• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.1
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• pp.32-44
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• 2023

Purpose: The purpose of this study was to investigate the effect of implant connection type on marginal bone loss (MBL) and to analyze the factors that affect MBL. This study focuses on single implants planted in the upper and lower first molar area. Materials and Methods: A total of 87 implants from 68 patients were tracked for a period over 5 years. There were 57 external connection type (EC) implants and 30 internal connection type (IC) implants in 38 males and 30 females. The MBL and EA were measured from intraoral radiograph images taken after 5 years at most. Results: Significant difference in MBL between EC and IC type was observed in patients without GBR or diabetes. Patients without GBR exhibited an MBL of -0.065 ± 0.859 mm in EC type and -0.627 ± 0.639 mm in IC type (P = 0.025). Using multiple regression analysis, a statistically significant negative correlation was observed between MBL and conditions including implant-abutment connection type (β = -0.303), diabetes (β = -0.113), emergence angle > 30° (β = -0.234), and age (β = -0.776). Conclusion: Within this results, IC type implants had less MBL than EC type, and implant prosthesis with emergence angle over 30° showed greater MBL. To minimize the MBL of the implant and ensure implant stability, careful consideration should be given to the EA of implant prosthesis and its connection type.

• Journal of dental hygiene science
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• v.10 no.1
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• pp.17-24
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• 2010

The purpose of this study was to provide the basic data for effective intervention of oral health behaviors strategy and to compare the actual conditions about hypertension and diabetes case management of the elderly at the hall for the aged and the D senior's college. The research method was a questionnaire including hypertension and diabetes case management of the elderly and the subjects were 174 of the elderly(65 age over) at the hall for the aged(100) and the senior's college(74). The results of this study were as follows; 1. Hypertension 1)The incidence of hypertension of elderly at the hall for the aged and the senior's college were 32.2%. 2)83.9% of the hypertension cases were initially diagnosed during hospital examination(p < 0.05). 3)Regular blood pressure checks were performed more than one time monthly on 76.8% of the cases(p < 0.05). 4)Blood pressure control was well controlled on 75%(p < 0.05). 5)85.7% of the elderly at the hall for the aged took hypertension drugs daily and 42.9% of the elderly at the senior's college took no drug alternatively(p < 0.05). 2. Diabetes 1)The incidence of the diabetes of elderly at the hall for the aged and the senior's college were 14.4%. 2)80.0% of the diabetes cases were initially diagnosed during hospital examination(p < 0.05). 3)64.0% of the cases did not have blood sugar measuring instrument(p < 0.05). 4. In the quality of life, the thinking of no difficulty in walking and no anxiety/depression was more presented on the elderly at the senior's college than those at the hall for the aged(p < 0.05). 5. The subjective health condition scores were higher on the elderly at the senior's college than those at the hall for the aged(p < 0.05).

• Restorative Dentistry and Endodontics
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• v.25 no.3
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• pp.390-398
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• 2000

The purpose of this study was to evaluate the apical fitness of non-standardized gutta-percha cones in root canals prepared with rotary Ni-Ti root canal instruments of various tapers and apical tip sizes. Simulated sixty curved root canals of plastic blocks were prepared with crown-down technique using rotary root canal instruments of Maillefer ProFile$^{(R)}$ .04 and .06 taper (Maillefer Instrument SA, Switzerland). Specimens were divided into six groups and prepared as follows: Group 1, prepared up to size 25 of .04 taper ; Group 2, prepared up to size 30 of .04 taper ; Group 3, prepared up to size 35 of .04 taper ; Group 4, prepared up to size 25 of .06 taper ; Group 5, prepared up to size 30 of .06 taper ; Group 6 ; prepared up to size 35 of .06 taper. After cutting off the coronal portion of plastic, blocks perpendicular to the long axis of the canal with the use of a diamond saw, apical 5mm of canal space was analyzed. Prepared apical canal spaces were duplicated using rubber base impression material to evaluate two dimensional total area of apical canal space. Various sized gutta-percha cones were applied in the 5mm-apical canal space, which were size 25, size 30 and size 35 standardized gutta-percha cone, Diadent Dia-Pro ISO-.04$^{TM}$ and .06$^{TM}$(Diadent, Korea), and medium-fine (MF), fine (F), fine-medium (FM) and medium (M) sized non-standardized gutta-percha cones (Diadent, Korea). Coronal excess gutta-percha were cut off with a sharp blade. Photographs of impressed apical canal spaces and gutta-percha cones were taken with a CCD camera under a stereomicroscope and stored in a computer. Areas of the total canal space and gutta-percha cones were calculated using a digitalized image analysing program, CompuScope (Sungjin Multimedia Co., Korea). Ratio of apical fitness was obtained by calculating the area of gutta-percha cone to the total area of the canal space. The data were analysed statistically using One-way Analysis of Variance and Duncan's Multiple Range Test. The results were as follows: 1. In canals prepared up to size 25 ProFile$^{(R)}$ of .04 taper, non-standardized MF and F cones occupied significantly more canal space than Dia-Pro ISO-.04$^{TM}$ or size 25 standardized ones (p<0.05). 2. In canals prepared up to size 30 ProFile$^{(R)}$ of .04 taper, non-standardized F cones occupied significantly more canal space than Dia-Pro ISO-.04$^{TM}$ or size 30 standardized ones (p<0.05), and non-standardized MF cones occupied more canal space than size 30 standardized ones (p<0.05). 3. In canals prepared up to size 35 ProFile$^{(R)}$ of .04 taper, there was no significant difference in canal space occupation among non-standardized MF and F, size 35 standardized, and Dia-Pro ISO-.04$^{TM}$ cones (p>0.05). 4. In canals prepared up to size 25 ProFile$^{(R)}$ of .06 taper, non-standardized MF and F cones occupied significantly more canal space than Dia-Pro ISO-.06$^{TM}$, or size 25 standardized ones (p<0.05), and Dia-Pro ISO-.06$^{TM}$, cones occupied significantly more space than size 25 standardized ones (p<0.05). 5. In canals prepared up to size 30 ProFile$^{(R)}$ of .06 taper, non-standardized FM cones occupied significantly more canal space than Dia-Pro ISO-.06$^{TM}$ or size 30 standardized ones (p<0.05), and non-standardized F cones occupied significantly more canal space than size 30 standardized ones (p<0.05). 6. In canals prepared up to size 35 ProFile$^{(R)}$ of .06 taper, non-standardized M and FM, Dia-Pro ISO-.06$^{TM}$ occupied significantly more canal space than size 35 standardized ones (p<0.05). In summary, in both canals prepared with .04 or .06 taper ProFile$^{(R)}$, non-standardized cones showed better fitness than Dia-Pro ISO$^{TM}$ or standardized ones, which was more characteristic in smaller canals.

• Journal of Oral Medicine and Pain
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• v.32 no.2
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• pp.187-200
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• 2007

This study attempted to contribute to the clinical application of implant operation by making a quantitative nerve examination using a neurometer for the evaluation of sensory disturbances that could be incurred after the implantation in the dental clinics, and it intended to establish an objective guideline in the evaluation of sensory nerve after the operation of implant. An inspection was performed with the frequencies of 2000Hz, 250 Hz and 5 Hz before and after the operations of tooth implant using $Neurometer^{(R)}$ CPT/C (Neurotron, Inc. Baltimore, Maryland, USA) for 44 patients who had performed an implant operation among the patients coming to Daejeon Sun Dental Hospital in 2006 and 30 people for control group. The measuring sites were maxillary nerve ending and mandibular nerve ending of trigeminal nerve according to the implant operating regions. The current perception threshold (CPT) by each nerve fiber was specifically responded under the electric stimulation of 2000 Hz in case of $A{\beta}$ fiber and of 250 Hz in case of $A{\delta}$ fiber and of 5Hz in case of C fiber. The CPT test could be performed to assess the damages of peripheral nerve in the trigeminal nerve area and it stimulated selective nerve fibers by generating the electricity of specific frequency in the peripheral nerve area. The nerve fibers with varied thickness were responsive selectively to the electric stimulation with different frequencies; accordingly, they applied the electric stimulation with different frequencies and the reaction threshold of $A{\beta},\;A{\delta}$ and C fibers selectively responsive to each electric current could be individually evaluated. In the assessment through the CPT, the increase and decrease of the CPT could be measured so that sensory disturbances such as hyperaesthesia or hypoaesthesia could be diagnosed. This study could obtain the following results after the assessment of the CPT before and after the implant operation. 1. In the assessment before and after the implant operation, the CPT in the frequencies of 2000 Hz, 250 Hz, 5 Hz for maxillary branch increased on the whole after the operation and the CPT for mandibular branch in the $A{\beta}$-fiber(2000 Hz) and C-fiber(5 Hz )after the operation increased statistically significantly. 2. For the groups of patients with medically compromised or its subsequent medicinal prescription, there were no significant differences before and after the implant operation and for the control groups, significantly high CPT was shown after the implant operation in the left $A{\beta}$-fiber(2000 Hz) and C-fiber(5 Hz). 3. In the comparison of the measured value of the CPT before the operation between the control group and the implant operation group, the latter group had a significantly high measured value of the CPT in the right $A{\beta}$-fiber(2000 Hz) and C-fiber(5 Hz) and there were significant differences in $A{\beta}$-fiber(2000 Hz) in the CPT assessment after the implant operation for the control group. 4. Male participants had higher CPT than female counterparts; however, there were no statistic significances. In the CPT evaluation before and after implant operation, there were no statistical differences in the male group while the right C-fiber(5 Hz) and left $A{\beta}$-fiber(2000Hz) were significantly high in the female group. 5. In the comparison between the group who complain sensory disturbance and the other group, the CPT increased on the whole in the former group, but there were no statistical significances. In the groups, whom there was an increase in VAS, the CPT after the implant operation in the right C-fiber(5 Hz) increased significantly; meanwhile, in case that the VAS mark was '0' before and after the operation, the CPT after the operation in the left $A{\beta}$-fiber(2000 Hz) increased significantly. This study suggested that the CPT measurements using $Neurometer^{(R)}$ CPT/C, provide useful information of objective and quantitative sensory disturbances for tooth implantation.

• Journal of Oral Medicine and Pain
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• v.32 no.4
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• pp.441-447
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• 2007

Internal derangement of the temporomandibular joint(TMJ) is defined as an abnormal relationship of the articular disc to the condyle. Mandibular manipulation is one of the conservative treatments to be considered first to manage the patients with anterior disc displacement without reduction. Mandibular manipulation is used to increase articular mobility and to restore the displaced disc into an anatomically normal position. While Farrar's technique has been popularly used, Minagi et al., Mongini and Suarez introduced the manipulation technique conducted by the patients themselves. But there is no study on the efficacy of self-manipulation technique, comparing with conventional one. The aim of this study was to investigate the efficacy of the conventional and self-manipulation technique, which was modified to complement the previously described technique by Minagi et al., in the treatment of patients with anterior disc displacement without reduction. TMD patients, who visited Department of Oral Medicine of Seoul National University Dental Hospital from December, 2002 to November, 2004 and were diagnosed as anterior disc displacement without reduction by TMJ magnetic resonance imaging (MRI) were enrolled. Conservative treatments including physical therapy, exercise, behavioral therapy, stabilization splint therapy, and manipulation therapy were done to every single patient until the symptomsimproved enough to discharge the patient. The charts were reviewed retrospectively according to the type of manipulation. In the results, patients whose maximum mouth opening was more than 40 mm was higher in the self-manipulation group(69.9%) than in the conventional manipulation group(42.9%). But difference between two groups was not significant. According to the fact that we decided to discharge the patients whentheir mouth opening increased to more than 40 mm and subjective symptoms such as pain and discomfort were improved as well, treatment period of discharged patients was significantly shorter in the self-manipulation group($29.2{\pm}12.3$ weeks) than in the conventional manipulation group ($61.0{\pm}38.0$ weeks) (p<0.01). In conclusion, in the treatment of TMD patients with anterior disc displacement without reduction, the self-manipulation technique which is performed by patients themselves is an effective treatment modality for increasing the range of mouth opening and shortening the total treatment period.

• Restorative Dentistry and Endodontics
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• v.32 no.2
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• pp.138-150
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• 2007

The purpose of this study was to evaluate the difference of surface roughness of composite resin according to composite resin type, polishing methods, and use of resin sealant. Two hundred rectangular specimens, sized $8{\times}3{\times}2mm$, were made of Micro-new (Bisco, Inc., Schaumburg, IL, U.S.A) and Filtek Supreme (3M ESPE Dental Products, St. Paul, MN, U.S.A.), and divided into two groups; Micronew-M group, Filtek Supreme-S group. Specimens for each composite group were subdivided into five groups by finishing and polishing instruments used; M1 & S1(polyester strip), M2 & S2 (Sof-Lex disc), M3 & S3 (Enhance disc and polishing paste), M4 & S4(Astropol) and M5 & S5 (finishing bur), Polished groups were added letter B after the application of resin surface sealant (Biscover), eg, M1B and S1B. After specimens were stored with distilled water for 24hr, average surface roughness (Ra) was taken using a surface roughness tester. Representative specimens of each group were examined by FE-SEM (S-4700: Hitachi High Technologies Co., Tokyo, Japan). The data were analysed using paired t-test, ANOVA and Duncan's tests at the 0.05 probability level. The results of this study were as follows ; 1. The lowest Ra was achieved in all groups using polyester strip and the highest Ra was achieved in M5, S5 and M5B groups using finishing bur. On FE-SEM, M1 and S1 groups provided the smoothest surfaces, M5 and S5 groups were presented the roughest surfaces and voids by debonding of filler on the polished specimens. 2. There was no significant difference in Ra between Micronew and Filtek Supreme before the application of resin sealant, but Micronew was smoother than Filek Supreme after the application of resin sealant. 3. There was significant corelation between Ra of type of composite resin and polishing methods before the application of resin sealant (p=0.000), but no significant interaction between them after the application of resin sealant. On FE-SEM, most of composite resin surfaces were smooth after the application of resin sealant on the polished specimens. 4. Compared with before and after the application of resin sealant in group treated in the same composite and polishing methods, Ra of M4B and M5B was statistically lower than that of M4 and M5, and S5B was lower than that of S5, respectively (p<0.05). In conclusion, surface roughness by polishing instruments was different according to type of composite resin. Overall, polyester strip produced the smoothest surface, but finishing bur produced the roughest surface. Application of resin sealant provided the smooth surfaces in specimens polished with Enhance, Astropol and finishing bur, but not provided them in specimens polished with Sof-Lex disc.

• Journal of dental hygiene science
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• v.4 no.3
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• pp.141-148
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• 2004

This study was examed in order to determine influential factors of health promoting behavior on Dental Hygiene students the health promoting behavior. So examed students' health promoting behavior, self-efficacy, perceived benefit, perceived barrier, a health locus of control, self-esteem. A the result of this study were as follows: (1) Performance mean score in health promoting behavior was 2.60, self achievement score was 2.89, health responsibility score was 2.12, exercise score was 1.89, nutrition score was 2.45, interpersonal support score was 2.97, stress management score was 2.63. Performance mean score in self-efficacy was 2.56, perceived benefit was 3.45, perceived barrier was 2.32, a health locus of control score was 3.04, self-esteem score was 2.81. (2) Performance in health promoting behavior was significant differences in year, religion, economical level, experience of disease on family, perceived health status(p<0.05), perceived oral health status(p<0.001). Performance in self achievement was significant differences in year, economical level, perceived health status(p<0.05), religion, perceived oral health status(p<0.01). Performance in health responsibility was significant differences in year, religion, economical level, BMI(p<0.05) and experience of disease on myself, perceived oral health status(p<0.001). Performance in excercise was significant differences in mother's educational level, experience of disease on family, perceived oral health status(p<0.05) and nutrient was economical level, perceived oral health status(p<0.01), perceived health status(p<0.05). Performance in interpersonal relations was only significant differences perceived oral health status(p<0.05) and in stress management was year, perceived oral health status(p<0.05). (3) Performance in self-efficacy was significant differences in economical level, health status(P<0.05) and perceived health status, perceived oral health status(p<0.01). Performance in perceived benefit was significant differences in religion(p<0.05). Performance in perceived barrier was significant differences economical level, perceived oral health status(p<0.05), experience of disease on myself(p<0.01). Performance in a health locus of control was significant differences year(p<0.05), performance in a perceived oral health status(p<0.01). (4) Performance in health promoting behavior was significantly correlated with self-efficacy(r=0.376), perceived benefit(r=0.188), perceived barrier(r=-0.155), a health locus of control (r=0.064), self-esteem(r=0.318). (5) Self-efficacy was the highest factor predicting health promoting behavior.

• Restorative Dentistry and Endodontics
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• v.32 no.3
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• pp.248-259
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• 2007

The aim of this research was to study the effect of intermittent polymerization on marginal adaptation by comparing the marginal adaptation of intermittently polymerized composite to that of continuously polymerized composite. The materials used for this study were Pyramid (Bisco Inc., Schaumburg, U.S.A.) and Heliomolar (Ivoclar Vivadent, Liechtenstein) . The experiment was carried out in class II MOD cavities prepared in 48 extracted human maxillary premolars. The samples were divided into 4 groups by light curing method: group 1- continuous curing (60s light on with no light off), group 2-intermittent curing (cycles of 3s with 2s light on & 1s light off for 90s); group 3- intermittent curing (cycles of 2s with 1s light on & 1s light off for 120s); group 4- intermittent curing (cycles of 3s with 1s light on & 2s light off for 180s). Consequently the total amount of light energy radiated was same in all the groups. Each specimen went through thermo-mechanical loading (TML) which consisted of mechanical loading (720,000 cycles, 5.0 kg) with a speed of 120 rpm for 100hours and thermocycling (6000 thermocycles of alternating water of $50^{\circ}C$ and $55^{\circ}C$). The continuous margin (CM) (%) of the total margin and regional margins, occlusal enamel (OE), vertical enamel (VE), and cervical enamel (CE) was measured before and after TML under a $\times200$ digital light microscope. Three-way ANOVA and Duncan's Multiple Range Test was performed at 95% level of confidence to test the effect of 3 variables on CM (%) of the total margin: light curing conditions, composite materials and effect of TML. In each group, One-way ANOVA and Duncan's Multiple Range Test was additionally performed to compare CM (%) of regions (OE, VE CE). The results indicated that all the three variables were statistically significant (p < 0.05). Before TML, in groups using Pyramid, groups 3 and 4 showed higher CM (%) than groups 1 and 2, and in groups using Heliomolar. groups 3 and 4 showed higher CM (%) than group 1 (p < 0.05). After TML, in both Pyramid and Heliomo)ar groups, group 3 showed higher CM (%) than group 1 (p < 0.05) CM (%) of the regions are significantly different in each group (p < 0.05). Before TML, no statistical difference was found between groups within the VE and CE region. In the OE region, group 4 of Pyramid showed higher CM (%) than group 2, and groups 2 and 4 of Heliomolar showed higher CM (%) than group 1 (p < 0.05). After TML, no statistical difference was found among groups within the VE and CE region. In the OE region, group 3 of Pyramid showed higher CM (%) than groups 1 and 2, and groups 2,3 and 4 of Heliomolar showed higher CM (%) than group 1 (p < 0.05). It was concluded that intermittent polymerization may be effective in reducing marginal gap formation.

• Asia Marketing Journal
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• v.14 no.2
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• pp.209-237
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• 2012

1. Research Purpose Consumers rely on various clues to evaluate their decision to patronize a retail store, and store brand is one of them (Dodds 1991; Grewal et al. 1998). As consumers find ever increasing variety of contact points connecting them to specific store, the value of experiential shopping as a means of increasing store's brand equity warrants greater attention from scholars of retail management. Retail shopping values are credited for creating not only cognitive experiences like brand knowledge but also emotional experiences such as shopping pleasure and pride (Schmitt 1999). This may be because today's consumers place emphasis on emotional values associated with shopping pleasure, lifestyle brought to life, brand relationship, and store atmosphere more than utilitarian values such as product quality and price. Many previous literature found this to be true (Ahn and Lee 2011; Mathwick et al. 2001). This brings forth important research issues and questions regarding the roles of shopping experiential values and brand equity with regard to consumer's retail patronage choice. However, despite this importance, research on this area remains quite inadequate (Hwang 2010). For this reason, this study aims to verify the relationships among experiential shopping values, retail store brand equity and tries to link that with customer loyalty by surveying large-scale discount store shoppers in Korea and China. 2. Research Contents In order to carry out the research objective, this study conducted comprehensive literature survey on previous literature by discussing major findings and implications with regard to shopping values and retail brand equity and store loyalty. For data collection, researcher employed survey-based research method where data were collected in two major cities of Korea (Seoul) and China (Bejing) and sampling frame was based on patrons of large discount stores in both countries. Specific research questions raised in this study are as follows; RQ1: How do Korean and Chinese consumers differently perceive of shopping values regarding shopping at large-sclae discount stores? RQ2: Are there differences in consumers' emotional consumption propensities? RQ3: Do Korean and Chinese consumers display different perceptions of brand equity towards large-scale discount stores? RQ4: Are there differences in relationships between shopping values and brand equity for Korean and Chinese consumers? For statistical analysis, SPSS17.0, AMOS17.0 and SmartPLS were employed. 3. Research Results The data collected through face-to-face survey conducted in Seoul and Bejing revealed appropriate data validity and reliability as a result of exploratory/confirmatory factor analysis and reliability tests, andh SEM model yielding satisfactory model fitness. The result of the study may be summarized by three main points. First, as a result of testing differences in consumption dispositions, Chinese consumers showed higher scores in aesthetic and symbolic dispositions, whereas Korean consumers scored higher in hedonic disposition. Second, testing on perceptions toward brand equity of large discount stores showed that Korean consumers exhibited more positive perceptions of brand awareness and brand image than Chinese counterparts. Third, the result of exploratory factor analysis on the experiential shopping values revealed different factors for each country. On Korean side, consumer interest value, aesthetic value, and hedonic value were prominent, whereas on Chinese side, hedonic value, aesthetic value, consumer interest value, and service excellence value were found salient. 4. Research Implications While many previous studies on inter-country differences in retailing area mainly focused on cultural dispositions or orientations to explain the differences, this study sets itself apart by specifically targeting individual consumer's shopping values from an experiential viewpoint. The study result provides important theoretical as well as practical implications for large-scale discount store, especially the impotance of fully exploring the linkage between shopping values and brand equity, which has significant influence on loyalty. Therefore, the specific implications deriving from the result shed some important insights upon the consumption values based on shopping experiences and brand equity. The differences found in store shoppers between the two countries may also provide useful insights for Korean and Chinese retailers who plan to expand their operations globally. Related strategic implications derived from this study is the importance of localizing retail strategy which is based on the differences found in experiential shopping values between the two country groups. Especially the finding that Chinese consumers value consumer interest and service excellence, whereas Koreans place importance on hedonic or aesthetic values indicates the need to differentiate the consumer's psychographical profiles when it comes to expanding retail operations globally. Particularly important will be to pursue price-orienated strategy in China in consideration of the high emphasis on consumer interests and service excellence, but to emphasize the symbolic aspects of brand equity in Korea by maximizing the brand equity associated with aesthetic values and hedonic orientations. 5. Recommendations This study focused on generic retail branded discount stores in both countries, thus making it difficult to tease out store-specific strategies based on specific retail brands. Future studies may benefit fro employing actual brand names in survey questionnaire to verify relationship between shopping values and brand-based store strategy. As with other studies of this nature, this study needs to strengthen the result's generalizability by selecting respondents from a wider spectrum of respondents.