• Title/Summary/Keyword: Contact potential

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Replacement of Saline Water through Injecting Fresh Water into a Confined Saline Aquifer at the Nakdong River Delta Area (염수로 충진된 낙동강 델타지역 피압대수층에서 담수주입에 의한 염수치환 연구)

  • Won, Kyung-Sik;Chung, Sang Yong;Lee, Chang-Sup;Jeong, Jae-Hoon
    • The Journal of Engineering Geology
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    • v.25 no.2
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    • pp.215-225
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    • 2015
  • We performed injection tests in a deep-seated confined aquifer to assess the potential of artificial recharge as a means of preventing saltwater contamination, thereby securing groundwater resources for the Nakdong Delta area of Busan City, Korea. The study area comprises a confined aquifer, in which a 10-21-m-thick clay layer overlies 31.5-36.5 m of sand and a 2.8-11-m-thick layer of gravel. EC logging of five monitoring wells yielded a value of 7-44 mS/cm, with the transition between saline and fresh water occurring at a depth of 15-38 m. Above 5 m depth, water temperature is 10-15.5℃, whereas between 5 and 50 m depth the temperature is 15.5-17℃. Approximately 950 m3 of fresh water was injected into the OW-5 injection well at a rate of 370 m3/day for 62 hours, after which the fresh water zone was detected by a CTD Diver installed at a depth of 40 m. The persistence of the fresh water zone was determined via EC and temperature logging at 24 hours after injection, and again 21 days after injection. We observed a second fresh water zone in the OW-2 well, where the first injection test was performed more than 20 days before the second injection test. The contact between fresh and saline water in the injection well is represented by a sharp boundary rather than a transitional boundary. We conclude that the injected fresh water occupied a specific space and served to maintain the original water quality throughout the observation period. Moreover, we suggest that artificial recharge via long-term injection could help secure a new alternative water resource in this saline coastal aquifer.

A Study on Characterization of Formation and Reduction of THMs in Water Treatment Process (정수처리공정별 THMs 발생특성과 저감방안에 대한 연구)

  • Ka, Gil-Hyun;Bae, Min-Ho;Lee, Jun-Ho;Ahn, Chi-Hwa;Han, Ihn-Sup;Min, Byung-Dae
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.7
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    • pp.721-728
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    • 2008
  • DBPs(Disinfection By-Products) are most formed through the reactions between chlorine and NOM(Natural Organic Matter) in water treatment. In this study, occurrence of DBPs including THMs(Trihalomethanes) is evaluated. Also, influencing factors by the seasons and raw water quality were investigated for correlation among them and the characteristics of THMs formation by prechlorination process. This study investigated the operation condition for THMs removal depending on raw water quality. Water treatment plant from intake station to gauging well flows for about 10 hours in Y Water Supply Office. It is limited to control of THMs formation because of excessive reaction time between chlorine and THMs precursors in the intake station. Therefore, as multi-points prechlorination from intake station to gauging well, THMs formation was decreased in the water treatment, and it was willing to prevent overdosage of chlorine. The concentration of THMs was 0.021 mg/L in the summer, 0.015 mg/L in the winter, respectively. Also, THMs formation showed that 0.013 mg/L in the water of gauging well after prechlorination, 0.014 mg/L in the flocculation/sedimentation/filtration, 0.016 mg/L in the water after postchlorination, respectively. THMFP(Trihalomethane Formation Potential) removed 42.7% and 50% through the flocculation/sedimentation and filtration, respectively, and it is similar TOC removal efficiency. In this study, multi-points prechlorination from intake station to gauging well decreases in contact time and concencrations of NOM and chlorine. Also, it decreases in THMs and amount of chlorine uesd. In the result of multi-points prechlorination in the summer, the concentration of THMs was 0.013mg/L in the treated water. In view of these facts, THMs formation can be decreased approximately 50%.

The Effects of Calcium-Phosphate Coated Xenogenic Bone and Type I Collagen for Bone Regeneration on the Calvarial Defects in Rabbits (Ca-P 박막 이종골과 제 1형 교원질이 토끼 두개골 결손부의 골재생에 미치는 영향)

  • Kim, Chang-Han;Park, Jin-Woo;Lee, Jae-Mok;Suh, Jo-Young
    • Journal of Periodontal and Implant Science
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    • v.34 no.1
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    • pp.223-241
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    • 2004
  • The purpose of this present study evaluated the osseous response around Ca-P coated xenogenic bone and compared osteogenic potential of Ca-P coated xenogenic bone to that of combination with type I collagen derived from bovine tendon as a biocompatible binder to prevent migration of bone particle on the repair of calvarial defects in rabbits. To study the effects of Ca-P coated xenogenic bone and collagen on bone healing, four 5-mm-diameter skull defect were made in calvaria with trephine filled with an autogenous bone chip or Ca-P coated xenogenic bone or Ca-P coated xenogenic bone and type I collagen (1:1 mixture by volume) or left empty. The defects were evaluated histologically at 1, 2, 4 and 8 weeks following implantation. Ca-P coated xenogenic bone at the calvarial defects of rabbits showed osteoconductivity at the margin of defect in the early stage of bony healing, but no direct contact with new bone was observed. With time passed by, it was resorbed slowly and showed consistent inflammatory reaction. An additional use of type I collagen derived from bovine tendon improved clinical handling, but no new bone formation was observed histologically. Above all, autogenous bone graft showed most prominent healing in quantity and density of new bone formation. According to this study, the use of Ca-P coated xenogenic bone alone and combination with type I collagen did not showed effective healing in quantity and density of new bone formation.

Management of plant genetic resources at RDA in line with Nagoya Protocol

  • Yoon, Moon-Sup;Na, Young-Wang;Ko, Ho-Cheol;Lee, Sun-Young;Ma, Kyung-Ho;Baek, Hyung-Jin;Lee, Su-Kyeung;Lee, Sok-Young
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.51-52
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    • 2017
  • "Plant genetic resources for food and agriculture" means any genetic material of plant origin of actual or potential value for food and agriculture. "Genetic material" means any material of plant origin, including reproductive and vegetative propagating material, containing functional units of heredity. (Internal Treaty on Plant Genetic Resources for Food and Agriculture, ITPGRFA). The "Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits Arising from their Utilization (ABS) to the Convention on Biological Diversity (shortly Nagoya Protocol)" is a supplementary agreement to the Convention on Biological Diversity. It provides a transparent legal framework for the effective implementation of one of the three objectives of the CBD: the fair and equitable sharing of benefits arising out of the utilization of genetic resources. The Nagoya Protocol on ABS was adopted on 29 October 2010 in Nagoya, Japan and entered into force on 12 October 2014, 90 days after the deposit of the fiftieth instrument of ratification. Its objective is the fair and equitable sharing of benefits arising from the utilization of genetic resources, thereby contributing to the conservation and sustainable use of biodiversity. The Nagoya Protocol will create greater legal certainty and transparency for both providers and users of genetic resources by; (a) Establishing more predictable conditions for access to genetic resources and (b) Helping to ensure benefit-sharing when genetic resources leave the country providing the genetic resources. By helping to ensure benefit-sharing, the Nagoya Protocol creates incentives to conserve and sustainably use genetic resources, and therefore enhances the contribution of biodiversity to development and human well-being. The Nagoya Protocol's success will require effective implementation at the domestic level. A range of tools and mechanisms provided by the Nagoya Protocol will assist contracting Parties including; (a) Establishing national focal points (NFPs) and competent national authorities (CNAs) to serve as contact points for information, grant access or cooperate on issues of compliance, (b) An Access and Benefit-sharing Clearing-House to share information, such as domestic regulatory ABS requirements or information on NFPs and CNAs, (c) Capacity-building to support key aspects of implementation. Based on a country's self-assessment of national needs and priorities, this can include capacity to develop domestic ABS legislation to implement the Nagoya Protocol, to negotiate MAT and to develop in-country research capability and institutions, (d) Awareness-raising, (e) Technology Transfer, (f) Targeted financial support for capacity-building and development initiatives through the Nagoya Protocol's financial mechanism, the Global Environment Facility (GEF) (Nagoya Protocol). The Rural Development Administration (RDA) leading to conduct management agricultural genetic resources following the 'ACT ON THE PRESERVATION, MANAGEMENT AND USE OF AGRO-FISHERY BIO-RESOURCES' established on 2007. According to $2^{nd}$ clause of Article 14 (Designation, Operation, etc. of Agencies Responsible for Agro-Fishery Bioresources) of the act, the duties endowed are, (a) Matters concerning securing, preservation, management, and use of agro-fishery bioresources; (b) Establishment of an integrated information system for agro-fishery bioresources; (c) Matters concerning medium and long-term preservation of, and research on, agro-fishery bioresources; (d) Matters concerning international cooperation for agro-fishery bioresources and other relevant matters. As the result the RDA manage about 246,000 accessions of plant genetic resources under the national management system at the end of 2016.

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Risk Assessment of Arsenic by Human Exposure of Contaminated Soil, Groundwater and Rice Grain (오염된 토양, 지하수 및 쌀의 인체노출에 따른 비소의 위해성 평가)

  • Lee Jin-Soo;Chon Hyo-Taek
    • Economic and Environmental Geology
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    • v.38 no.5 s.174
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    • pp.535-545
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    • 2005
  • Environmental survey from some abandoned metal mine areas was undertaken on to assess the risk of adverse health effects on human exposure to arsenic influenced by past Au-Ag mining activities. Elevated levels of As were found in tailings from the studied mine areas. This high concentration may have a impact on soils and waters around the tailing piles. In order to perform the human risk assessment, chemical analysis data of soils, rice grains and waters fur As have been used. The HQ values fer As via the rice grain and groundwater consumption were significantly higher compared with other exposure pathways in all metal mine areas. However, there were minimal soil and water dermal contact risks. The resulting Hl values of As from the Dongil, Okdong and Hwacheon mine areas were higher than 5.0, and their toxic risk due to drinking water and rice grain was strong in these mine areas. The cancer risk of being exposed to As by the rice grain route from the Dongil, Okdong and Hwacheon mine areas was $5.2\times10^{-4},\;6.0\times10^{-4}\;and\;8.1\times10^{-4}$, respectively. The As cancer risk via the exposure pathway of drinking water from these mine areas exceeded the acceptable risk of 1 in 10,000 fer regulatory purposes. Thus, the daily intakes of groundwater and rice grain by the local residents from the Dongil, Okdong and Hwacheon mine areas can pose a potential health threat if exposed by long-term arsenic exposure.

Hidden Porphyry-Related Ore Potential of the Geumseong Mo Deposit and Its Genetic Environment (금성 몰리브데늄광상의 잠두 반암형 광체에 대한 부존가능성과 성인적 환경)

  • Choi, Seon-Gyu;Park, Jung-Woo;Seo, Ji-Eun;Kim, Chang-Seong;Shin, Jong-Ki;Kim, Nam-Hyuck;Yoo, In-Kol;Lee, Ji-Yun;Ahn, Yong-Hwan
    • Economic and Environmental Geology
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    • v.40 no.1 s.182
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    • pp.1-14
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    • 2007
  • The Guemseong mine is located near the southern margin of the Jurassic Jecheon granitoids collectively with the Cambro-Ordovician mixed dolostone-limestone series of the Yeongweol Group, Choseon Supergroup. Here, two spatially distinct types of skarn formation have been observed. The upper transitional skarn is the calcic Mo skarn which has the mineral assemblage of $garnet+hedenbergite+epidote{\pm}wollastonite{\pm}magnetite{\pm}hematite{\pm}amphibole{\pm}chlorite{\pm}vesuvianite$ within the calcite marble. On the other hand, the lower proximal skarn occurs as a discordant magnesian Fe skarn at the contact of Mo-bearing aplitic cupolas with unidirectional solidification texture(UST) within the dolomitic marble. The magnesian Fe skarn has the mineral assemlage $olivine+diopside+magnetite+tremolite+serpentine+talc+chlorite{\pm}phlogopite$. The formation of two different types of skarn and ore mineralization in Geumseong mine have been attributed to multistage and complex metasomatic replacements that ultimately resulted in silicate-oxide-sulfide sequence of metasomatism. An early prograde stage with anhydrous skarn minerals such as olivine, clinopyroxene and/or garnet with magnetite, formed from high temperature (about $500^{\circ}\;to\;400^{\circ}C$) at an environmental condition of low $CO_2$ fugacity ($XCO_2<0.1$) and 0.5 kbar. The later retrograde stage with hydrous silicates such as amphibole, serpentine, phlogopite, epidote and chlorite with molybdenite or hematite, termed from relatively lower temperature (about $400^{\circ}\;to\;300^{\circ}C$).

A Survey on the Workplace Environment and Personal Protective Equipment of Poultry Farmers (양계 농업인의 작업장 환경 및 개인보호구 착용 실태조사)

  • Kim, Insoo;Kim, Kyung-Ran;Lee, Kyung-Suk;Chae, Hye-Seon;Kim, Sungwoo
    • Journal of Environmental Health Sciences
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    • v.40 no.6
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    • pp.454-468
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    • 2014
  • Objectives: This study was conducted to investigate the actual condition of the farm work environment and personal protective equipment as part of the effort to improve livestock work for the safety and health of poultry farmers and provide basic data for establishing plans to improve and develop personal protective equipment. Methods: For this purpose, a questionnaire survey on general information about stables, the poultry work environment, accidents, the wearing of work clothes and personal protective equipment, and the level of awareness related to personal protective equipment was conducted among 148 poultry farmers. Results: As a result, it was found that poultry workplace environment was exposed to such risks as fine dusts; organic dusts; poisonous gases; odorous substances; chicken excrement; contact with chickens, bacteria or viruses; and accidents related to machine operation. Thirteen percent of respondents suffered severe respiratory diseases, and the most frequently injured sites due to accidents were the hands (25.7%), knees (23.8%), arms (17.3%), and head (10.9%). The most frequent type of accident was collisions between the body and obstacles or machinery during movement (36.4%), followed by erroneous machine operation such as feeders and electric shocks (8.5%). Regarding the wearing of work clothes and personal protective equipment, 51.7% of the respondents wore worn-out clothing or everyday clothes, whereas only 32.0% wore work clothes. The percentage of farmers who wore proper protective equipment for the work environment during poultry work was 48.4%. The most frequently used type of protective equipment was boots (38.9%), followed by mask (36.7%), gloves (36.3%), appropriate work clothes (22.6%), quarantine clothes (17.6%), helmets (13.4%), and goggles (12.6%). The rate of wearing goggles was low because they were considered inconvenient and lowered work efficiency. Furthermore, they purchased everyday products available on the market for their personal protective equipment which were not appropriate for maintaining safety in an actual harmful environment and its consequent risks. As a result of the survey of the awareness level related to personal protective equipment, their levels of awareness of accidents and attitude proved to be average or higher, but the practice of wearing protective equipment and the level of knowledge and management of personal protective equipment were lower. Conclusion: This survey found that the wearing status of personal protective equipment among poultry farmers was insufficient even though they were exposed to risks. Most respondents were aware of the necessity of wearing personal protective equipment and of the potential for accidents, but they did not wear proper protective equipment. Their wearing rate was low due to a lack of knowledge about protective equipment, as well as the inconvenience of wearing it. Therefore there is a need to improve and develop specialized personal protective equipment for respiration, hands, and eyes, as well as work clothes that can protect farmers from major harmful matter that is generated in the poultry workplace. Based on the results of this investigation, we will conduct further studies on the required performance and design directions of personal protective equipment while collecting more objective data through field-oriented assessments.

The experimental study of early loading on the Miniplate in the beagle dog (성견의 하악골에 식립된 Miniplate에 가한 조기 부하의 영향에 관한 실험적 연구)

  • Chung, Yong-Koo;Lee, Young-Jun;Chung, Kyu-Rhim
    • The korean journal of orthodontics
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    • v.33 no.4 s.99
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    • pp.307-317
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    • 2003
  • Conventional osseointegrated titanium implants have many limitations; large size, limited location for placement of the implant, severity of the surgery, discomfort of initial healing, difficulty of oral hygiene and uncontrollable force direction. Recently titanium miniscrew and miniplate have been used for an alternative to conventional dental implant. But in relation to miniplate, miniscrew has disadvantages in that more potential inflammation, light orthodontic force application and limited orthodontic application. This study was conducted to evaluate the effectiveness of miniplate by observing the reactions of peri-implant tissues to early orthodontic and orthopedic loading of titanium miniplate. In four adult beagle dogs 10 miniplates were inserted into the alveolar bone using 20 osseointegrated titanium screws. 4 miniplates were placed in two dogs(dogA, B) and 6 miniplates in two dogs(dogC, D). In dogA, B miniplates were loaded with 200gm of force immediately after placement for 15 weeks. In dogc, D, miniplates were loaded with 400gm of force immediately after placement for 8 weeks. Miniplates of dogA were removed, dogA was healed for 4 weeks, and the area which was removed of miniscrew was examined. Following an observation period, the miniplates including miniscrews and the surrounding bone of dogB and dogC, D were removed, respectively. Undecalcified section along the long axis of miniscrews were made and the degree of osseointegration was examined under the light microscope. The results were as follows. 1. In the histologic features there was direct contact between bone and miniscrew in all groups except one, dogC control group. The loaded miniscrew demonstrated only a slight increase of the osseous proximaty when compared with unloaded miniscrew 2. There was no significant difference of the osseointegration of Peri-miniscrew surface between dogB and dogC, D. But dogB showed slightly more increased bone apposition than dogC, D 3. The gingiva overlapping the miniplate and miniscrew showed no inflammatory sign in clinical and histological aspects. 4. The impaled hard and soft tissues at the area which was removed of miniscrews showed good healing without inflammatory reaction. 5. The mobility showed slight increase in un-loaded miniplate but that was insignificant. Based on the results of this study, miniplate(C-tube) can be used as a firm osseous orthodontic and orthopedic anchorage unit immediately after insertion.

Retrospective study on survival, success rate and complication of implant-supported fixed prosthesis according to the materials in the posterior area (구치부 임플란트 지지 고정성 보철물의 재료에 따른 생존율, 성공률 및 합병증에 대한 후향적 연구)

  • Chae, Hyun-Seok;Wang, Yuan-Kun;Lee, Jung-Jin;Song, Kwang-Yeob;Seo, Jae-Min
    • The Journal of Korean Academy of Prosthodontics
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    • v.57 no.4
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    • pp.342-349
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    • 2019
  • Purpose: The purpose of this study was to retrospectively investigate the survival and success rate of implant-supported fixed prosthesis according to the materials in the posterior area. Other purposes were to observe the complications and evaluate the factors affecting failure. Materials and methods: Patients who had been restored implant prosthesis in the posterior area by the same prosthodontist in the department of prosthodontics, dental hospital, Chonbuk National University, in the period from January 2011 to June 2018 were selected for the study. The patient's sex, age, material, location, type of prosthesis and complications were examined using medical records. The KaplanMeier method was used to analyze the survival and success rate. The Log-rank test was conducted to compare the differences between the groups. Cox proportional hazards model was used to assess the association between potential risk factors and success rate. Results: A total of 364 implants were observed in 245 patients, with an average follow-up of 17.1 months. A total of 5 implant prostheses failed and were removed, and the 3 and 5 year cumulative survival rate of all implant prostheses were 97.5 and 91.0, respectively. The 3 and 5 year cumulative success rate of all implant prostheses were 61.1% and 32.9%, respectively. Material, sex, age, location and type of prosthesis did not affect success rate (P>.05). Complications occurred in the order of proximal contact loss (53 cases), retention loss (17 cases), peri-implant mucositis (12 cases), infraocclusion (4 cases) and so on. Conclusion: Considering a high cumulative survival rate of implant-supported fixed prostheses, regardless of the materials, implant restored in posterior area can be considered as a reliable treatment to tooth replacement. However, regular inspections and, if necessary, repairs and adjustments are very important because of the frequent occurrence of complications.

The Effect of Marketing Mix elements on brand Equity (마케팅 믹스 요소가 브랜드 자산에 미치는 영향에 관한 연구)

  • Ryu, Jang-Mu
    • Journal of Industrial Convergence
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    • v.1 no.1
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    • pp.41-70
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    • 2003
  • Many researches on brand equity have been focused in definition about it, factors of it, and the process of formation. Most of them have been used by voluntary production category, as is durable goods or nondurable goods. But this study, using the model is developed by Foote, Cone & Be1ding(FCB) Company, classified four fields, high-low involvement, rationality(rational or sensitive) involvement. The selected goods is a sensitive high involvement(casual wear). This study investigate the effects of brand equity and search the influences of brand equity formation according to factors of marketing mix. To this goals, this study kept a literature survey and a demonstrative research. In literature survey, there are several definitions of brand and brand equity. The research model is derived from selected factors of marketing mix and former study. This study used the regression analysis to verify effects from brand equity through the selected marketing mix. The research data is collected from the capital area. The focus of this study is effects of brand equity according to marketing mix. The followings are results and suggestions of this study. First, in the price factors, the affirmative effects are revealed the perceived quality and the brand awareness in a rational high involvement goods, the perceived quality and the brand associations in a sensitive high involvement goods, all factors of brand equity in a rational low involvement goods, and the perceived quality in a sensitive low involvement goods. As summary, the important characteristics is the price factors to consumers, and consumers recognize that a high price means a high quality. Second, in the store image factors, the affirmative effects are revealed all brand equity factors in a rational high involvement and a sensitive high-low involvement. A good store image incites more interest, contact, and visit from potential consumer. And such store offers more consumer satisfaction, simulates more active and positive conversation to consumers. Third, in advertising spending factors, the affirmative effects are revealed the brand awareness and associations in a rational high involvement and a sensitive high involvement, all brand equity factors in a rational low involvement and a sensitive low involvement. An advertisement increases not only a brand awareness but also strong brand associations. Forth, in price promotion factors, the affirmative effects are revealed the brand associations in a rational high involvement, the negative effects are revealed all brand equity in sensitive high involvement. According the result about the effects of brand royalty through the brand equity factors, a perceived quality and brand associations have positive effects to brand royalty in all factors. Consumers choice a deep perceived quality than other competitive brand. So, brand equity will increase according to a qualitative grade of a perceived brand by consumers. Brand associations represent a quality and a degree of involvement. In conclusion, brand associations and equity have a positive relation each other. According to the analysis results about a brand royalty of selected marketing mix factors, the affirmative effects are revealed the store image and price promotion factors in a rational high involvement, the price and store image in a sensitive high involvement, and the price and advertising spending in a rational low involvement. The results about the affect of selected marketing mix factors according to brand equity, are the perceived quality in a high involvement, and all brand equity factors in a low involvement. The affirmative effects about a store image are revealed all equity factors in high-low involvement. In advertising spending factors, the affirmative effects are revealed the brand awareness and associations in a high involvement goods, and the perceived quality and the brand awareness in a low involvement goods. In price promotion factors, the affirmative effects are revealed the brand awareness in a low involvement goods, and the negative effects are revealed the brand awareness in a high involvement goods. According to a degree of involvement, the results of a brand royalty through a brand equity factors are following. The affirmative effects are revealed the perceived quality and the brand royalty in a high involvement goods, and the brand awareness are revealed a negative effect. The affirmative effects are revealed the perceived Quality and the brand associations in a low involvement goods. So, in a high involvement goods, the brand royalty is built by strong brand associations, but, in a low involvement goods, the brand royalty is built also by a perceived Quality and a brand awareness. This study have some concept of limitation. So, this study presents a future direction of research. First, a future study has to have more deep analysis for this study analyzed through a limited marketing mix factors. Second, a future research has to get mutual effects about brand equity of marketing mix factors for this study has an individual marketing decision factors. Third, for the future, a brand equity needs a research about a several goods such as services, profit or nonprofit, industrial products, culture, and so on. Forth, the research have to diversify a various data for population.

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