• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.678-684
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• 2012

The purpose of this study is to figure out and establish the basic data that can help improve management of oral healthcare for the international marriage migrantwomen. In this sense, we surveyed questions on 237 women out of 1,300 immigrant women, who have participated the program in operation by multi-cultural household supporting center, in a fashion of face-to-face investigation and on-the-spot direct cavity inspection simultaneously from May 1th to October 31th, 2010. Collected data were electro-statistically computerized under SPSS 17.0 program and analyzed with frequency analysis, recurrence analysis and logistic regression analysis respectively. Foundings were revealed as follows; On the nationality base, show the data in the ratio of 38.8% for Vietnamese, 29.1% for Philippine, 12.2% for Chinese and 6.8% for Japanese respectively. Current oral cavity status shows in the ratio of 60% with carious tooth symptoms, 40% without carious tooth symptom. Philippine women have irregular sets of tooth in many a case. (i.e., in short of numbers of teeth, due to removing individual tooth.) Japanese ladies are indicated to have less irregular sets of tooth, in comparison with that of the other immigrants from overseas. And lastly, high-income immigrant women in general were found having less numbers of unhealthy sets of tooth. Getting older, it appears that decayed tooth symptom is on the tendency of getting less in the field of dentistry circles. Immigrant ladies living with husbands under higher education background usually are found living a life in the less ratio of having toothache. A full-time immigrant housewives, however, are living everyday life in more times of suffering with tooth disease.

• Journal of the Korean Geotechnical Society
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• v.30 no.1
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• pp.27-36
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• 2014

In this study, laboratory test was carried out on uniaxial compressive strength by making 320 specimens in total, which were divided into two groups considering the curing time of 7 and 28 days for 80 cases mixed with stabilizers of 8%, 10%, 12%, 14% of 20 cases of clayey, sandy, and gravel mixed ground conditions to understand laboratory strength characteristics of deep mixing specimen for field application in various ground conditions. As a laboratory result, all specimen showed a clear tendency to have uniaxial compressive strength increase as the curing time and the stabilizer mixing ratio increased, and the strength increments depending on the age by ground types were, around 40.0% for clayey and gravel mixed grounds, 48.4% for sandy grounds which was the highest, and for the increment of stabilizers, around 37.0% for grounds with mixing ratio less then 14%, and 49.6% when the ratio was 14% which was the highest. Also, with sandy grounds, it showed a tendency to have a constant amount of strength increment as the stabilizer mixing ratio increased, for clayey mixed grounds, the strength increment tendency seemed to be similar to gravel mixed grounds. Due to these tendencies, it is concluded that we are able to propose a stabilizer mixing ratio for various ground conditions.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.5
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• pp.476-486
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• 2004

This paper is the second part of the study on the development of a smart active layer (SAL) sensor, which consists of two parts. As mentioned in the first paper, structural health monitoring (SHM) is a new technology that is being increasingly applied at the industrial field as a potential approach to improve cost and convenience of structural inspection. Recently, the development of smart sensor is very active for real application. This study has focused on preparation and application study of SAL sensor which is described with regard to the theory and concept of the SAL sensor in the first paper. In order to detect elastic wave, smart piezoelectric sensor, SAL, is fabricated by using a piezoelectric element, shielding layer and protection layer. This protection layer plays an important role in a patched network of distributed piezoelectric sensor and shielding treatment. Four types of SAL sensor are designed/prepared/tested, and these details will be discussed in the paper In this study, SAL sensor ran be feasibly applied to perform structural health monitoring and to detect damage sources which result in elastic waves.

• Korean Journal of Food Science and Technology
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• v.5 no.2
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• pp.108-112
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• 1973

Zoonoses are very important disease. But little attention has been given to the study of zoonoses in Korea. The author reviewed publications about zoonoses outbreakings in Korea and evaluated and analyzed the data available. It is hoped that the information will be use for reference in future endeavors of study in the field of zoonoses in Korea. The information obtained are as follows: 1) From 1962 to 1966. there have been 3 cases of anthrax. 2 cases of brucellosis and 140 cases of erysipeloid. 2) Throughout Korea, there are 670 slaughther houses and for last ten years cows and swines were condemned by the inspection before slaugter the ranges were as follows: cows : $0.45{\sim}0.98%$ swines : $0.005{\sim}0.05%$ 3) Epidemiological pattern of zoonoses in animals: a) Direct zoonoses are anthrax brucellosis and erysipelos. Encidence rate of anthrax 1.7 per 100,000 in 1964, burcellosis 1338.4 in 1960, erysipelos of swine 1897.2 in 1962. b) It is noticed that $1.0{\sim}2.7%$ of swine in mainland and $3.8{\sim}8.5%$ in Chechu island were infected by cysticercus cellulose.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.5
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• pp.485-492
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• 2009

The thermal fatigue crack(TFC) is one of the life-limiting mechanisms at the nuclear power plant operating conditions. In order to evaluate the structural integrity, various non-destructive test methods such as radiographic test, ultrasonic test and eddy current are used in the industrial field. However, these methods have restrictions that defect detection is possible after the crack growth. For this reason, acoustic emission testing(AET) is becoming one of powerful inspection methods, because AET has an advantage that possible to monitor the structure continuously. Generally, every mechanism that affects the integrity of the structure or equipment is a source of acoustic emission signal. Therefore the noise filtering is one of the major works to the almost AET researchers. In this study, acoustic emission signal was collected from the pipes which were in the successive thermal fatigue cycles. The data were filtered based on the results from previous experiments. Through the data analysis, the signal characteristics to distinguish the effective signal from the noises for the TFC were proven as the waveform difference. The experiment results provide preliminary information for the acoustic emission technique to the continuous monitoring of the structure failure detection.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.103-114
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• 2011

Usage of bicycle has been supported the universal reduction of energy consumption and $CO_2$. For the same purpose, new constructions for long length bike roads are planned in Korea. Recently, laboratory tests of physical properties and resistance against environmental loading about optimum mix design of roller compacted concrete, that have advantages of high structural performance by cement hydration and aggregate interlocking, simple construction procedure and low construction cost, are performed for the effective construction of new bike roads. However, properties of roller compacted concrete had different results between laboratory and field tests since it had different compaction method. Also, construction method of roller compacted concrete are not defined for the application of bike roads since it had different demand performance such as thin pavement thickness, low strength and etc with road pavements. Thus, in this experimental research was launched to evaluate the core properties, visual inspection, compaction ratio, water content, thickness reduction rate of roller compaction, skid resistance and roughness by experimental construction about variable mix proportion and compaction method based on laboratory test results. And construction method of roller compacted concrete pavement were suggested for the application of bike roads.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.4
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• pp.445-449
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• 2005

Present study was designed to evaluate the practical application of triethyl amine(TEA) injection for improving the collection efficiency of electrostatic precipitator(ESP) connected to a real operating plant. The major fuels used at the domestic power stations were bituminous coals imported from Australia, China, South Africa, and USA. Although the values of the electric resistance would be more or less different according to the type of the coals used, the unique electric resistance values of fly ash from the coals were mostly higher than $1{\times}10^{12}\;{\Omega}-cm$ and therefore, back corona problems were always expected to occur in the electrostatic precipitator. The particulates concentrations, smoke concentrations and their electric resistivity measured at the outlet of ESP, and the inspection of collection indicated that the injection of TEA improved the collection efficiency of particulate at collection plates of ESP. The electric resistance for, fly ash with the injection concentration of TEA 15 ppm(Purity 99.7%) was lowered to $2.1{\times}10^{11}\;{\Omega}-cm$ after injection from $1.9{\times}10^{12}\;{\Omega}-cm$ before injection. Under this condition, the dust emission content at the stack was reduced to approximately 80%, lowering the average outlet concentrations of particulates from $70\;mg/Sm^3$ to $14\;mg/Sm^3$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.443-450
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• 2020

This paper reports a design improvement study to solve the stoppage phenomenon caused by the launch-support device applied to K105A1. The K105A1 is a weapon system equipped with an old 105 mm towed howitzer in a wheeled vehicle, which provides superior maneuverability compared to track equipment. The launch support device serves to withstand fire impact and load. In this way, this device is fixed firmly to the ground in preparation for the shooting mission and is responsible for the critical performance, such as fixing the position of the vehicle. On the other hand, during the field test, a temporary stoppage of the launch support occurred, which caused a problem of not being fixed to the ground. To solve this problem, the cause of failure was analyzed by a replay test and parts inspection. In addition, the operating concept, method, and design were analyzed to derive the cause and solve the problem by changing the parts design. Finally, the performance and firing missions were performed normally by applying the changed design to K105A1. The performance stability and reliability of the launch support device were confirmed, which are expected to be of great assistance in the development of military equipment in the future.

• Korean Journal of Cognitive Science
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• v.21 no.2
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• pp.309-338
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• 2010

In this paper, we studied the brain-computer interface (BCI). BCIs help severely disabled people to control external devices by analyzing their brain signals evoked from motor imageries. The findings in the field of neurophysiology revealed that the power of $\beta$(14-26 Hz) and $\mu$(8-12 Hz) rhythms decreases or increases in synchrony of the underlying neuronal populations in the sensorymotor cortex when people imagine the movement of their body parts. These are called Event-Related Desynchronization / Synchronization (ERD/ERS), respectively. We implemented a BCI-based mouse interface system which enabled subjects to control a computer mouse cursor into four different directions (e.g., up, down, left, and right) by analyzing brain signal patterns online. Tongue, foot, left-hand, and right-hand motor imageries were utilized to stimulate a human brain. We used a non-invasive EEG which records brain's spontaneous electrical activity over a short period of time by placing electrodes on the scalp. Because of the nature of the EEG signals, i.e., low amplitude and vulnerability to artifacts and noise, it is hard to analyze and classify brain signals measured by EEG directly. In order to overcome these obstacles, we applied statistical machine-learning techniques. We could achieve high performance in the classification of four motor imageries by employing Common Spatial Pattern (CSP) and Linear Discriminant Analysis (LDA) which transformed input EEG signals into a new coordinate system making the variances among different motor imagery signals maximized for easy classification. From the inspection of the topographies of the results, we could also confirm ERD/ERS appeared at different brain areas for different motor imageries showing the correspondence with the anatomical and neurophysiological knowledge.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.1
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• pp.46-52
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• 2013

After an outbreak of viral disease in an aquafarm, release of virus (es) from infected fish into environmental seawater has been suspected. In the present study, we utilized a negatively charged membrane (HA type) as an efficient method for concentration and detection of fish pathogenic viruses, specifically, megalocytivirus and viral hemorrhagic septicemia virus (VHSV) present in field-collected seawater samples or inoculated into seawater artificially. Positively charged viruses adsorbed onto the negatively charged membrane and were eluted with 1 mM NaOH (pH 10.5) following rinsing with 0.5 mM $H_2SO_4$ (pH 3.0). Megalocytivirus and VHSV particles isolated using anegatively charged HA membrane from seawater inoculated with each virus at a concentration of 10 viral particles/mL were of sufficient quantity to show positive results in atwo-step PCR (or RT two-step PCR); however, despite it being negatively charged, a cellulose acetate (CA) membraneshowed negative results. In quantitative PCR, the detection limits of the HA membrane for megalocytivirus and VHSV in seawater were 1.20E+00 viral particles/mL and 1.22E+01 viralparticles/mL, respectively. The calculated mean recovery yields from 1 L seawater spiked with known concentrations of megalocytivirus and VHSV particles were 28.11% and 23.00%, respectively. The concentrate of a 1-L sample of culturing seawater from the aquatank of flounder suffering from VHSV showed clear positive results in PCR when isolated with an HA, but not a CA, membrane. Thus, viral isolation using an HA membrane is a practical and reliable method for detection of fish pathogenic viruses in seawater.