• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.5
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• pp.28-34
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• 2008

The real-time biomedical signal monitoring is a very important factor to realize the ubiquitous healthcare environment. Most of these devices for monitoring the biomedical information get the PPG signal from the user, and these signals are utilized for monitoring their health. It is inconvenient to get the PPG because the user should wear the finger probe with his finger for measuring the PPG signal. Also it is difficult to get the PPG correctly, because of the motion artifacts from the movement of the user. In this paper, we develop the watch type biomedical signal monitoring system without the finger probe, and propose the new algorithm for reducing the motion artifacts from the PPG signal. We designed the system which gets the PPG from the sensor on the wrist band strip. As compared with the finger probe type, this system we proposed is more affected by the motion artifacts. So to filter this motion artifacts, we propose the new method; the improved PMAF(Periodic Moving Average Filter) method.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.2
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• pp.51-57
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• 2008

Purpose: This study has been conducted to know how the size and position of the circle of least confusion has an influence on the vision for minimization of asthenopia when astigmatism is corrected and appropriated prescription to provided clear vision life. Methods: The method of the study has been worked on 68 students (136 eyes) of man and woman enrolled in university of Gyeong-gi-do aged 20 to 40, who have myopic astigmatism in order to know how the corrected vision changes according to the size and position of the circle of least confusion of astigmatism, the vision has been tested by giving the vision whose astigmatic power of 0.25D and 0.50D was just reduced, low correcting the astigmatic power into 0.50D, and at the same time inserting additionally spherical power -0.25D, all under a condition that the corrected vision after completely corrected astigmatism, and the axis of astigmatism was not changed. Results: The average vision was 1.047 when the astigmatic power was fully corrected, and in low correction of 0.25D, it was 0.914, and in low correction of 0.50, it was 0.772. It has been learned that the bigger the circle of least confusion was the bigger the range of vision reduction and the corrected vision in astigmatism has correlation with the size of the circle of least confusion. It has been examined that the average vision according to position of the circle of least confusion in astigmatism was 1.047 when the astigmatic power was completely corrected and focused on the retina with state of point, and in case that the astigmatic power was 0.50D of state of low correction, that is, the circle of least confusion was focused before retina, it was 0.828, and it was also 0.826 when the astigmatic power is low corrected with 0.50D and the circle of least confusion was focused on the retina. Explained briefly, It has been examined that in case that the state of low correction of the astigmatic power was same, the vision reduction was less in the image of the circle of least confusion focused upon the retina than in the image of its being focused before the retina. Conclusions: In case that the refractive power of cylindrical lens is reduced in test of wearability in astigmatism, there needs surely an adjustment of spherical lens that can place the circle of least confusion on the retina.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.137-147
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• 2008

Statement of problem: Dental implant procedure has been recognized as a very effective treatment to rehabilitate fully or partially edentulous patients. However, mechanical failures such as screw loosening, screw fracture have been still reported frequently. Purpose: The purpose of this study was to evaluate the influence of tungsten carbide/carbon coating, which has superior hardness and frictional wear resistance, on implant-abutment screw loosening of three different joint connections after one million cyclic loading. Material and methods: The values of detorque before and after loading were measured in three different joint connections (Osstem Implant, Korea), one external butt joint, US II implant system and two internal cones, SS II and GS II system. The values of detorque before loading was analyzed by one-way ANOVA, and two-way ANOVA and Scheffe' test were performed for the value of detorque after loading. Results: 1. The values of initial detorque of tungsten carbide/carbon coated Ti alloy screw were smaller those of Ti alloy screw (P<.01), and there were no differences among implant systems in each screw (P>.05). 2. In comparison of loss rate of detorque value after cyclic loading, US II system was greater than SS II and GS II system but there was no difference between SS II and GS II system (P<.01). 3. Loss rates of detorque value after cyclic loading decreased consistently at tungsten carbide/carbon coated Ti alloy screw comparing with Ti alloy screw in all implant systems (P<.01), and there were no differences among three systems in reduction of loss rates by using tungsten carbide/carbon coated Ti alloy screw (P>.05). Conclusion: Tungsten carbide/carbon coating to increase preload with reduction of friction resistance was a effective way to decrease screw loosening by functional loading.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.555-563
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• 2004

The pH of beverages is known to be low and have, therefore, been implicated in the increasing incidence of erosion. Erosion is believed to be the predominant cause of teeth wear in children and young adults, although there will always be a contribution from attrition and abrasion. The aim of the present study was to evaluate the effect of yogurt on the progression of erosive demineralization in human enamel using demineralization model in vitro. In 4 yogurts, available on the market, pH, buffering capacity and the concentrations of calcium, phosphate and fluoride were determined. The buffering effect was determined by titration with NaOH. 50 milliliters of each drink was then titrated with 1M sodium hydroxide, added in 0.5 milliliters increments, until the pH reached about 7. Human deciduous enamel(n=40) samples were divided into four groups and exposed to 80ml of the yogurt for 30,60, 90 and 120min. Enamel surface microhardness(VHN) was examined before and after each exposure. 1. The average PH of fermented milk was 3.77 and this pH value was acidic enough to cause tooth erosion. 2. All of the fermented milks were found to be erosive(p<0.05) 3. The teeth exposed to the fermented milk all showed erosion like lesions and microhardness measurements showed that enamel surface hardness decreased proportionately with increased time of immersion in all tooth specimen groups. 4. After immersion for 30 and 60 minutes, reduction rate of microhardness values was not significantly different between the groups(p>0.05). However, after 90 and 120 minutes, reduction rate of each group was significantly different(p<0.05).

• Journal of the Korean Society of Costume
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• v.37
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• pp.253-273
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• 1998

The culture reflects the ideology of a particular period in time and such values change according to the needs and requests of that time which eventually becomes an important factorin forming the exterior. The clothing is part of a way that composes and expresses the inherent substance of society and culture. Also, the clothing itself manifests the artistic values and behavior of mankind as an external structure maintaining its place as a big part in culture. The purpose of this study are to elucidat the concept of naturalism, which is discussed in many facets in the modern era; I studied the concept as well as the history of naturalism in order to manifest the meaning of clothing in the context of culture and I explained the concept in terms of the modern era. On such ground, I explained the naturalism expressed through clothing and characterized the exter-nal form of clothing. Also, in order to know the stream of naturalism in the modern context, I referred to the Vogue magazine of the 90s, using Delong's ABC method. Naturalism, in the context of modern fashion is a way to express the nostalgia of nature's vi-ability and purity of ecology apart from the artificial and structural appearance that resulted form scientific enhancement and hence, the ecological crisis. Naturalism pursues the soft- ness and comfort of the natural silhouette, color and material of the human body and it can be said that naturalism emphasizes the mix-ture of three substances : human, nature and clothing. The naturalism can be characterized by the factors expressed in clothing as follows. First, the naturalism shown in the form it-self draws the beauty of the bodyline without any reduction nor exaggeration. Without any distorttion of the human bodyline it shown the curve as one moves along, using the soft material. Second, the naturalism shown in color most-ly uses the natural tone with added white color and other color low in intensity and value like the receded colors of the earth that could be compared to the beauty of ecru. Third, the naturalism shown in the material is thin, light and soft in texture. In order to bring out the most natural curve of the human body, the natural fiber becomes the main material, sometimes, using crude materials. Due to the lindustrial improvement, softness and elasticity is added to the natural fibers giving them an important role as materials. Fourth, the naturalism shown in textile depicts the real natural objects in life. According to my study, the personality of naturalism in modern clothing was shown to be most strong in material and then in the order of form, texture and textile. The material com-posed of the natural silhouette and natural fibers were used to make soft color. In form, Paul Poiret made appearance expressing the natural beauty of the human body without the corset ; it continued with the inner lining making the clothing hard but in the 90s, lining-less, extremely exposed clothes and knit wear is used to emphasize the natural beauty of the body. In color and textile, the tendency spok-en above is not as strong but in color, instead of high intensity or value, the usage of neutral colors with added white color or ecru color, ear-th tone is increasing. In textile, the usage of flowers as natural material is seen frequently. As a whole, naturalistic trend in the 90s is increasing and the modern fashion is breaking out from the artificial and architectural form and conforming to a form that can realize the natural beauty of the human body. And the natural color and textile that conforms to such ideas are being used to pursue the human oriented trend that has appeared due to the increase in usage of soft natural fiber. Nowadays, the idea of returning to nature, defying the artificiality, desiring the leisure and psychological abundance that can be explained as naturalistic way of thinking is necessitated in this modern era as long as humans coexist with nature, this tendency will continue in clothing.

• Journal of Fashion Business
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• v.6 no.1
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• pp.137-154
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• 2002

It's not easy to renew old brand of over 50 years history to the tastes of new consumer of our time. Most of national brands that has a history of some 20 years in Korea have strove for continuation and growth of brand to no avails, which can be taken as a good example of current situation. For instance, C company, one of the National brand of US which has a history of 51 years, has made its position secure as a fashion group and based itself on a sound foundation by establishing new marketing strategy and completing successful brand renewal in the process of strategic M&A with Italian company. Those successful marketing strategies are as follows. 1) they regarded both market and consumer oriented marketing activity as company's highest priority strategy and put great emphasis upon concentration on target market and reestablishment of brand image of business casual wear. 2) Setting up and operating planning team composed of merchandizer alone in Milano, they set the direction of plan on the basis of concentrated research on potential item in market according to thorough market research done by buying office in Korea, branch office in Hong Kong and buyer in US prior to blueprint planning for season. 3) Great emphasis was placed on business which focused on intensive presentation of basic key item for apparel career women who are main consumer group in the midium-low prices market in US and on supplementation of size and color. they named this line 'collectibles' and helped their customer develop their own clothes plan without worrying about the change of color and fabric by supporting same fabric and color throughout the year and enabled them to add variation easily by supplementing new trend item. 4) Company set black as a main color that lots of apparel career women find easy to care and to express their own image and presented them with pebble which belongs to navy and beige and added fashion color such as wine and brown etc as season goes by. They constructed basic line in order for their customers to coordinate purchased item with new one or to add them to present collection, and to achieve efficient sale by setting up strategy which allows this cross coordination and changing pattern occasionally. 5) Though basic jacket for 99$, short slim skirt for 49$ are products within midium-low prices range, in the material planning stage aiming at production of item that has both resonable function appealing to consumer and is fashionable, synthetic material had to be used as a main source due to price competitiveness. Despite this situation, considering comfortable sense of fit and refined drape of silhouette that has no sign of cheap material, whole collectible line was divided into two items, which contributed to reduction of cost. In case of material that is composed of triacetate and polyester in 70 to 30 ratio, was used up to 4 million yard, which allowed drastic curtailment of cost accompanied by concentration. In case of 'collectibles' line, using Korean material mainly, C company chose to have their product sewed in Southeast Asian countries where transportation is well developed and both productivity and quality verified by operating global production system which aiming at cutdown of cost through outsourcing production from the country where labor cost is low and getting finished product. Polarization between present consumers telling us that consumers with the mind of middle classes in the past no longer exists between consumers who seek after only fine article of highest quality and wise consumers who are sensible enough to judge bubble on correlation between price and quality. To cope with this change in new consumer mind, apparel makes changing their policy so as to produce item that has reasonable quality and falls within affordable price range anywhere in the world. and they're striving to get out of difficult situation by operating global marketing strategy which stresses separation of planning, production and sale and sensibility of fashion shared worldwide. The marketing strategy of C company can be exemplified as a successful one.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.7
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• pp.492-507
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• 2010

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2009. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of general thermal and fluid flow, fluid machinery and piping, and new and renewable energy. Various topics were covered in the field of general thermal and fluid flow such as an expander, a capillary tube, the flow of micro-channel water blocks, the friction and anti-wear characteristics of nano oils with mixtures of refrigerant oils, etc. Research issues mainly focused on the design of micro-pumps and fans, the heat resistance reliability of axial smoke exhaust fans, and hood systems in the field of fluid machinery and piping. Studies on ground water sources were executed concerning two well type geothermal heat pumps and multi-heat pumps in the field of new and renewable energy. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included the heat transfer in thermoelectric cooling systems, refrigerants, evaporators, dryers, desiccant rotors. In the area of industrial heat exchangers, researches on high temperature ceramic heat exchangers, plate heat exchangers, frosting on fins of heat exchangers were performed. (3) In the field of refrigeration, papers were presented on alternative refrigerants, system improvements, and the utilization of various energy sources. Refrigeration systems with alternative refrigerants such as hydrocarbons, mixed refrigerants, and $CO_2$ were studied. Efforts to improve the performance of refrigeration systems were made applying various ideas of suction line heat exchangers, subcooling bypass lines and gas injection systems. Studies on heat pump systems using unutilized energy sources such as river water, underground water, and waste heat were also reported. (4) Research trend in the field of mechanical building facilities has been found to be mainly focused on field applications rather than performance improvements. In the area of cogeneration systems, papers on energy and economic analysis, LCC analysis and cost estimating were reported. Studies on ventilation and heat recovery systems introduced the effect on fire and smoke control, and energy reduction. Papers on district cooling and heating systems dealt with design capacity evaluation, application plan and field application. Also, the maintenance and management of building service equipments were presented for HVAC systems. (5) In the field of architectural environment, various studies were carried to improve indoor air quality and to analyze the heat load characteristics of buildings by energy simulation. These studies helped to understand the physics related to building load characteristics and to improve the quality of architectural environment where human beings reside in.

• Journal of the Korean Society of Radiology
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• v.9 no.7
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• pp.529-533
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• 2015

VCUG(Voiding Cystourethrography) study is being performed to check urinary reflex symptom from bladder to ureter or kidney in the method of filling the bladder with radiation opaque contrast agent. However, VCUG study have been performed impersonally, patients have to be naked and open their legs and then void. This method is so impersonal that it is immediately needed to improve the way of testing and crete new aid. Therefore, this study through producing underwear for VCUG, analysis and compares the test time of VCUG, patient radiation dose and patient satisfaction. The target of this study was 79 Male and Female patients who visited genitourinary clinic of PNUYH for their VCUG tests AXIUM Iconos R200(Siemens Medical System : Germany) and self-produced plastic underwears made by vinyl and plasic molding machine were used. The 79 patient were divided into two groups : experiment of patient and comparison group of we patient (using aid) in order to compare, testing time, DAP (dose area product) and patient satisfaction. There was time reduction, from 35.3min of comparison group to 27.8min experimentation group by 7.5min decrease. And comparison group of $4566.6{\mu}Gym^2$(DAP) decreased experimental group (using aid) of $3411.9{\mu}Gym^2$ by $1154.7{\mu}Gym^2$. In the case of patients satisfaction study, anxiety had a drop by 3.45 of comparison group to 2.51 experimentation group by 0.94 decrease. in experimental group. And shame had a drop by 4.02 of comparison group to 3.08 experimentation group by 0.94 increase. in experimental group. Difference of the smooth voiding had a drop by 1.90 of comparison group to 2.84 experimentation group by 0.94 increase. in experimental group. In addition satisfaction had a rise by 1.19 in experimental group. There were also other opinions of uncomfortableness on it and troublesome to wear. VCUG is one of the sensitive care required test. Therefore staff and the aid can give patients such comfortable and the aid can consentive on voiding. As a result test time and DAP can be reduced. It is needed to make testing at more comfortable for patients.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.237-246
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• 2015

Purpose: The present study was conducted to reveal the correlation of structural denaturation and decrease of enzyme activity when the antioxidative enzymes, superoxide dismutase (SOD) and catalase (CAT) were repeatedly exposed to UV-B, and further investigate whether the denaturation and inactivation of those enzymes can be effectively blocked by using UV-inhibitory RGP lens. Methods: Each enzyme solution was prepared from the standardized SOD and CAT, and repeatedly exposed to UV-B of 312 nm for 30 minutes, 1 hour and 2 hours a day over 1, 2, 3, 4 and 5 days. Structural denaturation of SOD and CAT induced by repeat UV-B irradiation was confirmed by the electrophoretic analysis, and their enzyme activity was determined by the colorimetric assay using the proper assay kit. At that time, the change in structure and activity of the antioxidant enzymes directly exposed to UV-B was compared to the case that UV-B was blocked by UV-inhibitory RGP lens. Results: SOD exposed repeatedly to UV-B showed the polymerization pattern in the electrophoretic analysis when it repeatedly exposed for 30 min a day, however, the change of its activity was less than 10%. On the other hand, CAT repeatedly exposed to UV-B reduced size and density of the electrophoretic band which indicated a structure denaturation, and its activity was significantly decreased. In the case that the repeat exposure time was longer, CAT activity was completely lost even though some enzyme band occurred in the electrphoretic analysis. In addition, the degeneration of CAT due to UV-B irradiation was inhibited to some extent by using RGP lens with a UV-B blocking of 63.7%, however, it was not completely inhibited. Conclusions: From these results, it was revealed that the structural denaturation of antioxidative enzymes was not perfectly correlated with the reduction in enzyme activity according to the type of enzyme. It is recommended to minimize the exposure time to UV when wearing contact lens, or wear the contact lenses having UV blocking rate of the FDA Class I blocker or the sunglasses having equivalent UV-blocking rate for reducing the damage of antioxidative enzymes induced by UV.

• Korean Journal of Ecology and Environment
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• v.48 no.2
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• pp.95-107
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• 2015

In order to identify long-term trends of water quality parameters in Lake Kyeongpo, Mann-Kendall test, Sen's slope estimator and linear regression were applied on data, with 15 parameters from three different sites and rainfall, monitored once in every two months from March to November during 1998~2013. Seasonal variation analysis only used Mann-Kendall test and Sen's slope estimator. Analysis result showed that salinity, transparency and nutrient variables (total phosphorus, dissolved inorganic phosphorus, total nitrogen, nitrate nitrogen, ammonia nitrogen) were only parameters having statistically significant trend. In linear regression analysis, salinity (surface and bottom layer of all sites) and transparency (only at site 1), were figured out with statistically significant increasing trend, while in non-parametric statistical method, salinity and transparency in all sites (surface, middle, deep) were figured out with statistically significant increasing trend. Water quality parameters showing statistically significant decreasing trends were dissolved oxygen (surface layer of site 1 and bottom layer of sites 2 and 3), total phosphorus (sites 1 and 2), dissolved inorganic phosphorus, total nitrogen, nitrate nitrogen and ammonia nitrogen in the linear regression analysis and, dissolved oxygen (bottom layer of all sites), total phosphorus, dissolved inorganic phosphorus, total nitrogen, nitrate nitrogen and ammonia nitrogen in the non-parametric method. Seasonal trend analysis result showed that salinity, turbidity, transparency and suspended solids in spring, salinity, transparency, nitrate nitrogen and suspended solids in summer and temperature, salinity, transparency and suspended solids in fall were the variables depending on the season with increasing trends. In general, rainfall during the research period showed decreasing trend. The significant reduction trends of nutrients in Lake Kyeongpo were believed to be related to lagoon restoration and water management project run by Gangneung city and under-water wear removal, but further detailed studies are needed to know the exact causes.