• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.551-554
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• 2001

A necessity of remote control robots or various searching robots etc. that accomplish works given instead of human under long distance and extreme environment such as volcano, universe, deep-sea exploration and nuclear power plant etc. is increasing, and so the development and the research regarding these mobile robots are actively progressing. The wheel mobile robot or the track mobile robot have a sufficient energy efficiency under this en, but also have a lot of limits to accomplish works given which are caused from the restriction of mobile ability. Therefore, recently many researches for the walking robot with superior mobility and energy efficiency on the terrain, which is uneven or where obstacles, inclination and stairways exist, have been doing. The research for these walking robots is separated into fields of mechanism and control system, gait research, circumference environment and system condition recognition etc. greatly. It is a research field that the gait research among these is the centralist in actual implementation of walking robot unlike different mobile robots. A research field for gait of walking robot is classified into two parts according to the nature of the stability and the walking speed, static gait or dynamic gait. While the speed of a static gait is lower than that of a dynamic gait, a static gait which moves the robot to maintain a static stability guarantees a superior stability relatively. A dynamic gait, which make the robot walk controlling the instability caused by the gravity during the two leg supporting period and so maintaining the stability of the robot body spontaneously, is suitable for high speed walking but has a relatively low stability and a difficulty in implementation compared with a static gait. The quadruped walking robot has a strong point that can embody these gaits together. In this research, we will develope an autonomous quadruped robot with an asaptibility to the environment by selectry appropriate gait, element such as duty factor, stride, trajectory, etc.

• Journal of Preventive Medicine and Public Health
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• v.43 no.4
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• pp.330-340
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• 2010

Objectives: This study aims to evaluate and explain the socioeconomic inequalities of all-cause mortality after breast cancer surgery in South Korea. Methods: This population based study included all 8868 females who underwent radical mastectomy for breast cancer between January 2002 and June 2003. Follow-up for mortality continued from January 2002 to June 2006. The patients were divided into 4 socioeconomic classes according to their socioeconomic status as defined by the National Health Insurance contribution rate. The relationship between socioeconomic status and all-cause mortality after breast cancer surgery was assessed using the Cox proportional hazards model with adjusting for age, the Charlson’s index score, emergency hospitalization, the type of hospital and the hospital ownership. Results: Those in the lowest socioeconomic status group had a significantly higher hazard ratio of 2.09 (95% CI =1.50 - 2.91) compared with those in the highest socioeconomic group after controlling for all the identifiable confounding variables. For allcause mortality after radical mastectomy, all the other income groups showed significantly higher 3-year mortality rates than did the highest income group. Conclusions: The socioeconomic status of breast cancer patients should be considered as an independent prognostic factor that affects all-cause mortality after radical mastectomy, and this is possibly due to a delayed diagnosis, limited access or minimal treatment leading to higher mortality. This study may provide tangible support to intensify surveillance and treatment for breast cancer among low socioeconomic class women.

• 한국해양학회지
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• v.29 no.3
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• pp.258-268
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• 1994

Nitrogenous new production and regenerated production were measured in the southern part of the Yellow Sea (Hwanghae) using a stable isotope /SUP 15/N nitrate and ammonia between April 25∼30, 1993. Nitrogen production varied between 155 and 688 mg N m/SUP -2/ d/SUP -1/, which belongs to meso to eutrophic area values. This is equivalent to 881∼3909 mg C m/SUP -2/ d/SUP -1/, assuming the Redfield ratio for C:N of 5.7:1 (by weight). the f0ratio which is the fraction of new production from primary production, varied between 0.12 and 0.26, indicating that 74 to 88% of primary production was supported by the regeneration of nutrients within the euphoric zone. This low f0ratio is the characteristics of the oligo- to mesotrophic area. Contrary to the expected, the ambient nutrient concentration was not an important factor for controlling productivity in this area during the study period. The difference in productivity among stations was mainly due to the variations in phytoplankton biomass in different water masses.

• Applied Chemistry for Engineering
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• v.28 no.3
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• pp.286-289
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• 2017

Synthesis of zeolite 4A was carried out to optimize the nanoparticle synthesis process using statistical experimental design method. The zeolite 4A was synthesized by controlling the concentration of the silicon precursor, sodium metasilicate (SMS), and characterized by XRD, SEM and nitrogen adsorption. In particular, the property of zeolite 4A can be determined by XRD analysis. Using the general factor analysis in the design of experiments, we analyzed main effects and interactions according to the reactor, reaction temperature and reaction time. The optimum reaction condition for the synthesis of zeolite 4A crystallinity was using an autoclave for 3 hours at $110^{\circ}C$. Furthermore, the optimal synthesis conditions of zeolite 4A with various crystallinity using Ludox as a silicon precursor were presented of what using both the surface and contour plot.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.11 no.1
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• pp.51-60
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• 2000

Background and Objectives : Quality of life(QOL) is a construct representing physical, mental and social well-being. QOL has been used as a device for measuring the severity of health-related condition and treatment outcomes. As the social welfare system develops, the attention to QOL increases as well. The aims of this study was to examine whether the patients with voice disorder perceived significantly more the effects of voice disorder on QOL than nonpatient group did and if any, identify the sociodemographic risk factors influencing QOL of patients. Materials and Methods : This study asked 113 adults with voice disorders who were enrolled in Voice Clinic in the Department of Otolaryngology, Kangbuk Samsung Hospital between lune 1998 and January 1999 and 111 nonpatients to complete a questionnaire designed to elicit information about the effete of voice disorders on quality of lift. The questionnaire included items concerning sociodemographic areas, voice symptoms, job, effects of voice disorders on QOL domains(work, social, psychological, physical, and communication areas), potential risk factors to exposures, familial and medical history of voice disorders. Results : The sociodemographic characteristics of the patient group are as follows : (1) 75.2% of total patient group were female and the rest were male. (2) Age of total patient group ranged from 20 to 65 years. Hoarseness was the most commonly reported complaints, followed by complaints of high note difficulties during singing and voice fatigue. The patient group perceived effects of voice disorders on the areas of work, social, psychological, physical and communication more adversely than the comparison group did (p＜0.05). QOL impairments were evaluated as a function of age, gender, education, and income, controlling other independent effects. The results were that (1) age was significantly associated with work problems and (2) gender and income were significantly associated with psychological problems. Conclusions : The findings indicated that the patients with voice disorders would perceive markedly adverse effect on all QOL domains, that is, work, social, psychological, physical, communicational areas. Therefore, the results of study suggest that lurker investigations about the nature of voice disorders, the prevention, treatment, and coping strategies are needed in the future.

• The Korean Journal of Food And Nutrition
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• v.29 no.4
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• pp.557-564
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• 2016

This study was performed to develop and evaluate beverage prepared with optimally roasted seoritae to maximize the isoflavone content and antioxidant activities of the beverage. Isoflavone content was maximized at the roasting temperature of $110^{\circ}C$ for 20 min. Both DPPH radical scavenging activity and ABTS radical scavenging activity along with total polyphenol content were highest when seoritae was roasted at $110^{\circ}C$ for 20 min. Western blotting was used to determine the level of nuclear factor of activated T-cells 1(NFATc1) involved in controlling osteoclast differentiation. The results showed that NFATc1 had a concentration-dependent inhibitory effect when the RoS110 (roasted seoritae at $110^{\circ}C$ for 20 min) samples were processed at varying concentrations (10, 50, and $100{\mu}g/mL$). Tea samples were prepared from optimally roasted seoritae by varying brewing times (5~90 min) at $65^{\circ}C$, and tea brewed for 60 min had the highest preference with $65^{\circ}C$ as the preferred temperature for drinking.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6215-6223
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• 2015

Tyrosine phosphorylation plays an important role in regulating human physiological and pathological processes. Functional stabilization of tyrosine phosphorylation largely contributes to the balanced, coordinated regulation of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). Research has revealed PTPs play an important suppressive role in carcinogenesis and progression by reversing oncoprotein functions. Receptor-type protein tyrosine phosphatase O (PTPRO) as one member of the PTPs family has also been identified to have some roles in tumor development. Some reports have shown PTPRO over-expression in tumors can not only inhibit the frequency of tumor cell division and induce tumor cell death, but also suppress migration. However, the tumor-suppression mechanisms are very complex and understanding is incomplete, which in some degree blocks the further development of PTPRO. Hence, in order to resolve this problem, we here have summarized research findings to draw meaningful conclusions. We found tumor-suppression mechanisms of PTPRO to be diverse, such as controlling G0/G1 of the tumor cell proliferation cycle, inhibiting substrate phosphorylation, down-regulating transcription activators and other activities. In clinical anticancer efforts, expression level of PTPRO in tumors can not only serve as a biomarker to monitor the prognosis of patients, but act as an epigenetic biomarker for noninvasive diagnosis. In addition, the re-activation of PTPRO in tumor tissues, not only can induce tumor volume reduction, but also enhance the susceptibility to chemotherapy drugs. So, we can propose that these research findings of PTPRO will not only support new study ideas and directions for other tumor-suppressors, importantly, but also supply a theoretical basis for researching new molecular targeting agents in the future.

• Journal of Industrial Technology
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• v.40 no.1
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• pp.13-18
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• 2020

Lithium-ion batteries have a small volume, light weight and high energy density, maximizing the utilization of mobile devices. It is widely used for various purposes such as electric bicycles and scooters (e-Mobility), mass energy storage (ESS), and electric and hybrid vehicles. To date, lithium-ion batteries have grown to focus on increasing energy density and reducing production costs in line with the required capacity. However, the research and development level of lithium-ion batteries seems to have reached the limit in terms of energy density. In addition, the charging time is an important factor for using lithium-ion batteries. Therefore, it was urgent to develop a high-speed charger to shorten the charging time. In this thesis, a discharger was fabricated to evaluate the capacity and characteristics of Li-ion battery pack which can be used for e-mobility. To achieve this, a smart discharger is designed with a combination of active load, current sensor, and temperature sensor. To carry out this thesis, an active load switching using sensor control circuit, signal processing circuit, and FET was designed and manufactured as hardware with the characteristics of active discharger. And as software for controlling the hardware of the active discharger, a Raspberry Pi control device and a touch screen program were designed. The developed discharger is designed to change the 600W capacity battery in the form of active load.

• Clean Technology
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• v.20 no.3
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• pp.290-297
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• 2014

Batch adsorption studies were carried out for equilibrium, kinetics and thermodynamic parameters for adsorption of coomassi brilliant blue G (CBBG) using activated carbon with varying the operating variables like initial concentration, contact time and temperature. Equilibrium adsorption data were fitted into Langmuir, Freundlich and Dubinin-Radushkevich isotherms. From estimated separation factor of Langmuir and Freundlich, this process could be employed as effective treatment for removal of CBBG. Also from Dubinin-Radushkevich isotherm model, adsorption energy (E) indicated adsorption process is physical adsorption. From kinetic experiments, the adsorption reaction was found to confirm to the pseudo second order model with good correlation. Intraparticle diffusion was rate controlling step. Thermodynamic parameters like change of free energy, enthalpy, and entropy were also calculated to predict the nature of adsorption. The change of enthalpy (406.12 kJ/mol) indicated endothermic nature of the adsorption process. The change of entropy (1.66 kJ/mol K) showed increasing disorder in process. The change of free energy found that the spontaneity of process increased with increasing adsorption temperature.

• Korean Journal of Agricultural Science
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• v.31 no.1
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• pp.45-52
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• 2004

Bakanae Disease is an abnormal plant growth caused by Gibberella fujikuroi. The infected plants several inches taller than normal plants in seedbed and field. To control bakanae disease, we made a seed disinfectant from garlic extract. And we isolated allicin($C_6H_{10}OS_2$) from garlic extract and the content was 0.62%. In order to develop efftive seed disinfectant from Garlic extract, we compared it with three seed disinfectants(benomyl, prochloraz, fludioxonil). Prochloraz, fludioxonil and Garlic wettable powder controlled Bakanae disease of rice very well, while benomyl did not suppress the disease enough. Water temperature was turned to be an important factor for controlling the disease by treating seed disinfectants. It was confirmed that the seed disinfectant from garlic extract can be used as non-toxic agricultural medicines.