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A Study on the Characteristics of Enterprise R&D Capabilities Using Data Mining (데이터마이닝을 활용한 기업 R&D역량 특성에 관한 탐색 연구)

  • Kim, Sang-Gook;Lim, Jung-Sun;Park, Wan
    • Journal of Intelligence and Information Systems
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    • v.27 no.1
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    • pp.1-21
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    • 2021
  • As the global business environment changes, uncertainties in technology development and market needs increase, and competition among companies intensifies, interests and demands for R&D activities of individual companies are increasing. In order to cope with these environmental changes, R&D companies are strengthening R&D investment as one of the means to enhance the qualitative competitiveness of R&D while paying more attention to facility investment. As a result, facilities or R&D investment elements are inevitably a burden for R&D companies to bear future uncertainties. It is true that the management strategy of increasing investment in R&D as a means of enhancing R&D capability is highly uncertain in terms of corporate performance. In this study, the structural factors that influence the R&D capabilities of companies are explored in terms of technology management capabilities, R&D capabilities, and corporate classification attributes by utilizing data mining techniques, and the characteristics these individual factors present according to the level of R&D capabilities are analyzed. This study also showed cluster analysis and experimental results based on evidence data for all domestic R&D companies, and is expected to provide important implications for corporate management strategies to enhance R&D capabilities of individual companies. For each of the three viewpoints, detailed evaluation indexes were composed of 7, 2, and 4, respectively, to quantitatively measure individual levels in the corresponding area. In the case of technology management capability and R&D capability, the sub-item evaluation indexes that are being used by current domestic technology evaluation agencies were referenced, and the final detailed evaluation index was newly constructed in consideration of whether data could be obtained quantitatively. In the case of corporate classification attributes, the most basic corporate classification profile information is considered. In particular, in order to grasp the homogeneity of the R&D competency level, a comprehensive score for each company was given using detailed evaluation indicators of technology management capability and R&D capability, and the competency level was classified into five grades and compared with the cluster analysis results. In order to give the meaning according to the comparative evaluation between the analyzed cluster and the competency level grade, the clusters with high and low trends in R&D competency level were searched for each cluster. Afterwards, characteristics according to detailed evaluation indicators were analyzed in the cluster. Through this method of conducting research, two groups with high R&D competency and one with low level of R&D competency were analyzed, and the remaining two clusters were similar with almost high incidence. As a result, in this study, individual characteristics according to detailed evaluation indexes were analyzed for two clusters with high competency level and one cluster with low competency level. The implications of the results of this study are that the faster the replacement cycle of professional managers who can effectively respond to changes in technology and market demand, the more likely they will contribute to enhancing R&D capabilities. In the case of a private company, it is necessary to increase the intensity of input of R&D capabilities by enhancing the sense of belonging of R&D personnel to the company through conversion to a corporate company, and to provide the accuracy of responsibility and authority through the organization of the team unit. Since the number of technical commercialization achievements and technology certifications are occurring both in the case of contributing to capacity improvement and in case of not, it was confirmed that there is a limit in reviewing it as an important factor for enhancing R&D capacity from the perspective of management. Lastly, the experience of utility model filing was identified as a factor that has an important influence on R&D capability, and it was confirmed the need to provide motivation to encourage utility model filings in order to enhance R&D capability. As such, the results of this study are expected to provide important implications for corporate management strategies to enhance individual companies' R&D capabilities.

The Influence of Store Environment on Service Brand Personality and Repurchase Intention (점포의 물리적 환경이 서비스 브랜드 개성과 재구매의도에 미치는 영향)

  • Kim, Hyoung-Gil;Kim, Jung-Hee;Kim, Youn-Jeong
    • Journal of Global Scholars of Marketing Science
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    • v.17 no.4
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    • pp.141-173
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    • 2007
  • The study examines how the environmental factors of store influence service brand personality and repurchase intention in the service environment. The service industry has been experiencing the intensified competition with the industry's continuous growth and the influence from rapid technological advancement. Under the circumstances, it has become ever more important for the brand competitiveness to be distinctively recognized against competition. A brand needs to be distinguished and differentiated from competing companies because they are all engaged in the similar environment of the service industry. The differentiation of brand achievement has become increasingly important to highlight certain brand functions to include emotional, self-expressive, and symbolic functions since the importance of such functions has been further emphasized in promoting consumption activities. That is the recent role of brand personality that has been emphasized in the service industry. In other words, customers now freely and actively express their personalities or egos in consumption activities, taking an important role in construction of a brand asset. Hence, the study suggests that it is necessary to disperse the recognition and acknowledgement that the maintenance of the existing customers contributes more to boost repurchase intention when it is compared to the efforts to create new customers, particularly in the service industry. Meanwhile, the store itself can offer a unique environment that may influence the consumer's purchase decision. Consumers interact with store environments in the process of,virtually, all household purchase they make (Sarel 1981). Thus, store environments may encourage customers to purchase. The roles that store environments play are to provide informational cues to customers about the store and goods and communicate messages to stimulate consumers' emotions. The store environments differentiate the store from competing stores and build a unique service brand personality. However, the existing studies related to brand in the service industry mostly concentrated on the relationship between the quality of service and customer satisfaction, and they are mostly generalized while the connective studies focused on brand personality. Such approaches show limitations and are insufficient to investigate on the relationship between store environment and brand personality in the service industry. Accordingly, the study intends to identify the level of contribution to the establishment of brand personality made by the store's physical environments that influence on the specific brand characteristics depending on the type of service. The study also intends to identify what kind of relationships with brand personality exists with brand personality while being influenced by store environments. In addition, the study intends to make meaningful suggestions to better direct marketing efforts by identifying whether a brand personality makes a positive influence to induce an intention for repurchase. For this study, the service industry is classified into four categories based on to the characteristics of service: experimental-emotional service, emotional -credible service, credible-functional service, and functional-experimental service. The type of business with the most frequent customer contact is determined for each service type and the enterprise with the highest brand value in each service sector based on the report made by the Korea Management Association. They are designated as the representative of each category. The selected representatives are a fast-food store (experimental-emotional service), a cinema house (emotional-credible service), a bank (credible-functional service), and discount store (functional-experimental service). The survey was conducted for the four selected brands to represent each service category among consumers who are experienced users of the designated stores in Seoul Metropolitan City and Gyeonggi province via written questionnaires in order to verify the suggested assumptions in the study. In particular, the survey adopted 15 scales, which represent each characteristic factor, among the 42 unique characteristics developed by Jennifer Aaker(1997) to assess the brand personality of each service brand. SPSS for Windows Release 12.0 and LISREL were used in the analysis of data verification. The methodology of the structural equation model was used for the study and the pivotal findings are as follows. 1) The environmental factors ware classified as design factors, ambient factors, and social factors. Therefore, the validity of measurement scale of Baker et al. (1994) was proved. 2) The service brand personalities were subdivided as sincerity, excitement, competence, sophistication, and ruggedness, which makes the use of the brand personality scales by Jennifer Aaker(1997) appropriate in the service industry as well. 3) One-way ANOVA analysis on the scales of store environment and service brand personality showed that there exist statistically significant differences in each service category. For example, the social factors were highest in discount stores, while the ambient factors and design factors were highest in fast-food stores. The discount stores were highest in the sincerity and excitement, while the highest point for banks was in the competence and ruggedness, and the highest point for fast-food stores was in the sophistication, The consumers will make a different respond to the physical environment of stores and service brand personality that are inherent to the corresponding service interface. Hence, the customers will make a different decision-making when dealing with different service categories. In this aspect, the relationships of variables in the proposed hypothesis appear to work in a different way depending on the exposed service category. 4) The store environment factors influenced on service brand personalities differently by category of service. The factors of store's physical environment are transferred to a brand and were verified to strengthen service brand personalities. In particular, the level of influence on the service brand personality by physical environment differs depending on service category or dimension, which indicates that there is a need to apply a different style of management to a different service category or dimension. It signifies that there needs to be a brand strategy established in order to positively influence the relationship with consumers by utilizing an appropriate brand personality factor depending on different characteristics by service category or dimension. 5) The service brand personalities influenced on the repurchase intention. Especially, the largest influence was made in the sophistication dimension of service brand personality scale; the unique and characteristically appropriate arrangement of physical environment will make customers stay in the service environment for a long time and will lead to give a positive influence on the repurchase intention. 6) The store environment factors influenced on the repurchase intention. Particularly, the largest influence was made on the social factors of store environment. The most intriguing finding is that the service factor among all other environment factors gives the biggest influence to the repurchase intention in most of all service types except fast-food stores. Such result indicates that the customers pay attention to how much the employees try to provide a quality service when they make an evaluation on the service brand. At the same time, it also indicates that the personal factor is directly transmitted to the construction of brand personality. The employees' attitude and behavior are the determinants to establish a service brand personality in the process of enhancing service interface. Hence, there should be a reinforced search for a method to efficiently manage the service staff who has a direct contact with customers in order to make an affirmative improvement of the customers' brand evaluation at the service interface. The findings suggest several managerial implications. 1) Results from the empirical study indicated that store environment factors have a strong positive impact on a service brand personality. To increase customers' repurchase intention of a service brand, the management is required to effectively manage store environment factors and create a friendly brand personality based on the corresponding service environment. 2) Mangers and researchers must understand and recognize that the store environment elements are important marketing tools, and that brand personality influences on consumers' repurchase intention. Based on such result of the study, a service brand could be utilized as an efficient measure to achieve a differentiation by enforcing the elements that are most influential among all other store environments for each service category. Therefore, brand personality established involving various store environments will further reinforce the relationship with customers through the elevated brand identification of which utilization to induce repurchase decision can be used as an entry barrier. 3) The study identified the store environment as a component of service brand personality for the store's effective communication with consumers. For this, all communication channels should be maintained with consistency and an integrated marketing communication should be executed to efficiently approach to a larger number of customers. Mangers and researchers must find strategies for aligning decisions about store environment elements with the retailers' marketing and store personality objectives. All ambient, design, and social factors need to be orchestrated so that consumers can take an appropriate store personality. In this study, the induced results from the previous studies were extended to the service industry so as to identify the customers' decision making process that leads to repurchase intention and a result similar to those of the previous studies. The findings suggested several theoretical and managerial implications. However, the situation that only one service brand served as the subject of analysis for each service category, and the situation that correlations among store environment elements were not identified, as well as the problem of representation in selection of samples should be considered and supplemented in the future when further studies are conducted. In addition, various antecedents and consequences of brand personality must be looked at in the aspect of the service environment for further research.

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Normative blood pressure references for Korean children and adolescents (한국 소아 청소년 정상 혈압 참고치)

  • Lee, Chong Guk;Moon, Jin Soo;Choi, Joong-Myung;Nam, Chung Mo;Lee, Soon Young;Oh, Kyungwon;Kim, Young Taek
    • Clinical and Experimental Pediatrics
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    • v.51 no.1
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    • pp.33-41
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    • 2008
  • Purpose : It is now understood that blood pressure (BP) measurement in the routine pediatric examination is very important because of the relevance of childhood BP to pediatric health care and the development of adult essential hypertension. There hasn't been a reference table of BP for Korean children and adolescents up to now. This study was to make normative BP references and to provide criteria of hypertension for Korean children and adolescents. Methods : BP measurements were done on 57,433 Koean children and adolescents (male: 29,443, female: 27,990), aged 7 to 20 years, in 2005. Heights and weights were measured simultaneously. Oscillometric devices, Dinamap Procare 200 (GE Inc., Milwaukee, Wi, USA), were used for the measurements. BPs were measured 2 times and mean levels were gathered for the analysis. Outliers of 2,373 subjects with overweight per height, over +3SD, were excluded for the analysis. For the BP centiles adjusted by sex, age and height, fixed modified LMS method which was adopted from the mixed effect model of 2004 Task Force in NHLBI (USA) was used. Results : Normative BP tables for Korean children and adolescents adjusted for height percentiles (5th, 10th, 25th, 50th, 75th, 90th, 95th), gender (male, female) and age(7 to 18 years) were completed. Height centiles of Korean children and adolescents are available from Korean Center for Disease Control and Prevention homepage, http://www.cdc.go.kr/webcdc/. Criteria of hypertension (95th, 99th percentile) and normal range of BP (50th, 90th) adjusted for height percentiles, age and gender were made. Conclusion : This is the first study to make normative BP tables and define hypertension for the Korean children and adolescents. Reliability and accuracy of Dinamap Procare 200 oscillometer for BP measurements remains debatable.

Effects of an intensive asthma education program on asthmatic children and their caregivers (천식 환아와 보호자를 대상으로 한 집중 교육 프로그램의 효과)

  • Seo, Kang Jin;Kim, Gun Ha;Yu, Byung Keun;Yeo, Yun Ku;Kim, Jong Hoon;Shim, Eu Ddeum;Yoon, Mi Ri;Yoo, Young;Choung, Ji Tae
    • Clinical and Experimental Pediatrics
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    • v.51 no.2
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    • pp.188-203
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    • 2008
  • Purpose : Asthma is one of the most common chronic childhood disease. Education of asthmatic children and their families about asthma and its management may improve disease control, reduce symptoms, and improve school performance. The aim of the study was to evaluate the effects of an intensive asthma education program in asthmatic children and their families on outcome measure of asthma management behavior scale, knowledge about asthma, self efficacy scale and quality of life. Methods : Fifteen asthmatic children and their families were invited the intensive asthma education program which including allergen avoidance, management of asthma, correct use of the inhalation devices and control of exercise-induced asthma (study group). Fifteen asthmatic children and their families those who did not participate this program were served as control group. Participants were asked to complete a written questionnaire before and 3-month after the program. Results : After completing the intensive education program, significant improvement of the childrens asthma management behavior scale (27.1 vs. 32.2, P=0.011), belief and knowledge about asthma (14.2 vs. 17.9, P<0.001), self efficacy (47.9 vs. 49.7, P=0.091) and quality of life (79.6 vs. 88.6, P<0.001) was noted in the study group by measuring questionnaires. There are increasing tendencies in parental asthma management behavior scale and knowledge about asthma. Conclusion : This intensive asthma education program is effective in improving asthma control, self efficacy and quality of life of asthmatic children. This should serve as a national model for family-based programs for asthmatic children and their families.

Analysis and Evaluation of Frequent Pattern Mining Technique based on Landmark Window (랜드마크 윈도우 기반의 빈발 패턴 마이닝 기법의 분석 및 성능평가)

  • Pyun, Gwangbum;Yun, Unil
    • Journal of Internet Computing and Services
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    • v.15 no.3
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    • pp.101-107
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    • 2014
  • With the development of online service, recent forms of databases have been changed from static database structures to dynamic stream database structures. Previous data mining techniques have been used as tools of decision making such as establishment of marketing strategies and DNA analyses. However, the capability to analyze real-time data more quickly is necessary in the recent interesting areas such as sensor network, robotics, and artificial intelligence. Landmark window-based frequent pattern mining, one of the stream mining approaches, performs mining operations with respect to parts of databases or each transaction of them, instead of all the data. In this paper, we analyze and evaluate the techniques of the well-known landmark window-based frequent pattern mining algorithms, called Lossy counting and hMiner. When Lossy counting mines frequent patterns from a set of new transactions, it performs union operations between the previous and current mining results. hMiner, which is a state-of-the-art algorithm based on the landmark window model, conducts mining operations whenever a new transaction occurs. Since hMiner extracts frequent patterns as soon as a new transaction is entered, we can obtain the latest mining results reflecting real-time information. For this reason, such algorithms are also called online mining approaches. We evaluate and compare the performance of the primitive algorithm, Lossy counting and the latest one, hMiner. As the criteria of our performance analysis, we first consider algorithms' total runtime and average processing time per transaction. In addition, to compare the efficiency of storage structures between them, their maximum memory usage is also evaluated. Lastly, we show how stably the two algorithms conduct their mining works with respect to the databases that feature gradually increasing items. With respect to the evaluation results of mining time and transaction processing, hMiner has higher speed than that of Lossy counting. Since hMiner stores candidate frequent patterns in a hash method, it can directly access candidate frequent patterns. Meanwhile, Lossy counting stores them in a lattice manner; thus, it has to search for multiple nodes in order to access the candidate frequent patterns. On the other hand, hMiner shows worse performance than that of Lossy counting in terms of maximum memory usage. hMiner should have all of the information for candidate frequent patterns to store them to hash's buckets, while Lossy counting stores them, reducing their information by using the lattice method. Since the storage of Lossy counting can share items concurrently included in multiple patterns, its memory usage is more efficient than that of hMiner. However, hMiner presents better efficiency than that of Lossy counting with respect to scalability evaluation due to the following reasons. If the number of items is increased, shared items are decreased in contrast; thereby, Lossy counting's memory efficiency is weakened. Furthermore, if the number of transactions becomes higher, its pruning effect becomes worse. From the experimental results, we can determine that the landmark window-based frequent pattern mining algorithms are suitable for real-time systems although they require a significant amount of memory. Hence, we need to improve their data structures more efficiently in order to utilize them additionally in resource-constrained environments such as WSN(Wireless sensor network).

Verification of Gated Radiation Therapy: Dosimetric Impact of Residual Motion (여닫이형 방사선 치료의 검증: 잔여 움직임의 선량적 영향)

  • Yeo, Inhwan;Jung, Jae Won
    • Progress in Medical Physics
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    • v.25 no.3
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    • pp.128-138
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    • 2014
  • In gated radiation therapy (gRT), due to residual motion, beam delivery is intended to irradiate not only the true extent of disease, but also neighboring normal tissues. It is desired that the delivery covers the true extent (i.e. clinical target volume or CTV) as a minimum, although target moves under dose delivery. The objectives of our study are to validate if the intended dose is surely delivered to the true target in gRT and to quantitatively understand the trend of dose delivery on it and neighboring normal tissues when gating window (GW), motion amplitude (MA), and CTV size changes. To fulfill the objectives, experimental and computational studies have been designed and performed. A custom-made phantom with rectangle- and pyramid-shaped targets (CTVs) on a moving platform was scanned for four-dimensional imaging. Various GWs were selected and image integration was performed to generate targets (internal target volume or ITV) for planning that included the CTVs and internal margins (IM). The planning was done conventionally for the rectangle target and IMRT optimization was done for the pyramid target. Dose evaluation was then performed on a diode array aligned perpendicularly to the gated beams through measurements and computational modeling of dose delivery under motion. This study has quantitatively demonstrated and analytically interpreted the impact of residual motion including penumbral broadening for both targets, perturbed but secured dose coverage on the CTV, and significant doses delivered in the neighboring normal tissues. Dose volume histogram analyses also demonstrated and interpreted the trend of dose coverage: for ITV, it increased as GW or MA decreased or CTV size increased; for IM, it increased as GW or MA decreased; for the neighboring normal tissue, opposite trend to that of IM was observed. This study has provided a clear understanding on the impact of the residual motion and proved that if breathing is reproducible gRT is secure despite discontinuous delivery and target motion. The procedures and computational model can be used for commissioning, routine quality assurance, and patient-specific validation of gRT. More work needs to be done for patient-specific dose reconstruction on CT images.

Relationship between Bone Morphological Microstructure and Inflammatory Markers in Growing Mice Fed a High Fat Diet (고지방식이 공급에 따른 성장기 마우스의 골의 형태학적 미세구조와 염증지표 변화)

  • Kim, Mi-Sung;Lee, Hyun-A;Kim, Ok-Jin;Sohn, Cheong-Min
    • Journal of Nutrition and Health
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    • v.44 no.6
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    • pp.481-487
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    • 2011
  • Obesity not only reduces bone mineral density but also increases inflammatory markers. Therefore, we examined the change in inflammatory markers and morphological microstructure of the bones using a mouse model fed a high-fat diet. C57BL/6J 4-week-old male mice were divided into a control group (n = 6) and a experimental group (n = 6); the control group was provided with 10% Kcal fat diet, and the high-fat diet group was provided with 45% Kcal fat diet for 12 weeks using the free provision method. Blood was analyzed for inflammatory markers, and micro-computed tomography was used to measure the morphological microstructure of the femoral bone. The weight increases in the control group and high-fat diet group were $5.85{\pm}1.84g$ and $16.06{\pm}5.64g$, respectively (p < 0.01), glucose was $115.00{\pm}16.88mg/dL$ and $188.33{\pm}13.29mg/dL$ (p < 0.01), and triglycerides were $65.00{\pm}6.19mg/dL$ and $103.33{\pm}8.02mg/dL$ (p < 0.05) respectively. Leptin and interleukin (IL)-6 were significantly higher in the high-fat diet group than that in the control group (p < 0.01). As a result of a biochemical index analysis of bone metabolism, osteocalcin tended to be lower in the high-fat diet group, whereas CTx was significantly higher in the high-fat diet group compared to that in the control group (p < 0.01). The thickness of the bony trabecula was significantly narrower in the high-fat diet group than that in the control group (p < 0.05), and the gap in the bony trabecula was significantly wider in the high-fat diet group than that in the control group (p < 0.05). IL-6 and the gap in the bone trabecula, which was a morphological microstructure of the bones, showed a positive correlation (p < 0.05). Taken together, inducing obesity through a high-fat diet in mice during the growth phase caused a change in bone microstructure and was correlated with the inflammation index. Accordingly, restriction of excessive fat intake may be needed to suppress the inflammatory reactions and promote normal bone formation.

A Study on Characteristics of Lincomycin Degradation by Optimized TiO2/HAP/Ge Composite using Mixture Analysis (혼합물분석을 통해 최적화된 TiO2/HAP/Ge 촉매를 이용한 Lincomycin 제거특성 연구)

  • Kim, Dongwoo;Chang, Soonwoong
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.1
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    • pp.63-68
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    • 2014
  • In this study, it was found that determined the photocatalytic degradation of antibiotics (lincomycin, LM) with various catalyst composite of titanium dioxide ($TiO_2$), hydroxyapatite (HAP) and germanium (Ge) under UV-A irradiation. At first, various type of complex catalysts were investigated to compare the enhanced photocatalytic potential. It was observed that in order to obtain the removal efficiencies were $TiO_2/HAP/Ge$ > $TiO_2/Ge$ > $TiO_2/HAP$. The composition of $TiO_2/HAP/Ge$ using a statistical approach based on mixture analysis design, one of response surface method was investigated. The independent variables of $TiO_2$ ($X_1$), HAP ($X_2$) and Ge ($X_3$) which consisted of 6 condition in each variables was set up to determine the effects on LM ($Y_1$) and TOC ($Y_2$) degradation. Regression analysis on analysis of variance (ANOVA) showed significant p-value (p < 0.05) and high coefficients for determination value ($R^2$ of $Y_1=99.28%$ and $R^2$ of $Y_2=98.91%$). Contour plot and response curve showed that the effects of $TiO_2/HAP/Ge$ composition for LM degradation under UV-A irradiation. And the estimated optimal composition for TOC removal ($Y_2$) were $X_1=0.6913$, $X_2=0.2313$ and $X_3=0.0756$ by coded value. By comparison with actual applications, the experimental results were found to be in good agreement with the model's predictions, with mean results for LM and TOC removal of 99.2% and 49.3%, respectively.

Latent topics-based product reputation mining (잠재 토픽 기반의 제품 평판 마이닝)

  • Park, Sang-Min;On, Byung-Won
    • Journal of Intelligence and Information Systems
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    • v.23 no.2
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    • pp.39-70
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    • 2017
  • Data-drive analytics techniques have been recently applied to public surveys. Instead of simply gathering survey results or expert opinions to research the preference for a recently launched product, enterprises need a way to collect and analyze various types of online data and then accurately figure out customer preferences. In the main concept of existing data-based survey methods, the sentiment lexicon for a particular domain is first constructed by domain experts who usually judge the positive, neutral, or negative meanings of the frequently used words from the collected text documents. In order to research the preference for a particular product, the existing approach collects (1) review posts, which are related to the product, from several product review web sites; (2) extracts sentences (or phrases) in the collection after the pre-processing step such as stemming and removal of stop words is performed; (3) classifies the polarity (either positive or negative sense) of each sentence (or phrase) based on the sentiment lexicon; and (4) estimates the positive and negative ratios of the product by dividing the total numbers of the positive and negative sentences (or phrases) by the total number of the sentences (or phrases) in the collection. Furthermore, the existing approach automatically finds important sentences (or phrases) including the positive and negative meaning to/against the product. As a motivated example, given a product like Sonata made by Hyundai Motors, customers often want to see the summary note including what positive points are in the 'car design' aspect as well as what negative points are in thesame aspect. They also want to gain more useful information regarding other aspects such as 'car quality', 'car performance', and 'car service.' Such an information will enable customers to make good choice when they attempt to purchase brand-new vehicles. In addition, automobile makers will be able to figure out the preference and positive/negative points for new models on market. In the near future, the weak points of the models will be improved by the sentiment analysis. For this, the existing approach computes the sentiment score of each sentence (or phrase) and then selects top-k sentences (or phrases) with the highest positive and negative scores. However, the existing approach has several shortcomings and is limited to apply to real applications. The main disadvantages of the existing approach is as follows: (1) The main aspects (e.g., car design, quality, performance, and service) to a product (e.g., Hyundai Sonata) are not considered. Through the sentiment analysis without considering aspects, as a result, the summary note including the positive and negative ratios of the product and top-k sentences (or phrases) with the highest sentiment scores in the entire corpus is just reported to customers and car makers. This approach is not enough and main aspects of the target product need to be considered in the sentiment analysis. (2) In general, since the same word has different meanings across different domains, the sentiment lexicon which is proper to each domain needs to be constructed. The efficient way to construct the sentiment lexicon per domain is required because the sentiment lexicon construction is labor intensive and time consuming. To address the above problems, in this article, we propose a novel product reputation mining algorithm that (1) extracts topics hidden in review documents written by customers; (2) mines main aspects based on the extracted topics; (3) measures the positive and negative ratios of the product using the aspects; and (4) presents the digest in which a few important sentences with the positive and negative meanings are listed in each aspect. Unlike the existing approach, using hidden topics makes experts construct the sentimental lexicon easily and quickly. Furthermore, reinforcing topic semantics, we can improve the accuracy of the product reputation mining algorithms more largely than that of the existing approach. In the experiments, we collected large review documents to the domestic vehicles such as K5, SM5, and Avante; measured the positive and negative ratios of the three cars; showed top-k positive and negative summaries per aspect; and conducted statistical analysis. Our experimental results clearly show the effectiveness of the proposed method, compared with the existing method.

Experimental Study for Confirmation of Relaxation Zone in the Underground Cavity Expansion (지중 내 공동 확장에 따른 이완영역 확인을 위한 실험적 연구)

  • Kim, Youngho;Kim, Hoyeon;Kim, Yeonsam;You, Seung-Kyong;Han, Jung-Geun
    • Journal of the Korean Geosynthetics Society
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    • v.16 no.4
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    • pp.231-240
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    • 2017
  • Recently, there have been frequent occurrences of ground sink in the urban area, which have resulted in human and material damage and are accompanied by economic losses. This is caused by artificial factors such as soil loss, poor compaction, horizontal excavation due to the breakage of the aged sewage pipe, and lack of water proof at vertical excavation. The ground sink can be prevented by preliminary restoration and reinforcement through exploration, but it can be considered that it is not suitable for urgent restoration by the existing method. In this study, a model experiment was carried out to simulate the in-ground cavities caused by groundwater flow for developing non-excavation urgent restoration in underground cavity and the range of the relaxation zone was estimated by detecting the around the cavity using a relaxation zone detector. In addition, disturbance region and relaxation region were separated by injecting gypsum into cavity formed in simulated ground. The shape of the underground cavity due to the groundwater flow was similar to that of the failure mode III formed in the dense relative density ground due to water pipe breakage in the previous study. It was confirmed that the relaxed region detected using the relaxation zone detector is formed in an arch shape in the cavity top. The length ratio of the relaxation region to the disturbance region in the upper part of the cavity center is 2: 1, and it can be distinguished by the difference in the decrease of the shear resistance against the external force. In other words, it was confirmed that the secondary damage should not occur in consideration of the expandability of the material used as the injecting material in the pre-repair and reinforcement, and various ground deformation states will be additionally performed through additional experiments.