• Journal of Korean Society for Atmospheric Environment
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• v.29 no.2
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• pp.171-185
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• 2013

Wetland has been known as a major biogenic source of $CH_4$ in globe. In a global scale, the amounts of 55~150 Tg $CH_4$ are released into the atmosphere annually from wetlands; and it accounts for about 21% of total $CH_4$ annual global emission. From August 2010 to August 2011, measurements of major greenhouse gas ($CO_2$, $CH_4$, $N_2O$) emissions were conducted from a freshwater wetland at Kunsan ($35^{\circ}56^{\prime}38.94^{\prime\prime}N$, $126^{\circ}43^{\prime}16.62^{\prime\prime}E$), Korea by using floating closed static chamber method. Flux measurements for these gases from western coastal tidal flat at Seocheon ($36^{\circ}07^{\prime}13.85^{\prime\prime}N$, $126^{\circ}35^{\prime}43.18^{\prime\prime}E$), Korea were managed from July 2011 to February 2012 by using closed static chamber method. The average gas fluxes and ranges from freshwater wetland experiment were $0.155{\pm}0.29\;mg\;m^{-2}\;hr^{-1}$ (-0.054~0.942 $mg\;m^{-2}\;hr^{-1}$) for $CH_4$, $17.30{\pm}73.27\;mg\;m^{-2}\;hr^{-1}$ (-52.44~261.66 $mg\;m^{-2}\;hr^{-1}$) for $CO_2$, and $0.004{\pm}0.01\;mg\;m^{-2}\;hr^{-1}$ (-0.02~0.07 $mg\;m^{-2}\;hr^{-1}$) for $N_2O$, respectively. Monthly base flux measurement results revealed that $CH_4$ fluxes during summer months in high water temperature were significantly high, and at least order of one higher than those during other months. The average fluxes and ranges of these greenhouse gases from tidal flat during the experimental period were $0.002{\pm}0.08\;mg\;m^{-2}\;hr^{-1}$ (-0.16~0.22 $mg\;m^{-2}\;hr^{-1}$) for $CH_4$, $-31.18{\pm}75.33\;mg\;m^{-2}\;hr^{-1}$ (-298.87~101.93 $mg\;m^{-2}\;hr^{-1}$) for $CO_2$, and $0.001{\pm}0.01\;mg\;m^{-2}\;hr^{-1}$ (-0.017~0.03 $mg\;m^{-2}\;hr^{-1}$) for $N_2O$, respectively. Comparing the results of gas emissions from tidal flat to those from freshwater wetland, we found significantly lower emissions from tidal flat based on the experiment. Physicochemical parameters of water and soil at these experimental plots were also sampled and analyzed for understanding their correlation with these gas emissions.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.1
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• pp.40-44
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• 2019

Purpose Glomerular filtration rate (GFR) is an important index for evaluation of renal function, renal disease diagnosis and progress monitoring. Therefore, accurate measurement of GFR is clinically important. Among the factors that affect the GFR result, there have been many discussions on the methods such as the correction of the kidney depth, net syringe count, and the method of setting the ROI. However there has been no consideration of counting in the most basic factors like height and weight measurement. In this study, we investigate how height and weight changes affects the result of GFR and review the importance of standardized body measurements. Materials and Methods Fifty patients who underwent GFR test were randomly sampled and examined for changes in height and body weight within one month. From the normal patients without renal disease to the patients with severely decreased GFR, we applied the GFR formula of Gate with varying height and weight. Results: The result showed variation of the height at maximum three centimeters and six kilograms of weight. The first calculation of GFR was done with fixed height value and control variable as weight. Weight was incremented by one kilogram each time up to six kilograms. The GFR showed increased result with increasing weight. The result of GFR showed ten percent increase with six kilograms of weight increase. On the other hand, when height value was incremented by one centimeter up to three centimeters showed decreased GFR result with fixed weight value. Up to three centimeters of height increase showed two percent of decreased GFR with fixed weight. Conclusion This study showed varying GFR result when height and weight changes. Therefore it is clinically crucial not only to maintain and manage body measuring instrument but also to have a standardized measurement methods to derive accurate measured values and to achieve reproducibility.

• Journal of Animal Science and Technology
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• v.51 no.4
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• pp.329-336
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• 2009

The objective of this study was to investigate the relationship between measurements of color and water-holding capacity (WHC) in pork loin. A total of 419 pork loins were sampled from crossbred (Landrace$\times$Jeju native black pig) F2 pigs at a commercial slaughter house. Meat color measurements (CIE $L^*$, $a^*$, $b^*$), chroma ($C^*$) and hue angle (h) were measured with the Minolta Chromameter and WHC was measured by filter paper fluid, drip loss and cooking loss. Also pH, moisture content and crude fat content were measured at 24 hr postmortem. CIE $L^*$, $b^*$ and h values had positive correlation with drip loss (r=0.52, 0.42), but CIE $a^*$ and $C^*$ values were not related to drip loss. Results showed that CIE $L^*$, $b^*$, and h color system was better than CIE $L^*$, $a^*$, $b^*$ color system to predict WHC, especially drip loss. pH was negatively correlated to drip loss (-0.42) and CIE $L^*$ (-0.67). Although CIE $L^*$ and pH were correlated to drip loss, the accuracy of their estimates for drip loss was 27% and 17%, respectively. Consequently, it was confirmed that meat color and WHC were not perfectly related and suggested that CIE $L^*$, $b^*$, and h color space should not be used independently to predict WHC of pork loin.

• The Journal of the Korean Society for Microbiology
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• v.21 no.4
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• pp.487-501
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• 1986

Previous studies from our laboratory suggested that Korean LJP patients might habor A. actinomycetemcomitans of different serotype from Caucasian LJP patients in whom serotype b was predominant. In order to observe the prevalence and serotype distribution of A. actinomycetemcomitans in localized juvenile periodontitis patients and to evaluate leukotoxic activity of oral isolates, this study was performed. A. actinomycetemcomitans was isolated by using a selective medium(tryptic soy agar supplemented with 10% serum, $75{\mu}g$ of bacitracin and $5{\mu}g$ of vancomycin per ml). Using immunoabsorbed, ammonium sulfate-fractionated serotype-specific antisera, a total of 69 strains were serologically categorized by ELISA. Leukotoxicity was monitored biochemically by measuring lactate dehydrogenase indicator of cell viability in culture supernatant of PMNL plus viable A. actinomycetemcomitans mixture. The results were as follows: 1. A. actinomycetemcomitans was detected in 75% of 16 LJP patients, and 71% in the LJP lesions and 6% in the control sites. 2. Presence or absence of A. actinomycetemcomitans in the sampled disease sites has no in fluence on clinical measurements. 3. Three serotypes were approximately equally distributed in overall 9 patients. Three patients harbored 2 different serotypes of A. actinomycetemcomitans in the same disease site or different disease sites. 4. The proportion of leukotoxic oral isolates was 22% of a total of 46 strains and the prevalence was 69% in 13 sampled sites. The same disease site could harbor both leukotoxic and nonleukotoxic strains. 5. Distribution of leukotoxic strains in 3 serotypes were not different.

• Journal of Fashion Business
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• v.13 no.6
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• pp.61-75
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• 2009

The objective of this research is to the enhance the color function of work clothing : to research and analyze the hue and tone of work clothing colors to be used for machinery and heavy industries in national industrial complexes, Through this research, the color using problems which related with safety workers will be revealed. For this project, total 42 sets of work suits were sampled from 12 different companies in the machinery and construction industries in the national industrial complexes of Gyeongsang Namdo Province and 16 sets of work suits currently being sold in the market. The collected work suits samples were classified according to item types and design. Color measurements were taken thus: After calibration according to ASTM D1729 specifications of standardized configuration settings to match standardized luminous source D65(Daylight 6500K) in color cabinet BOTECK SuperLight-VI, the RGB values of the work suits were calculated using PANTONE Color Cue TX. The RGB values of the colors thus derived were converted into V/C values using the Munsell Conversion 9.0.6 and analyzed with Munsell's 10-color system and PCCS. The results were presented according to Munsell's color wheel and color and brightness distributions were expressed in table form, as well as presented as a tone map. Following analysis, color hue distribution was found to be concentrated around PB, and brightness distribution toward the low end and mid range of the scale. Saturation values were distributed mostly around the low end of the scale. Following color tone analysis according to PCCS, it became apparent that colors were mainly distributed around dkg, ltg, and g, at low- and mid-brightness and low-saturation. Therefore, it may be concluded that colors used in work suits in the machinery and heavy industries are mainly cool colors, at low- and mid-brightness and low saturation. It is conjectured that such colors were applied uniformly in the workplace in order to serve certain functions, such as concealment of stains and contamination. Therefore, it follows that the utilization of colors, among other functions served by working clothings, must be taken into consideration in order to enhance safety and efficiency.

• Journal of Biomedical Engineering Research
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• v.33 no.2
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• pp.72-77
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• 2012

Phase Contrast MR Angiography(PC MRA) is excellent MRA technique for measuring the velocity of vessels in the human body. PC MRA need to at least four images for angiogram reconstruction and it caused longer scan time. Therefore, we used keyhole imaging combined PC MRA to reduce the scan time. However, keyhole imaging can lead the erroneous effects as loss of phase information or frequency discontinuous. In this study, we applied the keyhole imaging combined 2D PC MRA for improving the temporal resolution and also measured the velocity to evaluate the accuracy of phase information. We used 0.32T MRI scanner(Magfinder II, Scimedix, Korea). Using the 2D PC MRA pulse sequence, the vascular images for a human brain targeted on the Superior Sagittal Sinus(SSS) were obtained. We applied tukey window function for keyhole images to minimize the ringing artifact and erroneous factors that are induced frequency discontinuous and phase information loss. We also applied zero-padded algorithm to peripheral missing k-space lines to compare keyhole imaging results and the artifact power(AP) value was measured on the complex difference images to validate the image quality. Consider as based on our results, heavy image distortions and artifacts were shown until using at least 50% keyhole factor. Using above the 50% keyhole factors are shown well reconstructed and matched for magnitude images and velocity information measurements. In conclusion, we confirmed the image quality and velocity information of keyhole technique combined 2D PC MRA. Especially, measured velocity information through the keyhole imaging combination was similar to the velocity information of full sampled k-space image despite of frequency discontinuous and phase information loss in the keyhole imaging reconstruction process. Consequently, the keyhole imaging combined 2D PC MRA will give some clinical usefulness and advantages as improving the temporal resolution and measuring the velocity information via selecting the appropriate keyhole factor at low tesla MRI system.

• The Journal of Korean Society for Radiation Therapy
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• v.28 no.1
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• pp.27-34
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• 2016

Purpose : Retrospective evaluation of setup changes using the corrected position during helical tomotherapy Materials and Methods : Head and neck cancer patients were randomly sampled and summarized into 3 groups: Group 1(32) Brain, Group 2 2(28)Maxillar, Nasal cavity, Group 3 (35) Nasopharynx(NPX), Tongue, Tonsil, and Oropharynx(OPX). In 3 groups, the statistical tests based on repeated measurements among 30 times of the duration of treatment by applying X, Y, Z axis errors, roll, weight changes, and vectors as variables. Results : The statistical test results showed that there was no difference between x-axis (p = 0.458) and y-axis (p=0.986) and in roll (p = 0.037), weight change (p <0.001), and the vector (p <0.001). In addition, the pattern between the three groups based on the fraction revealed no difference in x-axis (p = 0.430) and roll (p = 0.299) but a difference in y-axis (.023), weight change (p = 0.001), and vector (p = 0.028). Conclusion : The results of the retrospective evaluation found the change in the group 3 with respect Y, Z, weight, and vector and a larger random error during the treatment including low neck.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.1
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• pp.56-62
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• 2009

In this paper we investigate an analytical approach for noise properties and geometric structure in Computed Radiography(CR) images of industrial steel-tubes. Over thirty diverse radiographic images are sampled from industrial radiography measurements according to radiation intensity. Each image consists of three regions; background, thickness and inner-tube. Among these the region of inner-tube is selected for the object of analysis. Geometric structure which includes the noise generation is analyzed by the statistical and functional methodology. The analysis is carried on spacially and line by line. It verifies the geometrical transfigure from the circle configuration of steel-tube and noise variation. The estimation of fitting function and its error are the geometric factors. The statistics such as standard deviation, mean and signal-to-noise ratio are noise parameters for discrimination. These factors are considered under the intensity variation which is the penetrative strength of radiation. The analysing results show that the original geometry of circle is preserved in the form of elliptic or short/long diameter circle, and the noise deviation has increased inverse proportional to the radiation intensity.

• Asian Journal of Atmospheric Environment
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• v.9 no.1
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• pp.66-77
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• 2015

In order to survey the seasonal variation of the chemical composition of particulate matter of $2.5{\mu}m$ or less ($PM_{2.5}$), $PM_{2.5}$ was sampled from 8 February 2013 to 31 March 2014 in an industrial area of Chiba Prefecture, Japan. Chemical measurements of the sample included: ionic components ($Na^+$, $NH_4{^+}$, $Ca^{2+}$, $Mg^{2+}$, $K^+$, $Cl^-$, $NO_3{^-}$ and $SO_4{^{2-}}$), carbonaceous components - organic carbon (OC) and elemental carbon (EC), and water-soluble organic carbon (WSOC). Also, secondary organic carbon (SOC) was measured based using the EC tracer method, and char-EC and soot-EC were calculated from the analytical results. The data obtained were interpreted in terms of temporal variation. Of the overall mean value of $PM_{2.5}$ mass concentration obtained during the study period, ionic components, OC and EC accounted for 45.3%, 19.7%, and 8.0%, respectively. $NO_3{^-}$ showed a unique seasonal distribution pattern due to a dependence on temperature and absolute humidity. It was estimated that an approximate temperature of $14^{\circ}C$, and absolute humidity of $7g/m^3$ were critical for the reversible reaction of $NH_4NO_3(p){\leftrightharpoons}NH_3(g)+HNO_3(g)$. The amount of OC and EC contributing to the monthly $PM_{2.5}$ mass concentration was higher in autumn and winter compared to spring and summer. This result could be attributed to the impact of burning biomass, since WSOC and the ratio of char-EC/soot-EC showed a similar pattern during the corresponding period. From the comparison of monthly WSOC/OC values, a maximum ratio of 83% was obtained in August (summer). The WSOC and estimated SOC levels derived from the EC tracer method correlated (R=0.77) in summer. The high occurrence of WSOC during summer was mainly due to the formation of SOC by photochemical reactions. Through long-term observation of $PM_{2.5}$ chemical components, we established that the degree to which the above-mentioned factors influence $PM_{2.5}$ composition, fluctuates with seasonal changes.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.1
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• pp.47-52
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• 2010

Green tobacco sickness (GTS) is known as an occupational disease among tobacco harvesters, and a form of acute nicotine intoxication by the absorption of nicotine through the skin from the wet green tobacco plant. On the assumption that GTS may occur by inhalation as well as absorption of nicotine, we measured the airborne nicotine concentration in tobacco field and the processing room of tobacco leaves. We measured the airborne nicotine concentrations in the tobacco field and processing room between 13 and 30 July 2008. All sampling and analyses of airborne nicotine were conducted according to the manual of analytic methods of NIOSH 2551, and we sampled 2 times at 11 points in the tobacco field by area sampling. The sampling in the processing room of tobacco leaves was conducted at 3 points, and earlymorning dew was collected from the tobacco by wringing the moisture into specimen bottles. The airborne nicotine concentration [geometric mean (geometric standard deviation)] in the tobacco field in the P.M. was higher [49.2 mg/$m^3$ (1.3)] than the A.M. concentration [43.4 mg/$m^3$ (1.4)]. Similarly, the nicotine concentration in the processing room of tobacco leaves was 224.4 mg/$m^3$ (1.2), and the concentration of nicotine in the dew was 64.7 mg/${\ell}$ (1.7). Based on our results, the airborne nicotine concentration in the tobacco field and the processing room of tobacco leaves were 100 and 400 times higher than the occupational recommended values (TLV-TWA of 0.5 mg/$m^3$), respectively. In the future, it is hoped that epidemiologic studies and environmental measurements will be conducted for GTS which occurs by inhalation of nicotine. If GTS is confirmed to occur by inhalation of nicotine, respiratory and dermal protective equipment must be distributed.