• Journal of Korean Ophthalmic Optics Society
• /
• v.7 no.2
• /
• pp.33-39
• /
• 2002

The purpose of this study is to evaluate the effects of continuing work on VDT(video display terminal). Therefore, we examined visual fatigue by a questionnaire and measured frequency of blinking, tear film break-up time(BUT), height of palpebral fissure, visual acuity, refraction with retinoscopy and accommodation before and after two hour long VDT work. For the ocular symptoms, the greatest number was tired eyes accounting for 34%. In the visual symptoms, blurred vision was the highest rate of 83% and in case of systemic symptoms, shoulder pain was 38% marked top ranking but other symptoms were also distributed similar rate. The frequency of blinking during VDT work decreased significantly comparing with the one at rest. The average frequency of blinking is 8/min during VDT work and 22/min at rest. The BUT measured immediately after VDT work decreased much more than in the resting state. The average BUT was 7sec immediately after VDT work and 12sec at rest. The height of palpebral fissure during VDT work increased significantly comparing with the value at rest. The average height of palpebral fissure was 7.69mm at rest and 9.04mm during VDT work. The average visual acuity decreased almost 9.5% from 0.63 to 0.57, but refraction with retinoscopy increased about 0.28D to the direction of myopic shift. The amplitude of accommodation decreased approximately 1.49D from 7.98D to 6.49D and this resulted from the prolongation of near point of accommodation. Near point of convergence also was prolongated from 9.45cm to 10.30cm after VDT work.

• The Korean Journal of Food And Nutrition
• /
• v.25 no.4
• /
• pp.1068-1074
• /
• 2012

Ohmic heating uses electric resistance heat which occurs equally and rapidly inside of food when electrical current is flown into. In other study, we researched about soybean protein's characteristic changes by ohmic heating. Nevertheless treated same temperature, denaturation of soybean protein were accelerated by ohmic heating than conventional heating. In this time, we studied thermal property change of potato starch by ohmic heating besides conventional heating. For this purpose, potato starch was heated at same subgelatinization temperature by ohmic and conventional heating. And thermal properties were tested using DSC. Annealing of starch is heat treatment method that heated at 3~4% below the gelatinization point. DSC analysis results of this study, the $T_o$, $T_p$, $T_c$ of potato starch levels were increased, whereas $T_c{\sim}T_o$ was narrowed. This thermal property changes appear similar to annealing's result. It is thought the results shown in this study, because the heating from below the gelatinization point. 6, 12, 24, 72, and 120 hours heating at $55^{\circ}C$ for potato starch, $T_o$, $T_p$, $T_c$ values continue to increased with heating time increase. The gelatinization temperature of raw potato starch was $65.9^{\circ}C$ and the treated starch by conventional heating at $55^{\circ}C$ for 120 hr was $72^{\circ}C$, ohmic was $76^{\circ}C$. The gelatinization range of conventional (72 hr) was $10^{\circ}C$, ohmic was $8^{\circ}C$. In case of 24 hours heating at 45, 50, 55, 60, $65^{\circ}C$ for potato starch, the result was similar to before. $T_o$, $T_p$, $T_c$ values continue to increased and gelatinization range narrowed with heating temperature increase. In case of conventional heating at $60^{\circ}C$, the results of gelatinization temperature and range were $70.1^{\circ}C$ and $9.1^{\circ}C$. And ohmic were $74.4^{\circ}C$ and $7.5^{\circ}C$. When viewed through the results of the above, the internal structure of starch heated by ohmic heating was found that the shift to a more stable form and to increase the homology of the starch internal structure.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.21 no.2
• /
• pp.147-151
• /
• 2001

An optical fiber sensor is capable of nondestructive measurement of a structure and it has an advantage of the immunity to electromagnetic interference because light is not affected by electromagnetic wave. In addition, if optical fibers are buried in an object like a concrete, this sensor tan analyze defects and physical status of the object without disassembling it. Especially, the fiber Bragg grating sensor is a promising optical fiber sensor capable of nondestructive test of such an object. A fiber Bragg grating has the characteristics of reflecting or blotting light of a specific wavelength. If we apply physical quantity like strain to the fiber Bragg grating, the center wavelength of the reflected light is shifted and then we can find the physical quantity applied to the fiber Bragg grating by measuring the center wavelength shift of the reflected light. The fiber Bragg grating sensor capable ot static and dynamic strain measurement is being used in health-monitoring of buildings, structures, etc. Recently increasing is interest in dynamic strain measurement inevitable to the civil structures such as roads and bridges. In this study we implemented the optical fiber sensor system which can measure dynamic strain at multiple points using Fabry-Perot wavelength demodulation. And we measured the static and dynamic strain using this sensor system with a test structure(cantilever). Measurement results were similar to those obtained with the conventional electrical measurement methods.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.40 no.6
• /
• pp.431-441
• /
• 2003

This paper presents the design of 32 bit microprocessor for a sequence control using a field programmable gate array(FPGA). The microprocessor was designed by a VHDL with top down method, the program memory was separated from the data memory for high speed execution of sequence instructions. Therefore it was possible that sequence instructions could be operated at the same time during the instruction fetch cycle. In order to reduce the instruction decoding time and the interface time of the data memory interface, an instruction code size was implemented by 32 bits. And the real time debug operation was implemented for easeful debugging the designed processor with a single step run, PC break point run, data memory break point run. Also in this designed microprocessor, pulse instructions, step controllers, master controllers, BM and BCD type arithmetic instructions, barrel shift instructions were implemented for sequence logic control. The FPGA was synthesized under a Xilinx's Foundation 4.2i Project Manager using a V600EHQ240 which contains 600,000 gates. Finally simulation and experiment were successfully performed respectively. For showing good performance, the designed microprocessor for the sequence logic control was compared with the H8S/2148 microprocessor which contained many bit instructions for sequence logic control. The designed processor for the sequence logic showed good performance.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.8
• /
• pp.1631-1636
• /
• 2015

With the advance of wireless communication technology in terrestrial area, underwater communication is also evolving very fast from a simple point-to-point transmission to an elaborate networked communications. Underwater acoustic channel has quite different features comparing with the terrestrial radio channel in terms of propagation delay, Doppler shift, multipath, and path loss. Thus, existing technologies developed for terrestrial communication might not work properly in underwater channel. Especially medium access control (MAC) protocols which highly depend on propagation phenomenon should be newly designed for underwater network. CSMA/CA has drawn lots of attention as a candidate of underwater MAC protocol, since it is able to resolve a packet collision and the hidden node problem. However, a received signal could be degraded by the interferences from the nodes locating outside the receiver's propagation radius. In this paper, we study the effects of interference on the CSMA/CA based underwater network. We derived the SNR with the interference using the sonar equation and analyzed the degradation of the RTS/CTS effects. These results are compared with the terrestrial results to understand the differences. Finally we summarized the design considerations in CSMA/CA based underwater network.

• The Journal of Korean Medicine
• /
• v.32 no.2
• /
• pp.92-101
• /
• 2011

Purpose: To evaluate the effects on vision care program including traditional Korean treatment for elementary school students. Methods: 172 eyes of eighty-six older elementary students underwent a vision care program, including traditional Korean treatment, for 3 months between March 2010 and June 2010. The vision care program included health education, such as lifestyle modification, vision strengthening exercises and a course of treatment with traditional Korean methods. Traditional Korean treatment covered periocular acupuncture point stimulation, periauricular acupuncture point stimulation and herbal drug therapy. All patients were examined for visual acuity and auto-refraction and filled out a satisfactory questionnaire about ocular discomforts and quality of life before and after treatments. Results: Patients with mild myopia (-0.75~-2.00) were 61 (35.5%), and 46 (26.7%) were emetropia (${\pm}0.50$ or less). After treatment, uncorrected visual acuity in both eyes was $0.77{\pm}0.46$, which was lower than that before treatment ($0.82{\pm}0.51$), but corrected visual acuity was $0.98{\pm}0.21$, which was higher than that before treatment ($0.93{\pm}0.28 $). About the refractive change, the emetropia group showed a slightly myopic shift while the mild myopia group intended to reduce the myopic error. However, this was not statistically significant. The scales of eyeball pain or discomfort decreased significantly from $17.59{\pm}22.5$ before treatment to $10.28{\pm}17.80$ after treatment, and the scales of the quality of life increased from $1.85{\pm}1.25$ before treatment to $2.25{\pm}1.30$ after treatment. Most patients (90.7%) were satisfied with their treatment results. Conclusions: The vision care program including traditional Korean treatment for elementary school students was effective to improve corrected visual acuity in both eyes and delay the progression of school myopia. In addition, it helped to reduce eyeball pain and discomfort and ultimately to enhance quality of life. Long-term follow-up studies will be needed.

• Journal of Veterinary Clinics
• /
• v.12 no.1
• /
• pp.799-818
• /
• 1995

This study was performed to examine the general anesthetic efficacy of tiletamine-zolazepam, a mixture of phencyclidine-derived tiletamine and benzodiazepine-related zolazepam. The antagonistic activities of doxapram and yohimbine to the anesthetic effects of tiletamine-zolazepam were also studied. Thirty healthy mongrel dogs were divided into three groups (each of 10) twenty minutes after being anesthetized with tiletamine-zolazepam : T-Z-S group(tiletamine-zolazepam-saline), T-Z-D group (tiletamine -zolazepam-doxapram), T-Z-Y group (tiletamine-zolaz.pam-yohim bine). Various parameters wert evaluated in terms of the onset and recovery time of analgesia, respiration rates, hear rates, body temperature, electrocardiogram, blood chemistry, and lymphocyte blastogenesis. The results obtained through these experiment could be summarized as follows: 1. he anesthetic efficacy of tiletamine-zolazepam was considered desirable, with the onset time of anesthesia being as short as 0.23-0.24 minutes. 2. Both of the antagonistic effects of yohimbine and doxapram on the anesthesia induced by liletamine-zolazepan were evaluated statistically significant(p<0.05) as the recovery time was shortened from 39.3$\pm$4.9 min(T-Z-S group) to 25.3$\pm$2.9 nin(T-Z-Y group) and 29.9$\pm$8.8min(T-Z-D group), respectively. 3. Respiration rates were not changed by the treatments of both doxapram and yohimbine, with the only transient increase in the T-Z-D group. The changes in the respiration rate were not observed during the whole time course of the experiment. 4. Yohimbine(T-Z-Y group) increased the heart rate significantly from 30 minutes after the adminstration compared to the T-Z-S group and T-Z-D group (p<0.05). 5. The decreases in th, body temporature were observed from 30 minutes in the T-Z-S group(p<0.05) and 40 minutes in th, T-Z-D group(p<0.05), after the adminstration. On the other hand, there was no hypothermia in the T-Z-Y group. 6. In the all experimental groups of the T-Z-S, T-Z-D and T-Z-Y, there were no specific findings on the electrocardiograph incept slight shift to the tachycardia in all cases. 1. We could not find any differences in the blood chemistry between all experimental groups (T-Z-S, T-Z-D and T-Z-Y). 8. the inhibition of the lymphocyte blastogenesis shown in the T-Z-S with 3 hours decreasing and thereafter restoring to the normal values up to the point 5 hours were not occurred in the T-Z-D and T-Z-Y groups. With the above results, we could conclude that both doxapram and yohimbine can be clinically used as recovery agents towards anesthesia by tiletamine- zolazepam fi:on the efficacy point of view, but yohimbine is more recommendable in this case if considering the recovery time and lymphocyte blastogenesis.

• The Journal of Korean Philosophical History
• /
• no.58
• /
• pp.139-160
• /
• 2018

'Gyeokmulchiji' (格物致知), coming to knowledge based on the investigation of things) is a starting point for any study and politics of Confucianism. Much emphasis was placed on the conception of 'Gyeokchi' as a root of every learning and adminstration in the early Joseon period. As Confucianism established itself as a salient value system of the government, a mighty change and paradigm shift happened in its governmental system which had depended upon Buddhism up to that time. Thus, Confucian statecraft also stood out. Daehakyeonui (大學衍義) was preached as a model of regal learning and politics in the governmental agon, and its conceptual starting point was 'Gyeokchi.' The various interpretations and arguments about this concept shows the process in which Zhu Xi NeoConfucianism was deepened into Neo-Confucianism of Joseon's own. This conception reached the essence of 'Li' beyond the problem of cognitive subject and object, and provided a watershed which divided Giho (畿湖) and Yeongnam (嶺南) schools. Confucian method of study, which incorporates knowledge and practice, has great implications for our times when there are many voices of concern over humanities. The enhancement of universities and humanities is much needed to adjust the direction and pace of scientific technology, which is now entirely left with the logic of market. Accordingly, it is quite urgent for us to examine our object of learning again, which should integrate 'Sugi' (修己, cultivating oneself) with 'Chi-in' (治人, governing others), and knowledge with practice.

• Journal of the Korea Convergence Society
• /
• v.12 no.8
• /
• pp.229-243
• /
• 2021

As systematic information protection and management is recognized as an organization's core value, organizations are pursuing a shift from an individual-centered information management method to an organization-oriented information management method. The Enterprise content management system(ECMS) is a solution that supports document security and information sharing by insiders and is being introduced by many organizations due to recent technological developments. The purpose of this study is to present a method of improving performance through continuous use of the ECMS from the user's point of view and also suggest a method to improve the intention of continuous use through the expansion of the technology acceptance model. This study surveyed the employees of organizations that adopted the ECMS and verified the research hypothesis derived from previous studies through structural equation modeling. As a result of the analysis, usefulness, and ease of use affected on the intention of continuous use of the ECMS, and the knowledge sharing culture and the ECMS quality factors affected the technology acceptance model factors. The results of this study have academic and practical significance in terms of suggesting a plan to increase the usability of the ECMS from the user's point of view.

• International Journal of Oral Biology
• /
• v.48 no.2
• /
• pp.9-18
• /
• 2023

The rapid detection of bacteria in the oral cavity, its species identification, and bacterial count determination are important to diagnose oral diseases caused by pathogenic bacteria. The existing clinical microbial diagnosis methods are time-consuming as they involve observing patients' samples under a microscope or culturing and confirming bacteria using polymerase chain reaction (PCR) kits, making the process complex. Therefore, it is required to analyze the development status of substances and systems that can rapidly detect and analyze pathogenic microorganisms in the oral cavity. With research advancements, a close relationship between oral and systemic diseases has been identified, making it crucial to identify the changes in the oral cavity bacterial composition. Additionally, an early and accurate diagnosis is essential for better prognosis in periodontal disease. However, most periodontal disease-causing pathogens are anaerobic bacteria, which are difficult to identify using conventional bacterial culture methods. Further, the existing PCR method takes a long time to detect and involves complicated stages. Therefore, to address these challenges, the concept of point-of-care (PoC) has emerged, leading to the study and implementation of various chair-side test methods. This study aims to investigate the different PoC diagnostic methods introduced thus far for identifying pathogenic microorganisms in the oral cavity. These are classified into three categories: 1) microbiological tests, 2) microchemical tests, and 3) genetic tests. The microbiological tests are used to determine the presence or absence of representative causative bacteria of periodontal diseases, such as A. actinomycetemcomitans, P. gingivalis, P. intermedia, and T. denticola. However, the quantitative analysis remains impossible, and detecting pathogens other than the specific ones is challenging. The microchemical tests determine the activity of inflammation or disease by measuring the levels of biomarkers present in the oral cavity. Although this diagnostic method is based on increase in the specific biomarkers proportional to inflammation or disease progression in the oral cavity, its commercialization is limited due to low sensitivity and specificity. The genetic tests are based on the concept that differences in disease vulnerability and treatment response are caused by the patient's DNA predisposition. Specifically, the IL-1 gene is used in such tests. PoC diagnostic methods developed to date serve as supplementary diagnostic methods and tools for patient education, in addition to existing diagnostic methods, although they have limitations in diagnosing oral diseases alone. Research on various PoC test methods that can analyze and manage the oral cavity bacterial composition is expected to become more active, aligning with the shift from treatment-oriented to prevention-oriented approaches in healthcare.