• Progress in Medical Physics
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• v.25 no.4
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• pp.271-280
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• 2014

Recently, digital breast tomosynthesis (DBT) has been investigated to overcome the limitation of conventional mammography for overlapping anatomical structures and high patient dose with cone-beam computed tomography (CBCT). However incomplete sampling due to limited angle leads to interference on the neighboring slices. Many studies have investigated to reduce artifacts such as interference. Moreover, appropriate filters for tomosynthesis have been researched to solve artifacts resulted from incomplete sampling. The primary purpose of this study is finding appropriate filter scheme with FBP reconstruction for DBT system to reduce artifacts. In this study, we investigated characteristics of various filter schemes with simulation and prototype digital breast tomosynthesis under same acquisition parameters and conditions. We evaluated artifacts and noise with profiles and COV (coefficinet of variation) to study characteristic of filter. As a result, the noise with parameter 0.25 of Spectral filter reduced by 10% in comparison to that with only Ramp-lak filter. Because unbalance of information reduced with decreasing B of Slice thickness filter, artifacts caused by incomplete sampling reduced. In conclusion, we confirmed basic characteristics of filter operations and improvement of image quality by appropriate filter scheme. The results of this study can be utilized as base in research and development of DBT system by providing information that is about noise and artifacts depend on various filter schemes.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.5
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• pp.50-60
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• 2010

For the last half a century, the personal computer and software industries have been prosperous due to the incessant evolution of computer systems. In the 21st century, the embedded system market has greatly increased as the market shifted to the mobile gadget field. While a lot of multimedia gadgets such as mobile phone, navigation system, PMP, etc. are pouring into the market, most industrial control systems still rely on 8-bit micro-controllers and simple application software techniques. Unfortunately, the technological barrier which requires additional investment and higher quality manpower to overcome, and the business risks which come from the uncertainty of the market growth and the competitiveness of the resulting products have prevented the companies in the industry from taking advantage of such fancy technologies. However, high performance, low-power and low-cost hardware and software platforms will enable their high-technology products to be developed and recognized by potential clients in the future. This paper presents such a platform for industrial embedded systems. The platform was designed based on Telechips TCC8300 multimedia processor which embedded a variety of parallel hardware for the implementation of multimedia functions. And open-source Embedded Linux, TinyX and GTK+ are used for implementation of GUI to minimize technology costs. In order to estimate the expected performance and power consumption, the performance improvement and the power consumption due to each of enabled hardware sub-systems including YUV2RGB frame converter are measured. An analytic model was devised to check the feasibility of a new application and trade off its performance and power consumption. The validity of the model has been confirmed by implementing a real target system. The cost can be further mitigated by using the hardware parts which are being used for mass production products mostly in the cell-phone market.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.2
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• pp.182-206
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• 2003

Statement of problem : Successful osseointegration of endosseous threaded implants is dependent on many factors. These may include the surface characteristics and gross geometry of implants, the quality and quantity of bone where implants are placed, and the magnitude and direction of stress in functional occlusion. Therefore clinical quantitative measurement of primary stability at placement and functional state of implant may play a role in prediction of possible clinical symptoms and the renovation of implant geometry, types and surface characteristic according to each patients conditions. Ultimately, it may increase success rate of implants. Purpose : Many available non-invasive techniques used for the clinical measurement of implant stability and osseointegration include percussion, radiography, the $Periotest^{(R)}$, Dental Fine $Tester^{(R)}$ and so on. There is, however, relatively little research undertaken to standardize quantitative measurement of stability of implant and osseointegration due to the various clinical applications performed by each individual operator. Therefore, in order to develop non-invasive experimental method to measure stability of implant quantitatively, the resonance frequency analyzer to measure the natural frequency of specific substance was developed in the procedure of this study. Material & method : To test the stability of the resonance frequency analyzer developed in this study, following methods and materials were used : 1) In-vitro study: the implant was placed in both epoxy resin of which physical properties are similar to the bone stiffness of human and fresh cow rib bone specimen. Then the resonance frequency values of them were measured and analyzed. In an attempt to test the reliability of the data gathered with the resonance frequency analyzer, comparative analysis with the data from the Periotest was conducted. 2) In-vivo study: the implants were inserted into the tibiae of 10 New Zealand rabbits and the resonance frequency value of them with connected abutments at healing time are measured immediately after insertion and gauged every 4 weeks for 16 weeks. Results : Results from these studies were such as follows : The same length implants placed in Hot Melt showed the repetitive resonance frequency values. As the length of abutment increased, the resonance frequency value changed significantly (p<0.01). As the thickness of transducer increased in order of 0.5, 1.0 and 2.0 mm, the resonance frequency value significantly increased (p<0.05). The implants placed in PL-2 and epoxy resin with different exposure degree resulted in the increase of resonance frequency value as the exposure degree of implants and the length of abutment decreased. In comparative experiment based on physical properties, as the thickness of transducer increased, the resonance frequency value increased significantly(p<0.01). As the stiffness of substances where implants were placed increased, and the effective length of implants decreased, the resonance frequencies value increased significantly (p<0.05). In the experiment with cow rib bone specimen, the increase of the length of abutment resulted in significant difference between the results from resonance frequency analyzer and the $Periotest^{(R)}$. There was no difference with significant meaning in the comparison based on the direction of measurement between the resonance frequency value and the $Periotest^{(R)}$ value (p<0.05). In-vivo experiment resulted in repetitive patternes of resonance frequency. As the time elapsed, the resonance frequency value increased significantly with the exception of 4th and 8th week (p<0.05). Conclusion : The development of resonance frequency analyzer is an attempt to standardize the quantitative measurement of stability of implant and osseointegration and compensate for the reliability of data from other non-invasive measuring devices It is considered that further research is needed to improve the efficiency of clinical application of resonance frequency analyzer. In addition, further investigation is warranted on the standardized quantitative analysis of the stability of implant.

• Culinary science and hospitality research
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• v.17 no.1
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• pp.124-141
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• 2011

The domestic food culture in Korea has gone through great changes, among which dining out is considered most prominent. These changes are caused by a number of factors: development of several related industries, increase in dining out chances, diversification of consumer needs, change in consumption awareness and quality, increase in disposable income, women's advance into the society, etc. Under these circumstances, the fast food industry has been experiencing slow growth, whereas family restaurants and take out coffee franchises are consistently increasing the number of restaurants and shops as a part of aggressive management to increase sales. This study aims, first, to examine the effects of consumer's brand individuality and satisfaction on brand trust, brand emotion, brand identification, and brand loyalty of specialty coffee shops. Subsequently, this study observes how consumer's brand individuality and satisfaction affect the formation of brand trust, brand emotion, brand identification, and brand loyalty in accordance with preferred type of specialty coffee shops, frequency of experience, and life style in order to establish relevant strategies. The results of this study are as follows. First, brand individuality had a positive effect on customer satisfaction. Second, customer satisfaction had a positive effect on brand trust. Third, customer satisfaction had a positive effect on brand loyalty. Fourth, customer satisfaction had a positive effect on brand emotion. Fifth, brand trust had a positive effect on brand loyalty. Sixth, brand emotion had a positive effect on brand loyalty. These results have the following implications. First, the dimensions of brand individuality are presented as a means to form brand loyalty, thereby demonstrating the significance of the effect. Accordingly, developing a proper brand individuality in forming brand loyalty is imperative. Second, consumers using specialty coffee shops had the greatest effect on the relation between dimensions of brand individuality and customer satisfaction in this study, while the interrelation between customer satisfaction and brand loyalty was not concretely supported in the preceding studies.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.2
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• pp.175-184
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• 2011

With a development of implant restoration technique, there are increasing use of computer-guided system for edentulous patients. It was carried out simulated operation based on CT information about patient's bone quantity, quality and anatomical landmark. However, there are some difference between the programmed implant and post-operative implant about it's position. If the deviation was severe, it could happen a failure of 'passive fit' and not suited for path of implant restoration. The aim of this presentation is to evaluate about a degree of deviations between programmed implant and post-operative implant. Five patients treated by 'NobelGuide' system (Nobel Biocare AB, G$\ddot{o}$teborg, Sweden) in Department of Prosthodontics, Inha University were included in this study. The patients were performed CT radiograph taking and intra-oral impression taking at pre-operation. Based on CT images and study model, surgical stent was produced by NobelBiocareTM. To fabricated a pre-operative study model, after connected lab analog to surgical template, accomplished a pre-operative model using type 4 dental stone. At final impression, a post-operative study model was fabricated in the conventional procedures. Each study model was performed CT radiograph taking. Based on CT images, each implant was simulated in three dimensional position using $Procera^{(R)}$ software (Procera Software Clinical Design Premium, version 1.5; Nobel Biocare AB). In 3D simulated model, length and angulation between each implant of both pre- and post-operative implants were measured and recorded about linear and angular deviation between pre-and post-operative implants. A total of 24 implants were included in this study and 58 inter-implant sites between each implant were measured about linear and angular deviations. In the linear deviation a mean deviation of 0.41 mm (range 0~1.7 mm) was reported. In the angular deviation, a mean deviation was $1.99^{\circ}$ (range $0^{\circ}{\sim}6.7^{\circ}$). It appears that the both linear and angular mean deviation value were well acceptable to application of computer-guided implant system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.1
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• pp.94-131
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• 2007

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2004 and 2005 has been done. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation of facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat, humidity was also interesting for comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing topics. Well developed CFD and flow visualization(PIV, PTV and LDV methods) technologies were widely applied for developing facilities and their systems. (2) The research trends of the previous two yews are surveyed as groups of natural convection, forced convection, electronic cooling, heat transfer enhancement, frosting and defrosting, thermal properties, etc. New research topics introduced include natural convection heat transfer enhancement using nanofluid, supercritical cooling performance or oil miscibility of $CO_2$, enthalpy heat exchanger for heat recovery, heat transfer enhancement in a plate heat exchanger using fluid resonance. (3) The literature for the last two years($2004{\sim}2005$) is reviewed in the areas of heat pump, ice and water storage, cycle analysis and reused energy including geothermal, solar and unused energy). The research on cycle analysis and experiments for $CO_2$ was extensively carried out to replace the Ozone depleting and global warming refrigerants such as HFC and HCFC refrigerants. From the year of 2005, the Gas Engine Heat Pump(GHP) has been paid attention from the viewpoint of the gas cooling application. The heat pipe was focused on the performance improvement by the parametric analysis and the heat recovery applications. The storage systems were studied on the performance enhancement of the storage tank and cost analysis for heating and cooling applications. In the area of unused energy, the hybrid systems were extensively introduced and the life cycle cost analysis(LCCA) for the unused energy systems was also intensively carried out. (4) Recent studies of various refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and of alternative refrigerants including carbon dioxide. Efficiency of various compressors and expansion devices are also dealt with for better modeling and, in particular, performance improvement. Thermoelectric module and cooling systems are analyzed theoretically and experimentally. (5) According to the review of recent studies on ventilation systems, an appropriate ventilation systems including machenical and natural are required to satisfied the level of IAQ. Also, an recent studies on air-conditioning and absorption refrigeration systems, it has mainly focused on distribution and dehumidification of indoor air to improve the performance were carried out. (6) Based on a review of recent studies on indoor environment and building service systems, it is noticed that research issues have mainly focused on optimal thermal comfort, improvement of indoor air Quality and many innovative systems such as air-barrier type perimeter-less system with UFAC, radiant floor heating and cooling system and etc. New approaches are highlighted for improving indoor environmental condition as well as minimizing energy consumption, various activities of building control and operation strategy and energy performance analysis for economic evaluation.

• Journal of Korean Home Economics Education Association
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• v.22 no.1
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• pp.51-65
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• 2010

The purpose of this study was to raise the awareness of LOHAS(Lifestyle of Health and Sustainability) in the secondary school students. We extracted the related contents to LOHAS from the unit of 'The choice and maintenance of clothing' in the second-year's textbook of Technology-Home Economics, and selected the learning subjects. We also developed the new teaching-learning process plan on practical problem focused lesson, and applied them to the eight classes located in Siheung, Gyeonggi-do, for 5 hours per each class. The learning subjects of the teaching-learning process plan included five items as followings; general awareness, organic fashion, natural fabric, recycled material fashion, and natural dyeing, which were related to LOHAS consumption. The overall topic of the teaching-learning process plan was 'What should do to raise the awareness of LOHAS in order to practice LOHAS consumption in the choice of clothing'. Consequently, the results were abtained as follow; The general awareness of LOHAS as well as the awareness of LOHAS consumption in the choice of clothing increased after classes significantly, compared to those before. Thirty-four materials including worksheets, reading materials and teacher's guide could help to raise the awareness of LOHAS. Also these classes enabled the students to raise their awareness of LOHAS, to improve their opinions and attitudes on LOHAS consumption in the choice of clothing, and to take an interest in the lesson of Home-Economics. This study might have the educational significance in that it made the students directly participate in the national and social trend of the awareness of LOHAS, and upgrade their quality as good LOHAS consumers. Also further teaching-learning process plan in Home-Economics are necessary to promote the awareness of LOHAS for better health, environment, and society.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.3
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• pp.22-31
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• 2012

This study was prompted by the recognition that the tenn "Community design" has recently been used in diverse practical fields without prior discussion about its underpinnings, a potentially problematic state of affairs. Based on these problems, this study studied the special quality about the concept of community design. Community design can be discussed from two perspectives. The first views community design as a design that concerns the community, an inhabited area populated with people who have common interests, at least in part because of geographic proximity to each other. The second sees community design as a movement that started in the 1960s and places a great importance on democratic decision making, communication, and collaboration. This study will focus on the latter. This branch of community design encompasses an advocacy planning approach, in which design professionals represent deprived communities in their resistance against comprehensive redevelopment. This was associated to the wider social protest movements of the mid and late 1960s. In the 1970s, this branch of community design was developed alongside community design centers, which provided local-level technical assistance to the communities on a number of issues, such as design and planning. The discussion about community design started in earnest from the early 1980s. A review of the literature m community design reveals several characteristics. First, community design deals with the relationship between the physical environment and several aspects of a region, including the social and cultural. Second, it involves community participation, which many scholars believe is the core of community design. Specifically, community design has been characterized by increased participation and democratic debate and decision making. The Third is about communication methods. Since the 1960s, diverse methods had been developed to promote communication effectively. Finally, community design must consider the relationship between designers, who typically value aesthetics and efficiency of form, and the needs of the community with which they are working. Indeed, some scholars believe that this relationship is generally contentious, although the designer can also be thought of as the facilitator of the community's needs. As community design practice becomes more prevalent, a review of the foundation of institution and policy and the role of experts is also needed. The community design movement bas been theorized ex post facto through diverse discussion that has sought to ascribe meaning and direction to its practice. In other words, the relationship between this theory and practice is cyclical. Therefore, this study can contribute to the virtuous circle.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.3
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• pp.14-28
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• 2010

By philological geography method for dismantling and reconstituting Buyeo's Palkyung(扶餘 八景), which best signify the image of ancient city Buyeo's landscape, this research is to demonstrate the fact that the place's inertia of certain historic sites has been passed down as a type of geographic code. Titled poems and retrospective poems about Buyeo's Palkyung and its spectacles and landscapes reveal the fact that the splendid and glorious cultural heritage of Baekje had faded but its traces have remained in the each eight views including Nakhwa-am(落花巖), Goran-sa(皐蘭寺), and Jayong-dae(釣龍臺). In addtion, the spectacles and historic sites of Buyeo's Palkyung appear as the symbol of Baekje's fall and loss in the poems. Thus, it can be said that Buyeo's culture and civilization have never escaped from the cultural and historical scars of Baekhe's fall, being dominated by the place's inertia originated from the identity as "Baekje'slastcapital". It is ironical that Buyeo's future development and prosperity are not free from its cultural and historical spectacles which bear the image of the fall of Baekje. 'Older Buyeos' Palkyung(扶餘舊八景)' and, Prior Buyeo's Palkyung(夫餘前八景), originate from nine views of an unknown builder and after the construction of pavilions and towers, 'Subuk-jeong eight views(水北亭八景)' by Heungguk Kim(金興國) and the eight poems of the, Retrospect of Buyeo(扶餘懷古八景), were created. 'Buyeo's later Palkyung(扶餘後八景), which are especially free from the site's inertia are known to have expanded the scope of Buyeo's landscape by deliberately demonstrating spectacles and sites different from those of existing views. Nakhwa-am, Goran-sa, Joryong-dae, Songwal-dae(送月臺), Youngwal-dae(迎月臺), and Pyungje-tap(平濟塔) are all located within a one kilometer radius of Banwol-sung(半月城), Buyeo's palace and the Baekma river(白馬江), Daewang-po(大旺浦), Busan(浮山) in a two kilometers radius. Jaon-dae(自溫臺), Subuk-jeong(水北亭), and Gyuam-jin(窺岩津) are located within a three kilometers radius. Even Chunjeong-dae(天政臺), which are located within a four kilometers radius of Banwol-sung are located alongside the Baekma river. This indicates the fact that these spectacles had not been established temporarily or impromptu but for a long period time by historic retrospect and the inertia of landscape's geographic cycle. In conclusion, the geographic phenomenon of historical and cultural inertia appeared because Buyeo had the geographic message of "fallen, ancient city". Therefore, Buyeo's Palkyung which have constant retrospective inertia is clearly an geographic code effective and helpful to understand not only the characteristics of historic sites and spectacles of Buyeo in the Sabi period but also the quality of the site itself.

• Journal of Environmental Impact Assessment
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• v.28 no.6
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• pp.604-615
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• 2019

In this study, we produce a new type of the algae soil conditioner(ASC) using discarded algae biomass through a composting process and evaluate its nutritional characteristics. As the main ingredient, the ASCs used algae biomass collected through the coagulation-floating method and made by adding a variety of additional supporting materials (sawdust, pearlite, oilcake etc.). ASCs were divided into 0% in blank, 11.7% in ASC1, 21.6% in ASC2, 37.6% in ASC3, 59.5% in ASC4, and composted during 127 days. ASCs showed a sharp increase in temperature by aerobic microbial reaction, and 6~7 high and low temperature peaks were observed. As a result of physicochemical analysis, mineralization proceeded according to decomposing the organic matter and there was a marked increase not only in macronutrients (TN, P₂O₅, K₂O), but also in secondary macronutrients (CaO, MgO). The microbial community change was found in stage 1 (bacteria, filamentous fungi) → stage 2 (actinomycetes, bacteria) → stage 3 (Bacillus sp.), depending on the maturation process. It was estimated that microbial transition was closely related to temperature change and nutritional behavior. The quality of soil conditioner can be determined according to the maturity of compost process, and it was determined that effective microbial activity could be induced by controlling algae biomass below 59.5% in this study. In conclusion, we found out the possibility of manufacturing and utilizing soil conditioner recycled algae biomass and if further technological development is made on the basis it can be used as an effective soil conditioner.