• Journal of the Korean Society of Clothing and Textiles
• /
• v.15 no.4 s.40
• /
• pp.431-435
• /
• 1991

The dispersion and Poiar force components of the surface free energy of PET fibers untreated and treated with hydrophilic chemicals, such as nonionic-soil release polymer (SRP), anionic, nonionic and hydrophilic silicone, were determined using harmonic-mean and geometric-mean methods. Contact angles of water and methylene iodide on the fibers were determined from the adhesion tensions using tensiometric method. Fibers treated with hydrophilic chemicals have the increased polar force component and the decreased dispersion force component. The adhesion tensions of triolein for the hydrophilic treated fibers were smaller than that for untreated fiber.

• Journal of Information Processing Systems
• /
• v.14 no.6
• /
• pp.1307-1317
• /
• 2018

To deal with the problems of occlusion, pose variations and illumination changes in the object tracking system, a regression model weighted multi-templates mean-shift (MS) algorithm is proposed in this paper. Target templates and occlusion templates are extracted to compose a multi-templates set. Then, the MS algorithm is applied to the multi-templates set for obtaining the candidate areas. Moreover, a regression model is trained to estimate the Bhattacharyya coefficients between the templates and candidate areas. Finally, the geometric center of the tracked areas is considered as the object's position. The proposed algorithm is evaluated on several classical videos. The experimental results show that the regression model weighted multi-templates MS algorithm can track an object accurately in terms of occlusion, illumination changes and pose variations.

• Journal of Korea Game Society
• /
• v.2 no.2
• /
• pp.28-36
• /
• 2002

In general, triangular meshes have been used for modeling geometric objects such as virtual game characters. The dense meshes give us considerable advantages in representing complex, highly detailed objects, while they are more expensive for storing, transmitting and rendering the objects. Therefore, several researches have been performed for producing a high quality approximation in place of detailed objects, that is, a simplification of triangular meshes. In this paper, we propose a new measure with respect to edges and vertices, which is called an approximate mean curvature and is used as criteria to simplify an original mesh. An edge mean curvature is computed by considering its neighboring edges, and a vertex mean curvature is defined as an average of its incident edges' mean curvatures. And we apply the proposed measure to simplify the models such as a bunny, dragon and teeth. As a result, we can see that the mean curvatures can be used as good criteria for providing much better approximation of models.

• Korean Journal of Ecology and Environment
• /
• v.37 no.1 s.106
• /
• pp.106-111
• /
• 2004

Fecal coliform bacteria is one of the most common cause of water quality impairments in Virginia, USA. Instream concentrations of fecal coliform (FC) bacteria were routinely monitored to assess surface water quality of the Polecat Creek watershed. Median concentration in water samples collected from 1995 to 2000 ranged from 80 cfu/100 mL to t 70 cfu/100 mL, while geometric mean concentrations ranged from 81 cfu/100 mL to 141 cfu/100 mL. The dilution and deposition by Lake Caroline may cause to lower FC concentration at monitoring site QPB, as compared FC concentration at QPD. Higher in-stream FC concentration occurred during the summer period(June-August), and lower concentration typically occurred during the winter period (December-February). This is due to more cattle in streams, and greater survival and regrowth of FC bacteria under warmer condition. The findings of this study can be helpful in planning the water quality monitoring program to avoid the inaccurate assessment of water quality due to the timing of sample collection.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.20 no.4
• /
• pp.274-281
• /
• 2010

The objectives of this study are (a) to investigate the distribution patterns and exposure concentrations of biological agents in sawmill industries and (b) to compare sampling methods of biological agents. The representative processes of 5 sawmills were selected to measure total airborne bacteria, fungi, endotoxin as well as dust. Airborne bacteria and fungi were measured with one stage impactor, six stage impactor and gelatin filteration methods. Endotoxin was collected with polycarbonate filters and analysed by kinetic chromogenic Limulus Amebocyte Lysate method. Geometric mean levels of airborne bacteria, fungi, endotoxin and dust were 1,864 CFU/$m^3$, 2,252 CFU/$m^3$, 31.5 EU/$m^3$ and 2.4 mg/$m^3$. The ratios of indoor/outdoor concentrations were 3.7 for bacteria, 4.1 for fungi, 3.3 for endotoxin and 9.7 for dust. The respiratory fractions of bacteria were 68.0, 50.9, 49.2 and 45.1% in band-saw, table-saw, rip-saw process and outdoor air. The respiratory fractions of fungi were 78.7, 90.8, 87.5 and 84.8% in band-saw, table-saw, rip-saw process and outdoor air, respectively. There was no significant differences in bacterial concentrations among single stage, six stage impaction and filteration methods. But, fungal concentrations measured with filtration methods were significantly higher than those with impaction methods. Geometric mean levels of airborne bacteria and fungi were higher than the OSHA guideline values of 1,000 CFU/$m^3$. The respiratory fractions of fungi were above 75%. The concentrations of biological agents were significantly different among culture-based sampling methods. In the exposure assessments of biological agents, further studies are needed for the comparisons of diverse sampling methods and the investigations of environmental factors.

• Safety and Health at Work
• /
• v.8 no.3
• /
• pp.296-305
• /
• 2017

Background: Surfactant-containing water sprays are commonly used in coal mines to collect dust. This study investigates the dust collection performance of different surfactant types for a range of coal dust particle sizes and charges. Methods: Bituminous coal dust aerosol was generated in a wind tunnel. The charge of the aerosol was either left unaltered, charge-neutralized with a neutralizer, or positively- or negatively-charged using a diffusion charger after the particles were neutralized. An anionic, cationic, or nonionic surfactant spray or a plain water spray was used to remove the particles from the air flow. Some particles were captured while passing through spray section, whereas remaining particles were charge-separated using an electrostatic classifier. Particle size and concentration of the charge-separated particles were measured using an aerodynamic particle sizer. Measurements were made with the spray on and off to calculate overall collection efficiencies (integrated across all charge levels) and efficiencies of particles with specific charge levels. Results: The diameter of the tested coal dust aerosol was $0.89{\mu}m{\pm}1.45$ [geometric $mean{\pm}geometric$ standard deviations (SD)]. Respirable particle mass was collected with $75.5{\pm}5.9%$ ($mean{\pm}SD$) efficiency overall. Collection efficiency was correlated with particle size. Surfactant type significantly impacted collection efficiency: charged particle collection by nonionic surfactant sprays was greater than or equal to collection by other sprays, especially for weakly-charged aerosols. Particle charge strength was significantly correlated with collection efficiency. Conclusion: Surfactant type affects charged particle spray collection efficiency. Nonionic surfactant sprays performed well in coal dust capture in many of the tested conditions.

• Environmental Analysis Health and Toxicology
• /
• v.17 no.2
• /
• pp.109-115
• /
• 2002

This study was conducted to investigate the reference value of mercury (Hg) in liver and kidney of Korean population. The mercury concentration in 244‘sudden and unexpected death’autopsies (male: 180, female: 64) aged from 0 to 87 years was analyzed. The concentration of mercury was measured by atomic absorption spectrophotometer (Perkin-Elmer Model 5100) with mercury/hydride generating system (FIAS 400). The contents of mercury in liver and kidney fitted well the log-normal distribution rather than normal distribution. Geometric mean concentration of mercury in liver and kidney was 0.115 $\mu\textrm{g}$/g wet weight and 0.149 $\mu\textrm{g}$/g wet weight, respectively. Geometric mean concentration of mercury in female was higher than in male (p < 0.01). The mercury content in liver and kidney increased with age up to the forties and slightly decreased there-after. The regression model of mercury deposit in liver and kidney by age was predicted as the following equation : Log LHg : -1.0576＋0.0045$.$Age-0.0001$.$Age$^2$＋0.0873$.$Sex, Log KHg = -1.0576＋0.0152$.$Age-0.0002$.$Age$^2$＋0.1935$.$Sex. The liver burden of mercury was estimated to be 158.3∼161.3 $\mu\textrm{g}$ in male and 163.0∼166.9 $\mu\textrm{g}$ in female. The kidney burden of mercury was estimated to be 42.0∼42.9 $\mu\textrm{g}$ in male and 55.5∼57.1 $\mu\textrm{g}$ in female.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.17 no.1
• /
• pp.71-80
• /
• 2007

The purpose of this study was to assess the ambient level of Polynuclear aromatic hydrocarbons(PAHs), oil mist of the metalworking fluids(MWFs), especially in heat treat industry and non heat treat industry. And we assessed the relationship of the pattern of exposed PAHs with oil mist during survey day. The study population of heat treat industries contained 98 workers, non-heat treat industry contained 40 workers. Personal samples were taken for ambient monitoring of PAHs and oil mist. PAHs was to analyze the relationship of airborne oil mist. The geometric mean of airborne total PAHs was $3.44{\mu}g/m^3$ in heat treat industry and $0.13{\mu}g/m^3$ in non heat treat industry, Pyrene and Benzo(a)pyrene was detected from heat treat industry and Naphthalene in heat treat industry was significantly detected higher than in non heat treat industry. The geometric mean of airborne oil mist was $0.19{\mu}g/m^3$ in heat treat industry and $0.70{\mu}g/m^3$ in non-heat treat industry. The correlation between oil mist and total PAHs was shown below, total PAHs in workers of non heat treat industry and heat treat industry were not significantly correlated with oil mist

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.43 no.1
• /
• pp.25-32
• /
• 2010

A Sanitary survey in an Important shellfish-growing area of Biin Bay in Seocheon-gun Korea, was conducted to evaluate bay conditions and compliance with the bacteriological criteria for areas designated for the production of shellfish for export. Seawater samples were collected monthly at 55 sampling stations established in the survey area from January 2006 to December 2008. Bacteriological water quality did not change in response to a small rainfall (10.0 mm), but it increased abruptly in response to rainfall to 62.5 mm The most probable number (MPN) value for total coliforms and fecal coliforms in 1, 980 seawater samples ranged from <1.8 to >1, 600 MPN/100mL and from <1.8 to 330 MPN/100mL, respectively. The geometric mean and estimated $90^{th}$ percentile value for total coliforms ranged from 2.0 to 10.3 MPN/100mL and from 7.0 to 42.6 MPN/100mL respectively. The geometric mean and estimated percentile value for fecal coliforms ranged from 1.8 to 4.0 MPN/100mL and from 1.9 to 18.3 MPN/100mL, respectively. Accordingly, the bacteriological water quality of Biin Bay met the National Shellfish Sanitation Program (NSSP) and Korea Shel1fish Sanitation Program(KSSP) criteria for areas designated for shellfish production for export in Korea.

• Proceedings of the KAIS Fall Conference
• /
• 2010.11b
• /
• pp.1025-1028
• /
• 2010

The bacteriological examination of spring water in Seogwipo-city was conducted. A total 11 spring water samples were performed from January to April, 2010. During the study period, the range of temperature was from 0.7 to $15.4^{\circ}C$, and result of the analyses showed that hydrogen ion concentrations (pH) for spring water was 0.33 to 7.8. salinity levels for sample average of 0.5 to 1.04‰, as the result of measuring dissolved oxygen (DO) for spring water showed that water dissolved oxygen were 1.02 to 7.14 mg/${\ell}$. The range of total coliform of spring water sample at 11 stations located in the designated spring water were <1.8~>1,600 MPN/100mL. And the range of geometric mean of total coliform were 1.9~117.1 MPN/100mL, The range of fecal coliform of spring water sample at 11 stations located in the designated spring water were <1.8~>1,600 MPN/100mL. And the range of geometric mean of fecal coliform were 1.8~68.1 MPN/100mL, respectively. Level of microbial contamination was examined in 11 samples for indication of bacterial contamination such as heterophic bacteria, EscherichiacoliO157;H7, salmonella spp., Vibrio parahaemolyticus, Staphylococcus aureus, Shigella spp. Were frequently detected from the spring water. Salmonella spp., S.aureus were detected in the range of $0{\sim}1.0{\times}10^1$, $0{\sim}3.0{\times}10^1$ CFU/ml, respectively. And the Escherichia coli O157;H7, Vibrio parahaemolyticus, Shigella spp. Were not detected from the examined spring water samples.