• Journal of Global Scholars of Marketing Science
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• v.18 no.1
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• pp.141-156
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• 2008

Market structure analysis is a very useful tool to analyze the competition boundary of the brand or the company. But most of the studies in market structure analysis, the concern lies in nondurable goods such as candies, soft drink and etc. because of the their availability of the data. In the field of durable goods, the limitation of the data availability and the repurchase time period constrain the study. In the analysis of the automobile market, those of views might be more persuasive. The purpose of this study is to analyze the structure of automobile market based on some idea suggested by prior studies. Usually the buyers of the automobile tend to buy upper tier when they buy in the next time. That kind of behavior make it impossible to analyze the structure of automobile market under the level of automobile model. For that reason I tried to analyze the market structure in the brand or company level. In this study, consideration data was used for market structure analysis. The reasons why we used the consideration data are summarized as following. Firstly, as the repurchase time cycle is too long, brand switching data which is used for the market analysis of nondurable good is not avaliable. Secondly, as we mentioned, the buyers of the automobile tend to buy upper tier when they buy in the next time. We used survey data collected in the U.S.A. market in the year of 2005 through questionaire. The sample size was 8,291. The number of brand analyzed in this study was 9 among 37 which was being sold in U.S.A. market. Their market share was around 50%. The brands considered were BMW, Chevrolet, Chrysler, Dodge, Ford, Honda, Mercedes, and Toyota. �� ratio was derived from frequency of the consideration set. Actually the frequency is different from the brand switch concept. In this study to compute the �� ratio, the frequency of the consideration set was used like a frequency of brand switch for convenience. The study can be divided into 2 steps. The first step is to build hypothetical market structures. The second step is to choose the best structure based on the hypothetical market structures, Usually logit analysis is used for the choice best structure. In this study we built 3 hypothetical market structure. They are type-cost, cost-type, and unstructured. We classified the automobile into 5 types, sedan, SUV(Sport Utility Vehicle), Pickup, Mini Van, and Full-size Van. As for purchasing cost, we classified it 2 groups based on the median value. The median value was $28,800. To decide best structure among them, maximum likelihood test was used. Resulting from market structure analysis, we find that the automobile market of USA is hierarchically structured in the form of 'automobile type - purchasing cost'. That is, result showed that automobile buyers considered function or usage first and purchasing cost next. This study has some limitations in the analysis level and variable selection. First, in this study only type of the automobile and purchasing cost were as attributes considered for purchase. Considering other attributes is very needful. Because of the attributes considered, only 3 hypothetical structure could be analyzed. Second, due to the data, brand level analysis was tried. But model level analysis would be better because automobile buyers consider model not brand. To conduct model level study more cases should be obtained. That is for acquiring the better practical meaning, brand level analysis should be conducted when we consider the actual competition which occurred in the real market. Third, the variable selection for building nested logit model was very limited to some avaliable data. In spite of those limitations, the importance of this study lies in the trial of market structure analysis of durable good.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.3
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• pp.195-203
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• 2013

In this study, antioxidative effects of the extracts of different species and flowering periods of Inula britannica were investigated. According to the free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity of the extracts, The I. britannica var. chinensis flower extract (500 ${\mu}g/mL$) was measured in a 79.89% free radical scavenging activity, but the flower extracts of similar species (I. britannica var. linariaefolia Regel, I. britannica var. ramosa, I. salicina var. asiatica) did not show any effect on the free radical scavenging activity. The effects of the free radical scavenging activity of I. britannica var. chinensis flower extracts were exhibited in the order of full bloom (93.68%), bud (43.28%), and fallen blossom (14.11%). Next, we established optimum condition of extract solvent, temperature, extraction time. The extract from ethanol at $60^{\circ}C$ showed the most free radical scavenging activity among other conditions and extraction time not relevant in free radical scavenging activity. The protective effects of the extract of I. britannica var. chinensis flower on the photohemolysis of human erythrocytes by using rose bengal were increased in a concentration-dependent manner (5 ~ 50 ${\mu}g/mL$). In particular, the extract in 50 ${\mu}g/mL$ concentration exhibited better protective activity (${\tau}_{50}$ = 116.1 min) than (+)-${\alpha}$-tocopherol (${\tau}_{50}$ = 73.44 min), which is a known lipophilic antioxidant. Principle component of I. britannica var. chinensis flower was identified as quercetin of flavonoids by high-performance liquid chromatography (HPLC). These results indicate that the extract of I. britannica var. chinensis flower can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging free radical and $^1O_2$, and protect cellular membranes against ROS. It is concluded that the antioxidative effects of the extract of I. britannica var. chinensis flower could be applicable to functional cosmetics.

• Korean journal of applied entomology
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• v.50 no.4
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• pp.343-352
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• 2011

The developmental period of Laodelphax striatellus Fallen, a vector of rice stripe virus (RSV), was investigated at ten constant temperatures from 12.5 to $35{\pm}1^{\circ}C$ at 30 to 40% RH, and a photoperiod of 14:10 (L:D) h. Eggs developed successfully at each temperature tested and their developmental time decreased as temperature increased. Egg development was fasted at $35^{\circ}C$(5.8 days), and slowest at $12.5^{\circ}C$ (44.5 days). Nymphs could not develop to the adult stage at 32.5 or $35^{\circ}C$. The mean total developmental time of nymphal stages at 12.5, 15, 17.5, 20, 22.5, 25, 27.5 and $30^{\circ}C$ were 132.7, 55.9, 37.7, 26.9, 20.2, 15.8, 14.9 and 17.4 days, respectively. One linear model and four nonlinear models (Briere 1, Lactin 2, Logan 6 and Poikilotherm rate) were used to determine the response of developmental rate to temperature. The lower threshold temperatures of egg and total nymphal stage of L. striatellus were $10.2^{\circ}C$ and $10.7^{\circ}C$, respectively. The thermal constants (degree-days) for eggs and nymphs were 122.0 and 238.1DD, respectively. Among the four nonlinear models, the Poikilotherm rate model had the best fit for all developmental stages ($r^2$=0.98~0.99). The distribution of completion of each development stage was well described by the two-parameter Weibull function ($r^2$=0.84~0.94). The emergence rate of L. striatellus adults using DYMEX$^{(R)}$ was predicted under the assumption that the physiological age of over-wintered nymphs was 0.2 and that the Poikilotherm rate model was applied to describe temperature-dependent development. The result presented higher predictability than other conditions.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.3 no.2
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• pp.213-233
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• 1996

This study was made on 274 apoplectics patients who received the rehabilitation therapy and tests on physical, psychological and social adaptations as outpatients in 23 general hospitals in the Seoul and Kyungi area. The basic data on degree of improvement of apoplectic patients studied from rehabilitation therapy. Data was collected over a period of 63 days, from February 21st till April, 23, 1996. The assigned physical therapist conducted direct interviews with patients after he answered the distributed questionnaires for each individual patient. The colleted data was processed by the $SPCC/C^+$ method. The results of the tests conducted to meascne the the degree of ADL dependency, depression and social activity corresponding to the physical, psychological, and social adaptation. The details are ; 1) The test to meascne the degree of ADL dependency, corresponding to the study of physical adaptation of CVA patients, indicated a mean score of 2.57(ideal score is 1.0) with a standard deviation of ${\pm}0.75$. The worst score was 3.95 while the best score was a perfect 1.0, representing a severe range of dependency. The distribution was centered with a median of 2.65 and a mode of 2.68. 2) The test to meascne the degree of depression which corresponds to the level of psychological adaptation yielded a mean of 2.99 which is higher than the normal limit of 2.45. The standard deviation was ${\pm}0.52$ and the worst score and the best score were 4.35 and Respectirdy. The distribution was centered with a median of 3.00 and a mode of 3.00. 3) The test to meascne the degree of social activities for the level of social adaptation indicated a very low mean score of 26.52 (perfect score is 144), with the standard deviation of ${\pm}16.23$. Some patients scored as high as 100, but others scored as low as 3. The distribution of social activities at a very low level was shifted to the left with a median of 24.00 and a mode of 20.00. 4) Factors influencing the level of physical, psychological and social adaptation are as follows : Factors significantly influencing the level of physical adaptation measured by ADL dependency are age, personal guardian, payer of medical expenses, and paralysis of the right arm, right leg and facial paralysis. Factors significantly influencing the level of psychological adaptation measured by the degree of depression, are age, marital status, education, medical history of individual and family, speech impediment, and facial paralysis. Factors significantly influencing the level of social adaptation measured by the degree of social activity are age, marital status, education, employment status, and the burden of medical expense. 5) The Corelationship is significant(9.00), between ADL dependeing as degree of physical adaptation and depreseion as degree of psychologial adaptation. ADL dependency is proportional to depression. But social activity is inversely protional to ADL dependeny and depression. In conclusion, the increased care for physical function of the patients is not the only necessary means to better facilitate the appropriate adaptation of CVA patients. The introduction of a solid rehabilitation program for psychological and social adaptation will also play the integral part of the treatment of CVA patients.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.2
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• pp.155-188
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• 2017

On the one hand, the 4th Industrial Revolution provides a positive opportunity to build a new civilization paradigm for mankind. However, on the other hand, due to the 4th Industrial Revolution, artificial intelligence such as 'Goggle Alpha Go' revolutionized and even the human ability was replaced with a 'Silicon Chip' as the opportunity to communicate decreases, the existence of human beings is weakened. And there is a growing concern that the number of violent crimes, such as psychopath, which hunts humans as games, will increase. Moreover, recent international terrorism is being developed in a form similar to 'Psychopathic Violent-Crime' that indiscriminately attacks innocent people. So, the probability that terrorist organizations abuse the positive effects provided by the Fourth Industrial Revolution as means of terrorism is increasing. Therefore, the paradigm of aviation terrorism is expected to change in a way that attacks airport facilities and users rather than aircraft. Because airport facilities are crowded, and psychopathic terrorists are easily accessible. From this point of view, our counter terrorism system of aviation has many weak points in various aspects such as: (1) limitations of counter-terrorism center (2) inefficient on-site command and control system (3) separated organization for aviation security consultation (4) dispersed information collection function in government (5) vulnerable to cyber attack (6) lack of international cooperation network for aviation terrorism. Consequently, it is necessary to improve the domestic counter terrorism system of aviation so as to preemptively respond to the international terrorism. This study propose the following measures to improve the aviation security system by (1) create 'Aviation Special Judicial Police' (2) revise the anti-terrorism law and aviation security law (3) Strengthening the ability respond to terrorism in cyberspace (4) building an international cooperation network for aviation terrorism.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.2
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• pp.141-147
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• 2011

The aim of this study was to evaluate histomorphometrically and compare the efficiency of various bone graft material and autogenous tooth bone graft material which were used in sinus bone graft procedure. Subjects were the 24 patients who had treated with sinus bone graft using lateral approach from October 2007 to September 2009 at SNUBH. The average age was $52.51{\pm}11.86$ years. All cases was taken after 4month of procedure and divided into 3 groups according to bone graft material. Group 1: autogenous tooth bone graft material, Group 2: OrthoblastII(integra lifescience corp. Irvine, US)+Biocera(Osscotec, seoul, korea), group 3: DBX(Synthes, USA)+BioOss(Geistlich Pharm AG, Wolhusen, Switzerland). Total 37 implant placement area were included and evaluated(7 in group 1, 10 in group 2, 20 in group 3). Evaluation of new bone formation, ratio of woven bone to lamellar bone, ratio of new bone to graft material were performed on each tissue section. Kruskal-Wallis test was used for statistical analysis(SPSS Ver. 12.0, USA). New bone formation were $52.5{\pm}10.7%$ in group 1, $52.0{\pm}23.4%$ in group 2, $51.0{\pm}18.3%$ in group 3. There were no statistical significant differences between each groups. Ratio of woven bone to lamella bone were $82.8{\pm}15.3%$ in group 1, $36.7{\pm}59.3%$ in group 2, $31.0{\pm} 51.2%$ in group 3. Ratio of new bone to graft material were $81.3{\pm}10.4%$ in group 1, $72.5{\pm}28.8%$ in group 2, $80.3{\pm}24.0%$ in group 3. After 4 month of healing period, all group showed favorable new bone formation and around graft material and implant. Within limitation of our study, it is suggested that autogenous tooth bone graft material might be used as novel bone graft material for sinus bone graft.

• Journal of the Korean association of regional geographers
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• v.4 no.1
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• pp.15-25
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• 1998

A stream plays an important role as the source of drinking water, the ecological space and the living space. But the today's urban stream whose ecosystem is destroyed and water quality become worse in consequence of covering, concrete dyke construction, and the adjustment of high-water-ground[dunchi], is deprived of the function as a stream. Therefore this paper aims to elucidate the role that urban stream plays ecologically and to try to find a improvement to the problem. A stream is the pathway through which several types of the solar radiation energy are transmitted and the place which is always full of life energy. In the periphery of a stream, primary productivity is high and carrying capacity of population is great. Thus ancient cities based on agricultural products grew out of the fertile surroundings of stream. In Korea most cities of the Chosen Dynasty Period based on the agriculture have grown out of the erosional basins where solar energy is concentrated. The role of a stream in this agricultural system is the source of energy and material(water and sediment) and a lifeline. In consequence of the growth of cities and the rapid growing demands of water supply after the Industrial Revolution, a stream has become a more important locational factor of city. However, because cities need the life energy of urban streams no longer, urban streams cannot play role as a lifeline. And As pollutant waste water has poured into urban streams after using external streams' water, urban streams have degraded to the status of a ditch. As the results of the progress of urbanization, the dangerousness of inundation of urban stream increased and its water quality became worse. For the sake of holding back it, local governments constructed concrete dyke, adjusted high-water-ground[dunchi], and covered the channel. But stream ecosystem went to ruin and its water quality became much worse after channelization. These problems of urban stream can be solved by transmitting much energy contained in stream to land ecosystem as like rural stream. We should dissipate most of the energy contained in urban stream by cultivating wetland vegetation from the shore of stream to high-water-ground, and should recover a primitive natural vigorous power by preparation of ecological park.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.189-198
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• 2009

Purpose: We wanted to evaluate the clinical results of the Latarjet procedure for treating anterior shoulder instability combined with a glenoid bone defect. Materials and Methods: Between Oct. 2006 and May. 2007, fourteen patients underwent a Latarjet operation to treat their anterior shoulder instability combined with a glenoid bone defect. The mean follow-up period was 15 months (range: 12 to 19 months), and the average age at the time of surgery was 29.9-years-old (range: 19 to 44 years). There were 13 males and 1 female. Eight patients exhibited involvement of the right shoulder. The dominant arm was involved in 8 patients. Six patients had undergone a previous arthroscopic Bankart repair before their Latarjet operation and 2 patients had a history of seizure. Results: The average Rowe score improved from 51.8 to 80.2 with 9 excellent, 4 good, and 1 fair results. The average Korean shoulder score for instability improved from 61.6 to 82.1 postoperatively. The active forward flexion and external rotation at the side of the involved shoulder was an average of $8^{\circ}$ and $16^{\circ}$ less than that of the uninvolved shoulder. The muscle strength of the involved shoulder measured 78.7% in forward flexion and 82.5% in external rotation, as compared with that of the uninvolved shoulder. There was 1 case of dislocation, 1 transient subluxation, 2 fibrotic unions, 1 resorption of the transferred coracoid process, 1 intraoperative broken bone, 1 transient musculocutaneous nerve injury and 1 case of stiffness. Conclusion: The Latarjet procedure for treating anterior shoulder instability combined with a significant glenoid defect effectively restores function and stability through extending the articular arc at the expense of external rotation. We should be cautious to avoid or detect complications when performing coracoid transfer.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.150-158
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• 2009

Purpose: With the better understanding of cuff function, partial repair or "force couple repair" for treating massive irreparable rotator cuff tear has gained some popularity. However, there were few reports on the results of partial repair. The purpose of this study was to report the clinical outcome of massive irreparable rotator cuff tears who received arthroscopic force-couple repair or partial repair. Materials and Methods: From June 2005 to Feb 2008, arthroscopic partial repairs were performed for 16 irreparable rotator cuff tears among the 101 large to massive rotator cuff tears that were operated on. Clinical and radiographic evaluation were done at the final follow-up. Results: There were 7 men and 9 women with a mean age of 66.6 years. The mean follow-up period was 27.3 month (range: 15-46). The pain VAS improved from 4.4 ($\pm2.50$) to 2.1 ($\pm2.26$) and the functional VAS improved from 46.9 ($\pm16.64$) to 70.0 ($\pm22.80$). The ASES score improved from 39.0 ($\pm10.80$) to 80.3 ($\pm16.78$) and the KSS score was 81.9 ($\pm16.74$) at the final follow-up. The acromio-humeral distance was 6.6 cm ($\pm1.74$) preoperatively and 6.2 cm ($\pm1.69$) postoperatively without significant change (p=0.3874). The degenerative changes had no statistically progressed (p=0.2663). Conclusion: Partial repair for massive rotator cuff injury patients showed improvement in the clinical score without progression of arthritic change at a mean of 2.3 years follow-up.

• Economic and Environmental Geology
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• v.44 no.6
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• pp.485-492
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• 2011

Sorption of cyanide on granular activated carbon and attenuation of the cyanide by UV-light over a wide range of conditions such as pH and concentration were investigated through batch experiments. Cyanide uptake by activated carbon is much effective at $[CN]_{ini}$ < 2 mg/L. The sorption of cyanide on activated carbon at pH 7.0 is greater than that of pH 9.0. It is found that the ratio of CN uptake to CN in solution increases at pH 9.0 whereas at pH 7.0 the ratio decreases, suggesting that reactivity of activated carbon increases as a function of pH. The sorption of cyanide rapidly increases during the first 30 min, followed by sharp desorption until 3hr, and then the sorption increases and reaches the maximum sorption during the duration of experiments, implying that the sorption mode could be changed through conformational change during the initial stage of the cyanide uptake by activated carbon. Total amount of cyanide desorbed from the activated carbon during the period of desorption experiments is less than 1.5% of total sorbed cyanide, indicative of strong and stable sorption of cyanide on the activated carbon. The sorption with mixture of activated carbon and Ham-Baek sludge shows less effective on the removal of the cyanide. It is noted that UV-light is much effective on the removal of cyanide but also the attenuation is achieved until $[CN]_{tot}$ is up to 10 mg/L. Our findings demonstrate that both activated carbon and UV-light are very effective on the attenuation of cyanide over a wide range of environmental conditions.