• Journal of Intelligence and Information Systems
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• v.22 no.3
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• pp.23-43
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• 2016

As a result of the growth of Internet data and the rapid development of Internet technology, "big data" analysis has gained prominence as a major approach for evaluating and mining enormous data for various purposes. Especially, in recent years, people tend to share their experiences related to their leisure activities while also reviewing others' inputs concerning their activities. Therefore, by referring to others' leisure activity-related experiences, they are able to gather information that might guarantee them better leisure activities in the future. This phenomenon has appeared throughout many aspects of leisure activities such as movies, traveling, accommodation, and dining. Apart from blogs and social networking sites, many other websites provide a wealth of information related to leisure activities. Most of these websites provide information of each product in various formats depending on different purposes and perspectives. Generally, most of the websites provide the average ratings and detailed reviews of users who actually used products/services, and these ratings and reviews can actually support the decision of potential customers in purchasing the same products/services. However, the existing websites offering information on leisure activities only provide the rating and review based on one stage of a set of evaluation criteria. Therefore, to identify the main issue for each evaluation criterion as well as the characteristics of specific elements comprising each criterion, users have to read a large number of reviews. In particular, as most of the users search for the characteristics of the detailed elements for one or more specific evaluation criteria based on their priorities, they must spend a great deal of time and effort to obtain the desired information by reading more reviews and understanding the contents of such reviews. Although some websites break down the evaluation criteria and direct the user to input their reviews according to different levels of criteria, there exist excessive amounts of input sections that make the whole process inconvenient for the users. Further, problems may arise if a user does not follow the instructions for the input sections or fill in the wrong input sections. Finally, treating the evaluation criteria breakdown as a realistic alternative is difficult, because identifying all the detailed criteria for each evaluation criterion is a challenging task. For example, if a review about a certain hotel has been written, people tend to only write one-stage reviews for various components such as accessibility, rooms, services, or food. These might be the reviews for most frequently asked questions, such as distance between the nearest subway station or condition of the bathroom, but they still lack detailed information for these questions. In addition, in case a breakdown of the evaluation criteria was provided along with various input sections, the user might only fill in the evaluation criterion for accessibility or fill in the wrong information such as information regarding rooms in the evaluation criteria for accessibility. Thus, the reliability of the segmented review will be greatly reduced. In this study, we propose an approach to overcome the limitations of the existing leisure activity information websites, namely, (1) the reliability of reviews for each evaluation criteria and (2) the difficulty of identifying the detailed contents that make up the evaluation criteria. In our proposed methodology, we first identify the review content and construct the lexicon for each evaluation criterion by using the terms that are frequently used for each criterion. Next, the sentences in the review documents containing the terms in the constructed lexicon are decomposed into review units, which are then reconstructed by using the evaluation criteria. Finally, the issues of the constructed review units by evaluation criteria are derived and the summary results are provided. Apart from the derived issues, the review units are also provided. Therefore, this approach aims to help users save on time and effort, because they will only be reading the relevant information they need for each evaluation criterion rather than go through the entire text of review. Our proposed methodology is based on the topic modeling, which is being actively used in text analysis. The review is decomposed into sentence units rather than considering the whole review as a document unit. After being decomposed into individual review units, the review units are reorganized according to each evaluation criterion and then used in the subsequent analysis. This work largely differs from the existing topic modeling-based studies. In this paper, we collected 423 reviews from hotel information websites and decomposed these reviews into 4,860 review units. We then reorganized the review units according to six different evaluation criteria. By applying these review units in our methodology, the analysis results can be introduced, and the utility of proposed methodology can be demonstrated.

• Journal of Intelligence and Information Systems
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• v.23 no.2
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• pp.123-138
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• 2017

Since the stock market is driven by the expectation of traders, studies have been conducted to predict stock price movements through analysis of various sources of text data. In order to predict stock price movements, research has been conducted not only on the relationship between text data and fluctuations in stock prices, but also on the trading stocks based on news articles and social media responses. Studies that predict the movements of stock prices have also applied classification algorithms with constructing term-document matrix in the same way as other text mining approaches. Because the document contains a lot of words, it is better to select words that contribute more for building a term-document matrix. Based on the frequency of words, words that show too little frequency or importance are removed. It also selects words according to their contribution by measuring the degree to which a word contributes to correctly classifying a document. The basic idea of constructing a term-document matrix was to collect all the documents to be analyzed and to select and use the words that have an influence on the classification. In this study, we analyze the documents for each individual item and select the words that are irrelevant for all categories as neutral words. We extract the words around the selected neutral word and use it to generate the term-document matrix. The neutral word itself starts with the idea that the stock movement is less related to the existence of the neutral words, and that the surrounding words of the neutral word are more likely to affect the stock price movements. And apply it to the algorithm that classifies the stock price fluctuations with the generated term-document matrix. In this study, we firstly removed stop words and selected neutral words for each stock. And we used a method to exclude words that are included in news articles for other stocks among the selected words. Through the online news portal, we collected four months of news articles on the top 10 market cap stocks. We split the news articles into 3 month news data as training data and apply the remaining one month news articles to the model to predict the stock price movements of the next day. We used SVM, Boosting and Random Forest for building models and predicting the movements of stock prices. The stock market opened for four months (2016/02/01 ~ 2016/05/31) for a total of 80 days, using the initial 60 days as a training set and the remaining 20 days as a test set. The proposed word - based algorithm in this study showed better classification performance than the word selection method based on sparsity. This study predicted stock price volatility by collecting and analyzing news articles of the top 10 stocks in market cap. We used the term - document matrix based classification model to estimate the stock price fluctuations and compared the performance of the existing sparse - based word extraction method and the suggested method of removing words from the term - document matrix. The suggested method differs from the word extraction method in that it uses not only the news articles for the corresponding stock but also other news items to determine the words to extract. In other words, it removed not only the words that appeared in all the increase and decrease but also the words that appeared common in the news for other stocks. When the prediction accuracy was compared, the suggested method showed higher accuracy. The limitation of this study is that the stock price prediction was set up to classify the rise and fall, and the experiment was conducted only for the top ten stocks. The 10 stocks used in the experiment do not represent the entire stock market. In addition, it is difficult to show the investment performance because stock price fluctuation and profit rate may be different. Therefore, it is necessary to study the research using more stocks and the yield prediction through trading simulation.

• Journal of Korean Society of Forest Science
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• v.75 no.1
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• pp.1-18
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• 1986

This study was initiated to estimate productivity of Quercus variabilis stand. However the practical objective of this study was to provide some information to establish the basis of selecting the suitable site for Quercus variabilis. The productivity measured in terms of DBH, height, basal area and stem volume was hypothesized, respectively, to be a function of a group of factors. This study considered 32 factors, 20 of which were related to the forest environmental factors such as tree age, latitude, percent slope, etc. and the rest of which were related to soil factors such as soil moisture, total nitrogen, available $P_2O_5$, etc. The data on 4 productivity measurements of Quercus variabilis growth and related factors cited were collected from 99 sample plots in Kyeongbook and chungbook provinces. Some factors considered were, in nature, discrete variables and the others continuous variables. Each kind of factor was classified into 3 or 4 categories and total numbers of such categories were eventually amounted to 110. Then each category was treated as an independent variable. This is amounted to saying that individual variable was treated a dummy variable and assigned a value 1 or 0. However the first category of each factor was deleted from the normal equation for statistical consideration. First of all, each of 4 productivity measurements of Quercus variabilis growth was regressed and, at the same time, those 110 categories. Secondly, the partial correlation coefficients were measured between each pair of 4 productivity measurements and 32 individual foctors. Finally, the relative scores were estimated in order to derive the category ranges. The result of these statistical analyses could be summarized as follows: 1) Growth measurement in terms of height seems to be a more significant criterion for estimation of productivity of Quercus variabilis. 2) Productivity of forest on stocked land may better be estimated in terms of forest environmental factors, on the other hand, that of unstocked land may be estimated in terms of physio-chemical factors of soil. 3) The factors that a strongly positive relation to all growth factors of tree are age group, effective soil, soil moisture, etc. This implies that these factors might effectively be used for criteria for selecting the suitable site for Quercus variabilis. 4) Parent rock, latitude, total nitrogen, age group, effective soil depth, soil moisture, organic matter, etc., had more significant category range for tree growth. Therefore, the suitable site for Quercus variabilis may be selected, based on this information. In conclusion, the above results obtained by the multivariable analysis can be not only the important criteria for estimating the growth of Quercus variabilis but also the useful guidance for selecting the suitable sites and performing the rational of Quercus variabilis forest.

• Journal of the Korean Society of School Health
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• v.2 no.1
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• pp.58-90
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• 1989

This study was attempted to contribute to the development of school health by providing the basic data about the distribution basis and distribution aspect of teachers holding additional school health that are in charge of school health business in parimary schools, middle schools and high schools without any nurse-teacher. This study analyzed literatures about the history, related laws, organization and professional manpower of school health. The emphasis was set on the distribution basis of theachers holding additional school health. The results of this study are as following: 1. The school health of the world dates to the late 18th century in Europe where was free supplying with food for poor children. The school health of Korea orginated from smallpox vaccination which was executed with appearance of modern schools in the late 19th century. 2. The related laws of school health began as a part of Education Law with was constituted in 1949. By the School Health Law constituted in 1967 and the enforcement ordinance of School Health made firm the legal basis of school health. 3. The administrative organs of school health are the Ministry of Education in center and each Board of Education in cities and provinces. For the first time in 1979, the department of school health was established in the organization of the Ministry of Education. And at about the same time of establishment of the department of school health, health section was established in the department of social physical-training in locality. 4. In the manpower of school health which was presented in the related statute of school health, there are the ward chief of education, the superintendent of educational affair, of cities and districts, the mayors, the governors of provinces, the school managers, the principals, the school doctors, the school pharmacists, and the nurse-teachers, including teachers holding additional school health as the practical manpower of school health. 5. In order to get some information on distribution aspect of teachers additional school health, this study made up a questionnaire from August 3 to August 11, 1988. The subjects of this study were 212 leachers who took part in the yearly training for teachers holding additional school health from Kyunggi province, Chungbuk province and Jeonbuk province. The results of the questionnaire are as following: 1. The distribution percentages of teachers holding additional school health according to each Board of Education wich schools are subject to, are as following:70.1% (Kyunggi), 76.5% (Chungbuk), and 81.4% (Jeonbuk). There was a significant difference. The distribution percentages of teachers holding additional school health according to the school levels of 3 provinces are as following: 74.1% (Primary schools), 77.8% (Middle schools), 76.7% (High schools). There were little significant differences. 2. The distribution according to the general characteristics of the subject schools: There were 64.2 percent of primary schools and 35.8 percent of middle schools among 212 schools. 91. 5 percent of schools were located in districts. Public schools formed 55.7% and then national schools were higher in percentage than private schools. 58.5 percent of schools had 1-9 classes, 64.6 percent of schools had 101-500 students, and 90 percents of schools had 1-20 teachers. In considering student sex, the coed school showed the high distribution percentage (Primary schools : 100%, Middle schools: 81.6%). 3. The distribution according to the characteristics of teachers holding additional school health: 93.3 percent of teachers were female, and more than 60 percent of teachers were 20-29 years old. As the age got higher, the percentage became lower. There were little significant differences by marital status. In considering their educational status, 86.8 percent of teachers in primary schools were from teacher's colleges, and 64.5 percent of teachers in middle schools were from education colleges. In considering teaching career, 46.7 percent of teachers had teaching career of less than 2 years. 73.6 percent of teachers had held additional school health for less than one year. More than 80 percent of teachers had participated in the training one time or twice. More than 70 percent of teachers had 1-2 additional jobs except for the school health business. The motivation to hold additional school health is most caused by mandatory order, which accounts for more than 80.0 percent. In considering interesting degree concerning school health, lukewarm answer is the highest of 62.7 percent, followed by affirmative answer of 23.6 percent. In considering their contentment degree respecting additional school health job, "discontent or very discontent"is the highest of 47.6 percent. As a descontent reason of additional school health job, overwork is the highest factor of 37.9 percent. Among addiitional school health job, the most difficult affair is nursing service to be 34.0 percent, followed by health education of 31.6 percent. It testify the need of professional. The source of knowledge about school health has been acquired from masscommunication or private health experience, which account for as much as 56.1 percent. It shows seriousness of lack of professionalism. With regard to neccessity of school health experts, 95.8 percent represents absolute need. With above consideration of study results, I propose as follows : 1. I propose that the authorities concerned unify and improve statute respecting current school health which has not been steadfastly supporting school health business by ambiguity of expression and dualization. 2. I propose that the authorities concerned give the school manager, school staffs and parents of students educational chance with which they can acknowledge the importance of school health and in which they can participate as well as set up alternative policy plan to be albe to vitalize school health committee. 3. I propose that administrative organization practicable to taking totally charge of school health business is established within the Ministry of Education. 4. I propose that the authorities concerned back up and cooperate in an attempt by make school health better and desirable toward development by way of appointing qualitied health teachers on the basis of legally regular teacher staffs.

• Korean Journal of Agricultural Science
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• v.12 no.2
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• pp.356-369
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• 1985

In Korea, inevitable researches for the blast control exactly started from 1927 by the organization of Office of Rural Development with the local extensive outbreak of panicle blast at Jeonlla Buk-Do Province in 1926. At present, the rice blast is still one of the most destructive and widespread diseases in spite of considerable contributions by rice scientists, particularly plant pathologists during last 55 years in Korea. Rice blast control and management are very difficult because of the marked variability in pathogenicity of the blast fungus. From the results obtained through the disease surveys during last 70 years, different 3 prevalence type of blast such as bimodal leaf-blast type, bimodal panicle-blast type and bimodal continual blast type were recognized. In generally speaking, pattern of blast outbreak is said to be characterized by severe outbreak of panicle blast after slight outbreak of leaf blast with discontinuity between leaf and panicle blast. So we have to pay much attention for successful management of panicle blast giving direct influence to rice yield. Main factors induce blast epidemic were pointed out to be breakdown of the disease resistance, nutritional unbalance such as excess application of nitrogen, delay of transplantation and longspell of rain fall by extensive surveys and researches on blast during last 70 years in Korea. The fact some of Japonica varieties such as Kokuryomiyako, Tamanishiki, Ginbozu and Pungok belong to varietal group A had been cultivated with extensive acrage over 30 years in this country should be mentioned by Korean rice scientists. Differences in field resistance between varieties in the same group are detectable and apparently small but sometimes epidemiologically significant differential effects may be found out in case of blast. Much more attention should be payed to accumulate the knowledges on field resistance for successful management of blast. Excess application of nitrogen is more effective to outbreak of panicle blast than that of leaf blast of IR varieties. In comparatively low level application of nitrogen infection rate of panicle blast of IR varieties is considerably high. Low temperature effects on outbreak of blast is very great. It results in remarkable increase of the inoculum potential on the leaf lesions and infection of panicle blast in leaf sheathes of IR varieties during the booting stage. In economic point of view, it is concluded that 5 times sprays of effective fungicides including 3 times before and 2 times after heading is good enough to control blast. We have experienced no one of control measures for blast is superior to all others. The integrated control measures was established as guideline of blast control around 1950 in Korea. This guideline must be helpful for rice growers as long as rice growing continue.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.2
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• pp.101-108
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• 2017

Purpose: The proton used in proton therapy has a characteristic of giving a small dose to the normal tissue in front of the tumor site while forming a Bragg peak at the cancer tissue site and giving up the maximum dose and disappearing immediately. It is very important to verify the proton arrival position. In this study, we used the off-line PET CT method to measure the distribution of positron emitted from nucleons such as 11C (half-life = 20 min), 150 (half-life = 2 min) and 13N The range and distal falloff point of the proton were verified by measurement. Materials and Methods: In the IEC 2001 Body Phantom, 37 mm, 28 mm, and 22 mm spheres were inserted. The phantom was filled with water to obtain a CT image for each sphere size. To verify the proton range and distal falloff points, As a treatment planning system, SOBP were set at 46 mm on 37 mm sphere, 37 mm on 28 mm, and 33 mm on 22 mm sphere for each sphere size. The proton was scanned in the same center with a single beam of Gantry 0 degree by the scanning method. The phantom was scanned using PET-CT equipment. In the PET-CT image acquisition method, 50 images were acquired per minute, four ROIs including the spheres in the phantom were set, and 10 images were reconstructed. The activity profile according to the depth was compared to the dose profile according to the sphere size established in the treatment plan Results: The PET-CT activity profile decreased rapidly at the distal falloff position in the 37 mm, 28 mm, and 22 mm spheres as well as the dose profile. However, in the SOBP section, which is a range for evaluating the range, the results in the proximal part of the activity profile are different from those of the dose profile, and the distal falloff position is compared with the proton therapy plan and PET-CT As a result, the maximum difference of 1.4 mm at the 50 % point of the Max dose, 1.1 mm at the 45 % point at the 28 mm sphere, and the difference at the 22 mm sphere at the maximum point of 1.2 mm were all less than 1.5 mm in the 37 mm sphere. Conclusion: To maximize the advantages of proton therapy, it is very important to verify the range of the proton beam. In this study, the proton range was confirmed by the SOBP and the distal falloff position of the proton beam using PET-CT. As a result, the difference of the distally falloff position between the activity distribution measured by PET-CT and the proton therapy plan was 1.4 mm, respectively. This may be used as a reference for the dose margin applied in the proton therapy plan.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.1
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• pp.61-67
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• 1977

A study was conducted in order to compare the topdressing method of the conventional fertilizers as control and the deep application method of the ball complex fertilizer newly developed. The ball complex fertilizer consisted of 5% of nitrogen, 5% of phosphorus, and 7% of potassium. Basal application of nitrogen for the rice plant was the same for both control plots and ball complex plots. One ball complex fertilizer per four hills was applied at depth of 12~13cm 35days before heading stage while control plot received three times topdressing at different growth stages as usual practice. The results obtained were as follows. 1. The ball complex fertilizer applied in the soil was continuously utilized by the rice plants until harvest time while nitrogen and potassium uptake of control plots was reduced rapidly after heading stage. Daily uptake of nitrogen and potassium per hill at maturing stage were 0.45mg and 0.68mg in control plots, but 4.80mg and 7.0mg respectively in ball complex plots. 2. Dry matter productivity of the rice plant in control plots, well coinciding with nutrients uptake pattern, was maximum just after heading stage decreased at maturing stage. But dry matter productivity in ball complex plots was much higher at maturing stage than at heading stage. 3. Ball complex application increased effective tillering rate, causing higher panicle number per hill. 4. Ball complex application brought about 528kg/10a of hulled grain yield while the conventional practice 423kg/10a. 5. Deep application of ball complex was superior to usual practice in terms of yield components such as panicle number per hill, filled grain number per panicle, maturing rate, and 1,000 grain weight. 6. From the morphological characteristics point of view, the deep application of ball complex made the flag leaf and the 2nd leaf heavier, larger and broader as compared to control treatment. 7. It is considered that by applying the ball complex fertilizer at depth of 12~13cm sufficient amount of nitrogen and potassium could be utilized by rice plants during the maturing stage and assimilated in the leaf blade, consequently making the flag leaf and the 2nd leaf bigger and healthier. The fact can easily explain that the ball complex plots had higher capacity of photosynthesis, less discoloration of lower leaves, bigger leaf area index, and better grain yield as compared to the conventional practice. In conclusion the deep application method of the ball complex fertilizer was superior to the routine topdressing method of the usual fertilizers.

• The Korean Journal of Air & Space Law and Policy
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• v.30 no.1
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• pp.31-64
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• 2015

The Chicago Convention and Annexes have become the basis of aviation safety regulations for every contracting state. Generally, aviation safety regulations refer to the SARPs provided in the Annexes of the Chicago Convention. In order to properly reflect international aviation safety regulations, constant studies of the aviation fields are of paramount importance. Treaties duly concluded and promulgated under the Constitution and the generally recognized rules of international law shall have the same effect as the domestic laws of the Republic of Korea. Each contracting state to the Chicago Convention should meet ICAO SARPs about AOC and FAOC. According to ICAO SARPs, Civil Aviation Authorities shall issue AOC to air carriers of the state, but don't require to issue for foreign air carrier. However some contracting states of the Chicago Convention issue FAOC and/or Operations Specifications for the foreign operators. This FAOC is being expanded from USA to the other contracting states. Foreign operators have doubly burden to implement AOC of the ICAO SARPs because FAOC is an additional requirement other than that prescribed by the ICAO SARPs In Article 33, the Chicago Convention stipulates that each contracting state shall recognize the validity of the certificates of airworthiness and licenses issued by other contracting states as long as they are equal to or above the minimum standards of the ICAO. In ICAO Annex 6, each contracting state shall recognize as valid an air operator certificate issued by another contracting state, provided that the requirements under which the certificate was issued are at least equal to the applicable Standards specified in this Annex. States shall establish a programme with procedures for the surveillance of operations in their territory by a foreign operator and for taking appropriate action when necessary to preserve safety. Consequently, it is submitted that the unilateral action of the states issuing the FAOC to the foreign air carriers of other states is against the Convention. Hence, I make some proposals on the FAOC as an example of comprehensive problem solving after comparative study with ICAO SARPs and the contracting state's regulations. Some issues must be improved and I have made amendment proposals to meet ICAO SARPs and to strengthen aviation development. Operators should be approved by FAOC at most 190 if all states require FAOC. Hence, it is highly recommended to eliminate the FAOC or reduce the restrictions it imposes. In certain compliance-related issues, delayed process shall not be permitted to flight operations. In addition, it is necessary for the ICAO to provide more unified and standardized guidelines in order to avoid confusion or bias regarding the arbitrary expansion of the FAOC. For all the issue mentioned above, I have studied the ICAO SARPs and some state's regulation regarding FAOC, and suggested some proposals on the FAOC as an example of comprehensive problem solving. I hope that this paper is 1) to help understanding about the international issue, 2) to help the improvement of korean aviation regulations, 3) to help compliance with international standards and to contribute to the promotion of aviation safety, in addition.

• Journal of Intelligence and Information Systems
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• v.23 no.1
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• pp.47-67
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• 2017

Steel plate faults is one of important factors to affect the quality and price of the steel plates. So far many steelmakers generally have used visual inspection method that could be based on an inspector's intuition or experience. Specifically, the inspector checks the steel plate faults by looking the surface of the steel plates. However, the accuracy of this method is critically low that it can cause errors above 30% in judgment. Therefore, accurate steel plate faults diagnosis system has been continuously required in the industry. In order to meet the needs, this study proposed a new steel plate faults diagnosis system using Simultaneous MTS (S-MTS), which is an advanced Mahalanobis Taguchi System (MTS) algorithm, to classify various surface defects of the steel plates. MTS has generally been used to solve binary classification problems in various fields, but MTS was not used for multiclass classification due to its low accuracy. The reason is that only one mahalanobis space is established in the MTS. In contrast, S-MTS is suitable for multi-class classification. That is, S-MTS establishes individual mahalanobis space for each class. 'Simultaneous' implies comparing mahalanobis distances at the same time. The proposed steel plate faults diagnosis system was developed in four main stages. In the first stage, after various reference groups and related variables are defined, data of the steel plate faults is collected and used to establish the individual mahalanobis space per the reference groups and construct the full measurement scale. In the second stage, the mahalanobis distances of test groups is calculated based on the established mahalanobis spaces of the reference groups. Then, appropriateness of the spaces is verified by examining the separability of the mahalanobis diatances. In the third stage, orthogonal arrays and Signal-to-Noise (SN) ratio of dynamic type are applied for variable optimization. Also, Overall SN ratio gain is derived from the SN ratio and SN ratio gain. If the derived overall SN ratio gain is negative, it means that the variable should be removed. However, the variable with the positive gain may be considered as worth keeping. Finally, in the fourth stage, the measurement scale that is composed of selected useful variables is reconstructed. Next, an experimental test should be implemented to verify the ability of multi-class classification and thus the accuracy of the classification is acquired. If the accuracy is acceptable, this diagnosis system can be used for future applications. Also, this study compared the accuracy of the proposed steel plate faults diagnosis system with that of other popular classification algorithms including Decision Tree, Multi Perception Neural Network (MLPNN), Logistic Regression (LR), Support Vector Machine (SVM), Tree Bagger Random Forest, Grid Search (GS), Genetic Algorithm (GA) and Particle Swarm Optimization (PSO). The steel plates faults dataset used in the study is taken from the University of California at Irvine (UCI) machine learning repository. As a result, the proposed steel plate faults diagnosis system based on S-MTS shows 90.79% of classification accuracy. The accuracy of the proposed diagnosis system is 6-27% higher than MLPNN, LR, GS, GA and PSO. Based on the fact that the accuracy of commercial systems is only about 75-80%, it means that the proposed system has enough classification performance to be applied in the industry. In addition, the proposed system can reduce the number of measurement sensors that are installed in the fields because of variable optimization process. These results show that the proposed system not only can have a good ability on the steel plate faults diagnosis but also reduce operation and maintenance cost. For our future work, it will be applied in the fields to validate actual effectiveness of the proposed system and plan to improve the accuracy based on the results.

• Journal of Intelligence and Information Systems
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• v.23 no.1
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• pp.1-22
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• 2017

Analysis of future business or investment opportunities, such as business feasibility analysis and company or technology valuation, necessitate objective estimation on the relevant market and expected sales. While there are various ways to classify the estimation methods of these new sales or market size, they can be broadly divided into top-down and bottom-up approaches by benchmark references. Both methods, however, require a lot of resources and time. Therefore, we propose a data-based intelligent demand forecasting system to support evaluation of new business. This study focuses on analogical forecasting, one of the traditional quantitative forecasting methods, to develop sales forecasting intelligence systems for new businesses. Instead of simply estimating sales for a few years, we hereby propose a method of estimating the sales of new businesses by using the initial sales and the sales growth rate of similar companies. To demonstrate the appropriateness of this method, it is examined whether the sales performance of recently established companies in the same industry category in Korea can be utilized as a reference variable for the analogical forecasting. In this study, we examined whether the phenomenon of "mean reversion" was observed in the sales of start-up companies in order to identify errors in estimating sales of new businesses based on industry sales growth rate and whether the differences in business environment resulting from the different timing of business launch affects growth rate. We also conducted analyses of variance (ANOVA) and latent growth model (LGM) to identify differences in sales growth rates by industry category. Based on the results, we proposed industry-specific range and linear forecasting models. This study analyzed the sales of only 150,000 start-up companies in Korea in the last 10 years, and identified that the average growth rate of start-ups in Korea is higher than the industry average in the first few years, but it shortly shows the phenomenon of mean-reversion. In addition, although the start-up founding juncture affects the sales growth rate, it is not high significantly and the sales growth rate can be different according to the industry classification. Utilizing both this phenomenon and the performance of start-up companies in relevant industries, we have proposed two models of new business sales based on the sales growth rate. The method proposed in this study makes it possible to objectively and quickly estimate the sales of new business by industry, and it is expected to provide reference information to judge whether sales estimated by other methods (top-down/bottom-up approach) pass the bounds from ordinary cases in relevant industry. In particular, the results of this study can be practically used as useful reference information for business feasibility analysis or technical valuation for entering new business. When using the existing top-down method, it can be used to set the range of market size or market share. As well, when using the bottom-up method, the estimation period may be set in accordance of the mean reverting period information for the growth rate. The two models proposed in this study will enable rapid and objective sales estimation of new businesses, and are expected to improve the efficiency of business feasibility analysis and technology valuation process by developing intelligent information system. In academic perspectives, it is a very important discovery that the phenomenon of 'mean reversion' is found among start-up companies out of general small-and-medium enterprises (SMEs) as well as stable companies such as listed companies. In particular, there exists the significance of this study in that over the large-scale data the mean reverting phenomenon of the start-up firms' sales growth rate is different from that of the listed companies, and that there is a difference in each industry. If a linear model, which is useful for estimating the sales of a specific company, is highly likely to be utilized in practical aspects, it can be explained that the range model, which can be used for the estimation method of the sales of the unspecified firms, is highly likely to be used in political aspects. It implies that when analyzing the business activities and performance of a specific industry group or enterprise group there is political usability in that the range model enables to provide references and compare them by data based start-up sales forecasting system.