• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.3
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• pp.227-235
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• 2012

The void distribution in concrete materials strongly affects its material properties. Therefore, the identification of spatial distribution of void is important to understand and estimate material behavior. To examine and quantify the void distribution inside lightweight aggregates, CT(computed tomography) image is used. 3D lightweight aggregate images are generated by stacking of cross-sectional images from CT. Spatial distribution of void of aggregate along the direction is visualized on the sphere using probability distribution function. Stiffness of lightweight aggregate for the directions is also examined. It is confirmed that direction-based probability distribution and stiffness from CT images are effective in characterizing void distributions of aggregates.

• Korean Journal of Acupuncture
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• v.24 no.1
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• pp.43-58
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• 2007

Objectives : The elicit of DeQi, a composite of sensation including numbness and fullness that develops at the site of acupuncture stimulation, is considered to be clinically essential to establish treatment efficacy. However, there was little studies investigating the relationship between the subjective feeling of acupuncture sensation and acupuncture analgesia, The current study was therefore performed to determine the correlation between the acupuncture sensation scale (ASS) and the degree of acupuncture analgesia. Methods : Ninety-two female subjects were stimulated at LI4 acupoint on non-dominant hand with real (RA) or sham acupuncture (SA). Finger withdrawal latency (FWL) of each group was also measured to evaluate analgesic effect of acupuncture on the noxious heat stimuli on the dominant hand. All subjects were asked to complete seven point-Likert scale ASS developed by Vincent et al. Results : The increase rate of FWL of the RA group was significantly higher than that of the SA group(36.03 ${\pm}$ 4.45% vs 24.50 ${\pm}$ 3.73%). RA stimulation produced significantly higher rating of all the ASS except for dull sensation, compared to SA stimulation. Significant correlations between analgesic effect of RA, but not of SA, and the degree of the ASS, including burning sensation(r=0.349), Intense sensation(r=0.299), pulsating sensation (r=0.335), and stinging sensation (r=0.306) were found. Conclusions : The results of our study indicate that the DeQi sensation are associated with acupuncture analgesia. Our findings suggest that the evocation of DeQi might be useful clinical indicator of acupuncture treatment.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.1 s.109
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• pp.73-81
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• 2005

Stockigt sizing test, which is readily affected by individual tester's bias as well as testing conditions in recognizing red coloration, had to be modified to improve its reliability and reproducibility. The novel testing system with the automatic recognizing program of red coloration was developed with the auxiliary equipments including an automatic liquid dispenser and a specimen shifter. The analysis program used a hue value of a droplet image in recognizing a point of time on red coloration instead of RGB values that are not similar to human perception of color. Hue was more sensitive in recognizing the red coloration of a droplet than the other two factors, Saturation and Value. During the test, the program records the time consumed up to a specific hue value of a droplet on a specimen. Differently from the conventional test, the automatic test could obtain a reliable and reproducible sizing degree with a minor error. Furthermore, the Stockigt sizing degree measured by the automatic system showed great correlations with contact angle and Hercules sizing degree. It means that such great correlations will contribute to the development of an integrated measuring system capable of predicting contact angle, surface tension, surface energy and Hercules sizing degree of paper and paperboards through the Stbckigt sizing test. It was meaningful to note that the automatic system for Stbckigt sizing test might be able to used to predict contact angle, Hercules and Cobb sizing degree, based upon the high correlation coefficients.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.105-106
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• 2013

Surface plasmon resonance (SPR) is classified into the propagating surface plasmon (PSP) excited on flat metal surfaces and the local surface plasmon (LSP) excited by metalnanoparticles. It is known that fluorescence signals are enhanced by these two SPR-fields.On the other hand, fluorescence is quenched by the energy transfer to metal (FRET). Bothphenomena are controlled by the distance between dyes and metals, and the degree offluorescence enhancement is determined by the correlation. In this study, we determined thecondition to achieve the maximum fluorescence enhancement by adjusting the distance of ametal nanoparticle 2D sheet and a quantum dots 2D sheet by the use of $SiO_2$ spacer layers. The 2D sheets consisting of myristate-capped Ag nanoparticles (AgMy nanosheets) wereprepared at the air-water interface and transferred onto hydrophobized gold thin films basedon the Langmuir-Schaefer (LS) method [1]. The $SiO_2$ sputtered films with different thickness (0~100 nm) were deposited on the AgMy nanosheet as an insulator. TOPO-cappedCdSe/CdZnS/ZnS quantum dots (QDs, ${\lambda}Ex=638nm$) [2] were also transferred onto the $SiO_2$ films by the LS method. The layered structure is schematically shown in Fig. 1. The result of fluorescence measurement is shown in Fig. 2. Without the $SiO_2$ layer, the fluorescence intensity of the layered QD film was lower than that of the original QDs layer, i.e., the quenching by FRET was predominant. When the $SiO_2$ thickness was increased, the fluorescence intensity of the layered QD film was higher than that of the original QDs layer, i.e., the SPR enhancement was predominant. The fluorescence intensity was maximal at the $SiO_2$ thickness of 20 nm, particularly when the LSPR absorption wavelength (${\lambda}=480nm$) was utilized for the excitation. This plasmonic nanosheet can be integrated intogreen or bio-devices as the creation point ofenhanced LSPR field.

• The Journal of Korean Medicine
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• v.30 no.1
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• pp.26-39
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• 2009

Objectives: Pulse energy values recorded with an add-pres sure-type pulse apparatus were correlated with Sasang constitutional syndromes in order to match pulse energy values with Sasang prescriptions. Methods: The pulse energy values were measured with Daeyo Pulse Apparatus at the Gwan pulse point of both wrists. Prescriptions were divided into two major categories of interior syndromes or exterior syndromes, and categorized according to major component herbs specific to each of the four Sasang constitutions, and the relationship between the pulse energy and each groups divided by their prescription was studied. Results: About 10% of all people had nonmal pulse energy values. 10% had values over normal range, and $70\sim80%$ had lower values than normal. The normal range of pulse energy was regarded as being between 450 and 700. Conclusions: 1. For patients of the Soeum constitution, prescriptions without Panax ginseng is suitable for patients with high pulse energy, and prescriptions containing Panax ginseng are suitable for patients who have lower pulse energy. 2. All prescriptions for the Soyang constitution containing Rehmannia radix preparata or Comus officinalis are suitable for patients who have lower pulse energy, and prescriptions containing Rehmannia radix or Gypsum fibrosum are applicable to patients with pulse energy values higher than normal. 3. Most prescriptions for the Taeum constitution containing Semen coicis or Semen castaneae are suitable for patients with lower pulse energy, and prescriptions containing Radix puerariae or Radix et rhizoma rhei can be prescribed for patients who have lower pulse energy levels. 4. The Taeyang constitutional prescription Ogapijangcuck-tang is suitable for patients who have higher pulse energy levels and Mihudeungsikjang-tang is better for patients with lower than normal pulse values. As described above, the pulse energy level of each patient can be matched with a specific Sasang constitutional prescription. If this relationship is taken into consideration with other conventional symptoms, it can be helpful in diagnosis, improving efficacy of treatment, and be used as objective evidence.

• Journal of Welding and Joining
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• v.34 no.6
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• pp.42-46
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• 2016

Hydrogen assisted cracking (HAC) is one of the most complicated problem in welding. Huge amount of studies have been done for decades. Based on them, various standards have been established to avoid HAC. But it is still a chronic problem in industrial field. It is well known that the main causes of the hydrogen crack are residual stress, crack susceptible micro structures and a certain critical level of hydrogen concentration. Even though the exact generating mechanism is unclear till today, it has been reported that the hydrogen level in the weld metal should be managed less than a certain amount to prevent it. Matsuda studied that the residual hydrogen level in the weld metal can be varied even if the initial hydrogen content is same. It is also insisted in this report that the residual hydrogen concentration is in stronger correlation with hydrogen crack than the initial hydrogen content. But, in practical point of view, the residual hydrogen is still hard to consider because measuring hydrogen level is time and cost consuming process. In this regard, numerical analysis is the only solution for considering the residual hydrogen content. Meanwhile, Takahashi showed the possibility of predicting the residual hydrogen by a rigorous FE analysis. But, few commercial software suitable for solving the weld metal hydrogen has been reported yet. In this study, two dimensional thermal - hydrogen coupled analysis was developed by using the commercial FE software MARC. Since the governing equation of the hydrogen diffusion is similar to the heat transfer, it is shown that the heat transfer FE analysis in association with hydrogen diffusion property can be used for hydrogen diffusion analysis. A series of simulation was performed to verify the accuracy of the model. For BOP (Bead-On-Plate) and the multi-pass butt welding simulations, remaining hydrogen contents in the weld metal is well matched with measurements which are referred from Kim and Masamitsu.

• Journal of Environmental Health Sciences
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• v.30 no.2
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• pp.173-183
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• 2004

The purpose of the present study was to assess food hygiene and safety knowledge, attitudes, and practices of food-service personnel in school food-service programs and to find factors affecting their knowledge, attitudes, and practices. A self-administered questionnaire was offered to a random sample of 40 kitchen employees in elementary schools in one region of Korea, with 37 completing the survey, a response rate of 92.5%. The survey was carried out over a two-month period (April-May, 2001). Knowledge score of the employees was high with a mean/standard deviation of 4.75/0.32 on a 5.0-point scale. They had significantly lower attitude score (4.55$\pm$0.33) and practice score (4.55$\pm$0.45) compared to the score of knowledge (p＜0.05). Logistic regression analysis showed that (1) the employees＇ education level and work experience in school food-service programs affected their knowledge, (2) age, level of living, monthly income, and housing type affected their attitudes, and (3) monthly income, level of living, housing type, and work experience in school food-service programs affected their practices. Pearson＇s correlation analysis confirmed that the knowledge and attitude scores were significantly correlated (r=0.598, p＜0.001). The results indicate that the knowledge, attitude, and practice levels of the employees regarding the food hygiene and safety were better than expected, however, the results suggest a need for the adoption of approaches which take account of socio-economic and environmental influences on behavior to improve and maintain their practice level. The food-handling practices of school food-service employees need to be monitored routinely in order to ensure that safe food is served to our school children.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.63.2-63.2
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• 2014

As a part of the "Dust, Ice, and Gas In Time" (DIGIT) key program on Herschel, we observed GSS30-IRS1, a Class I protostar located in Ophiuchus (d =125 pc), with Herschel/Photodetector Array Camera and Spectrometer (PACS). More than 70 lines were detected within a wavelength range from 50 ${\mu}m$ to 200 ${\mu}m$: CO lines from J = 14-13 to 41-40, several $H_2O$ lines of Eup = 100 K to 1500 K, 16 transitions of OH rotational lines, and two atomic [O I] lines at 63 and 145 ${\mu}m$. The [C II] line, known as a tracer of externally heated gas by the interstellar radiation field, is also detected at 158 ${\mu}m$. All lines, except [O I] and [C II], are detected only at the central spaxel of $9^{\prime\prime}.4{\times}9^{\prime\prime}.4$. The [O I] emission is extended along a NE-SW orientation, which is consistent with the known outflow direction, while the [C II] line is detected over all spaxels. One possible explanation of the detection of the [C II] line and no correlation of its spatial distribution with any other molecular emission is the existence of the enhanced ISRF nearby GSS30-IRS1. One interesting feature of GSS30-IRS1 is that the continuum emission is extended beyond the point-spread function (PSF), unlike the molecular line emission, indicative of significant external heating. The best-fit continuum model of GSS30-IRS1 with the physical structure including flared disk, envelope, and outflow shows that the internal luminosity is 11 $L_{\odot}$, and the region is also externally heated by a radiation field enhanced by a factor of 25 compared to the local standard interstellar field.

• Toxicological Research
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• v.33 no.4
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• pp.291-297
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• 2017

This study was performed to investigate the dose-response relationship between average daily cadmium dose (ADCD) from rice and the occurrence of urinary cadmium (U-Cd) in individuals eating that rice. This was a retrospective cohort designed to compare populations from two areas with different levels of cadmium contamination. Five-hundred and sixty-seven participants aged 18 years or older were interviewed to estimate their rice intake, and were assessed for U-Cd. The sources of consumed rice were sampled for cadmium measurement, from which the ADCD was estimated. Binary logistic regression was used to examine the association between ADCD and U-Cd (cut-off point at $2{\mu}g/g$ creatinine), and a correlation between them was established. The lowest estimate was $ADCD=0.5{\mu}g/kg\;bw/day$ [odds ratio (OR) = 1.71; with a 95% confidence interval (CI) 1.02-2.87]. For comparison, the relationship in the contaminated area is expressed by $ADCD=0.7{\mu}g/kg\;bw/day$, OR = 1.84; [95 % CI, 1.06-3.19], while no relationship was found in the non-contaminated area, meaning that the highest level at which this relationship does not exist is $ADCD=0.6{\mu}g/kg\;bw/day$ [95% CI, 0.99-2.95]. Rice, as a main staple food, is the most likely source of dietary cadmium. Abstaining from or limiting rice consumption, therefore, will increase the likelihood of maintaining U-Cd within the normal range. As the recommended maximum ADCD is not to exceed $0.6{\mu}g/kg\;bw/day$, the consumption of rice grown in cadmium-contaminated areas should not be more than 246.8 g/day. However, the exclusion of many edible plants grown in the contaminated area from the analysis might result in an estimated ADCD that does not reflect the true level of cadmium exposure among local people.

• Journal of Korean Neurosurgical Society
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• v.60 no.4
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• pp.465-470
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• 2017

Objective : Magnetic resonance imaging (MRI) grading systems using sagittal images are useful for evaluation of lumbar foraminal stenosis. We evaluated whether such a grading system is useful as a diagnostic tool for surgery. Methods : Between July 2014 and June 2015, 99 consecutive patients underwent unilateral lumbar foraminotomy for lumbar foraminal stenosis. Surgically confirmed foraminal stenosis and the contralateral, asymptomatic neuroforamen were assessed based on a 4-point MRI grading system. Two experienced researchers independently evaluated the MR sagittal images. Interobserver agreement and intraobserver agreement were analyzed using ${\kappa}$ statistics. Results : The mean age of patients (54 women, 45 men) was 62.5 years. A total of 101 levels (202 neuroforamens) were evaluated. MRI grades for operated neuroforamens were as follows : Grade 0 in 0.99%, Grade 1 in 5.28%, Grade 2 in 14.85%, and Grade 3 in 78.88%. Interobserver agreement was moderate for operated neuroforamens (${\kappa}=0.511$) and good for asymptomatic neuroforamens (${\kappa}=0.696$). Intraobserver agreement by reader 1 for operated neuroforamens was good (${\kappa}=0.776$) and that for asymptomatic neuroforamens was very good (${\kappa}=0.831$). In terms of lumbar level, interobserver agreement for L5-S1 (${\kappa}=0.313$, fair) was relatively lower than the other level (${\kappa}=0.804$, very good). Conclusion : MRI grading system for lumbar foraminal stenosis is thought to be useful as a diagnostic tool for surgery in the lumbar spine; however, it is less reliable for symptomatic L5-S1 foraminal stenosis than for other levels. Thus, various clinical factors as well as the MRI grading system are required for surgical decision-making.