be concluded that the difference is probably due to physiological variation. However, when the difference is greater than the critical value, other factors, either related to progression of the disease or the presence of concurrent disease, are more likely to be involved.