• Title/Summary/Keyword: 효과적

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Changes of Polyamine Metabolism and Delayed Neuronal Degeneration of Hippocampus after Transient Cerebral Ischemia in Mongolian Gerbils (뇌허혈 손상에 있어서 Polyamine 대사의 변동이 해마신경세포의 지연성괴사에 미치는 효과에 관한 연구)

  • Shin, Kyung-Ho;Shin, Hwa-Jung;Lee, Young-Jae;Kim, Hyung-Gun;Choi, Sang-Hyun;Chun, Yeon-Sook;Chun, Boe-Gwun
    • The Korean Journal of Pharmacology
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    • v.32 no.3
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    • pp.323-334
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    • 1996
  • Male Mongolian gerbils $(60{\sim}80g)$ were given DL-difluoromethylornithine (DFMO; 250mg/kg, ip) and methylglyoxal bis(guanylhydrazone) (MGBG; 50 mg/k, ip), respectively, 1 h prior to transient (7 min) occlusion of bilateral common carotid arteries (OBC7) and a daily dose of one of them for 6 days after recirculation, and the polyamine contents, activities of ornithine and S-adenosylmethionine decarboxylases (ODC and SAM-DC), and light microscopic findings of the hippocampus were evaluated. The hippocampal putrescine (PT) levels of the control gerbils treated with saline (STGr), markedly increased after OBC7, showing a peak level at 24 h after recirculation. The peak PT level was reduced in DFMO treated gerbils (DTCr) and in MGBG treated gerbils (MTGr). And 7 days after recirculation, the PT level of DTGr was decreased to about 75% of the PT level in the sham operated group (nonTGr) and to about 55% of the STGr level, respectively. The hippocampal spermidine (SD) level of STGr tended to decline, showing the lowest value at 8 h after recirculation. But the spermidine (SD) level of DTGr was somewhat higher at 8 h after OBC7 than those of STGr and MTGr The hippocampal spermine (SM) levels of all the experimental groups were little changed for 7 days after OBC. OBC7 markedly increased the hippocampal ODC activity. reaching a maximum (about 3 times higher than preischemic level) at 8 h and rapidly recovered to the control value by 24 h in STGr gerbils, and the OBC7-induced increase of ODC activity was significantly attenuated by DFMO or MGBG treatment. Whereas OBC7 induced a rapid decrease of the hippocampal SAMDC activity follwed by gradual recovery to the preischemic level, and the decrease of the SAMDC activity was slightly attenuated by DFMO or MGBG treatment. 7 Days after OBC7 the histological finding of the hippocampal complex stained with cresyl violet showed an extensive delayed neuronal damage in the CA1 region and to a lesser extent, in the dentate gyrus, sparing the CA3 region. And the neuronal death was aggevated by DFMO but significantly attenuated by MGBG. The immunochemical reactivity of hippocampus to anti-GFAP antibody was significantly increased in the CA1 region and to a lesser extent, in the dentate gyrus 7 days after OBC7, but was little changed in the CA3. And the increase of the anti-GFAP immunoreactivity was moderately enhanced by DFMO and significantly suppressed by MGBG. These results suggest that the polyamine metabolism may play a modulatory role in the ischemic brain damage.

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The Causes of Conflict and the Effect of Control Mechanisms on Conflict Resolution between Manufacturer and Supplier (제조-공급자간 갈등 원인과 거래조정 방식의 갈등관리 효과)

  • Rhee, Jin Hwa
    • Journal of Distribution Research
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    • v.17 no.4
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    • pp.55-80
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    • 2012
  • I. Introduction Developing the relationships between companies is very important issue to ensure a competitive advantage in today's business environment (Bleeke & Ernst 1991; Mohr & Spekman 1994; Powell 1990). Partnerships between companies are based on having same goals, pursuing mutual understanding, and having a professional level of interdependence. By having such a partnerships and cooperative efforts between companies, they will achieve efficiency and effectiveness of their business (Mohr and Spekman, 1994). However, it is difficult to expect these ideal results only in the B2B corporate transaction. According to agency theory which is the well-accepted theory in various fields of business strategy, organization, and marketing, the two independent companies have fundamentally different corporate purposes. Also there is a higher chance of developing opportunism and conflict due to natures of human(organization), such as self-interest, bounded rationality, risk aversion, and environment factor as imbalance of information (Eisenhardt 1989). That is, especially partnerships between principal(or buyer) and agent(or supplier) of companies within supply chain, the business contract itself will not provide competitive advantage. But managing partnership between companies is the key to success. Therefore, managing partnership between manufacturer and supplier, and finding causes of conflict are essential to improve B2B performance. In conclusion, based on prior researches and Agency theory, this study will clarify how business hazards cause conflicts on supply chain and then identify how developed conflicts have been managed by two control mechanisms. II. Research model III. Method In order to validate our research model, this study gathered questionnaires from small and medium sized enterprises(SMEs). In Korea, SMEs mean the firms whose employee is under 300 and capital is under 8 billion won(about 7.2 million dollar). We asked the manufacturer's perception about the relationship with the biggest supplier, and our key informants are denied to a person responsible for buying(ex)CEO, executives, managers of purchasing department, and so on). In detail, we contact by telephone to our initial sample(about 1,200 firms) and introduce our research motivation and send our questionnaires by e-mail, mail, and direct survey. Finally we received 361 data and eliminate 32 inappropriate questionnaires. We use 329 manufactures' data on analysis. The purpose of this study is to identify the anticipant role of business hazard (environmental dynamism, asset specificity) and investigate the moderating effect of control mechanism(formal control, social control) on conflict-performance relationship. To find out moderating effect of control methods, we need to compare the regression weight between low versus. high group(about level of exercised control methods). Therefore we choose the structural equation modeling method that is proper to do multi-group analysis. The data analysis is performed by AMOS 17.0 software, and model fits are good statically (CMIN/DF=1.982, p<.000, CFI=.936, IFI=.937, RMSEA=.056). IV. Result V. Discussion Results show that the higher environmental dynamism and asset specificity(on particular supplier) buyer(manufacturer) has, the more B2B conflict exists. And this conflict affect relationship quality and financial outcomes negatively. In addition, social control and formal control could weaken the negative effect of conflict on relationship quality significantly. However, unlikely to assure conflict resolution effect of control mechanisms on relationship quality, financial outcomes are changed by neither social control nor formal control. We could explain this results with the characteristics of our sample, SMEs(Small and Medium sized Enterprises). Financial outcomes of these SMEs(manufacturer or principal) are affected by their customer(usually major company) more easily than their supplier(or agent). And, in recent few years, most of companies have suffered from financial problems because of global economic recession. It means that it is hard to evaluate the contribution of supplier(agent). Therefore we also support the suggestion of Gladstein(1984), Poppo & Zenger(2002) that relational performance variable can capture the focal outcomes of relationship(exchange) better than financial performance variable. This study has some implications that it tests the sources of conflict and investigates the effect of resolution methods of B2B conflict empirically. And, especially, it finds out the significant moderating effect of formal control which past B2B management studies have ignored in Korea.

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PROPAGATION OF THE BLUE CRAB, PORTUNUS TRITUBERCULATUS (MIERS) (꽃게 Portunus trituberculatus (MIERS)의 종묘 생산에 관한 연구)

  • PYEN Choong-Kyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.3 no.3
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    • pp.187-198
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    • 1970
  • The author succeeded in rearing the young blue crab from the first stage of zoe ato the true crab shape, and during this time he observed their growth and metamorphosis. The relationships between the number of eggs carried by female crabs (E) and the carapace width (C) and body weight (W) are shown as follows: E= 27.9049C-281.8155, E=0.5682 W-116.4606. There are five zoeal stages and a megalopa in the complete larval development of the blue crab. Water temperature in rearing aquaria ranged from 21.4 to $25.2^{\circ}C$. The duration of each zoeal stage was two days on the average. After the fifth moulting, the zoea becomes megalopa and 5 to 6 days later the megalopa moults and develops into the first stage of adult crab shape. The carapace width of megalopa measured about 1.70 mm and the carapace length, from the tip of the rostrum to the posterior dorsal margin of the carapace, was about 2.78 mm on the average. The carapace width and length of the first crab, 18 days after hatching, measured about 4.48 mm and 2.62 mm respectively. After two days, the first crab moulted and grew into the second crab with about 6.47 mm in carapace width and 4.66 mm in carapace length. The larval rearing in the outdoor tank shelved better results than in the indoor aquarium. The highest mortality occurred when the first stage of zoea moulted into the second stage. Percentage of crabs which survived, from the first crab to the ninth crab stages, was about $55\%$. The relationships between rearing days (D) and the carapace width (C), carapace length (L) and body weight (W) of the crab stages during 40 days of rearing are shown as follows. Carapace width, Indoor: C=1.1250D+1.7227 Outdoor C=1.3465D -0.2449 Carapace length, Indoor: L=0.6654D+1.6712 Outdoor: L=0.7893D+0.6919 Body Weight, Outdoor: $$W=1.15e^{0.12423D}$$ Indoor: $$W=6.759\times10^{-2}D^{1.2598}$$ (9-19 day old crabs) Outdoor: $$W=4.136\times10^{-2}D^{1.6024}$$ (21-40 day old crabs) During the crab stage, the following relationships between the number of moulting times and the carapace width (C), carapace length (L) and body weight (W) were found as follows: $$C=5.2e^{0.28119N}$$ $$L=3.65e^{0.26372N}$$ $$W= 0.14e^{0.7037N}$$ The relationships between the carapace length (L) and the carapace width (C) and body weight (W) of the crab stages are shown as follows: Carapace length, mm Formula 2.62-27.17 L=1.6864C-1.0387 7.47-18.53 $$W=9.367\times10^{-5}C^{3.5567}$$ 22.11-27.17 $$W=3.406\times10^{-5}C{3.8571}$$

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A Study of Factors Associated with Software Developers Job Turnover (데이터마이닝을 활용한 소프트웨어 개발인력의 업무 지속수행의도 결정요인 분석)

  • Jeon, In-Ho;Park, Sun W.;Park, Yoon-Joo
    • Journal of Intelligence and Information Systems
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    • v.21 no.2
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    • pp.191-204
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    • 2015
  • According to the '2013 Performance Assessment Report on the Financial Program' from the National Assembly Budget Office, the unfilled recruitment ratio of Software(SW) Developers in South Korea was 25% in the 2012 fiscal year. Moreover, the unfilled recruitment ratio of highly-qualified SW developers reaches almost 80%. This phenomenon is intensified in small and medium enterprises consisting of less than 300 employees. Young job-seekers in South Korea are increasingly avoiding becoming a SW developer and even the current SW developers want to change careers, which hinders the national development of IT industries. The Korean government has recently realized the problem and implemented policies to foster young SW developers. Due to this effort, it has become easier to find young SW developers at the beginning-level. However, it is still hard to recruit highly-qualified SW developers for many IT companies. This is because in order to become a SW developing expert, having a long term experiences are important. Thus, improving job continuity intentions of current SW developers is more important than fostering new SW developers. Therefore, this study surveyed the job continuity intentions of SW developers and analyzed the factors associated with them. As a method, we carried out a survey from September 2014 to October 2014, which was targeted on 130 SW developers who were working in IT industries in South Korea. We gathered the demographic information and characteristics of the respondents, work environments of a SW industry, and social positions for SW developers. Afterward, a regression analysis and a decision tree method were performed to analyze the data. These two methods are widely used data mining techniques, which have explanation ability and are mutually complementary. We first performed a linear regression method to find the important factors assaociated with a job continuity intension of SW developers. The result showed that an 'expected age' to work as a SW developer were the most significant factor associated with the job continuity intention. We supposed that the major cause of this phenomenon is the structural problem of IT industries in South Korea, which requires SW developers to change the work field from developing area to management as they are promoted. Also, a 'motivation' to become a SW developer and a 'personality (introverted tendency)' of a SW developer are highly importantly factors associated with the job continuity intention. Next, the decision tree method was performed to extract the characteristics of highly motivated developers and the low motivated ones. We used well-known C4.5 algorithm for decision tree analysis. The results showed that 'motivation', 'personality', and 'expected age' were also important factors influencing the job continuity intentions, which was similar to the results of the regression analysis. In addition to that, the 'ability to learn' new technology was a crucial factor for the decision rules of job continuity. In other words, a person with high ability to learn new technology tends to work as a SW developer for a longer period of time. The decision rule also showed that a 'social position' of SW developers and a 'prospect' of SW industry were minor factors influencing job continuity intensions. On the other hand, 'type of an employment (regular position/ non-regular position)' and 'type of company (ordering company/ service providing company)' did not affect the job continuity intension in both methods. In this research, we demonstrated the job continuity intentions of SW developers, who were actually working at IT companies in South Korea, and we analyzed the factors associated with them. These results can be used for human resource management in many IT companies when recruiting or fostering highly-qualified SW experts. It can also help to build SW developer fostering policy and to solve the problem of unfilled recruitment of SW Developers in South Korea.

Methods for Integration of Documents using Hierarchical Structure based on the Formal Concept Analysis (FCA 기반 계층적 구조를 이용한 문서 통합 기법)

  • Kim, Tae-Hwan;Jeon, Ho-Cheol;Choi, Joong-Min
    • Journal of Intelligence and Information Systems
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    • v.17 no.3
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    • pp.63-77
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    • 2011
  • The World Wide Web is a very large distributed digital information space. From its origins in 1991, the web has grown to encompass diverse information resources as personal home pasges, online digital libraries and virtual museums. Some estimates suggest that the web currently includes over 500 billion pages in the deep web. The ability to search and retrieve information from the web efficiently and effectively is an enabling technology for realizing its full potential. With powerful workstations and parallel processing technology, efficiency is not a bottleneck. In fact, some existing search tools sift through gigabyte.syze precompiled web indexes in a fraction of a second. But retrieval effectiveness is a different matter. Current search tools retrieve too many documents, of which only a small fraction are relevant to the user query. Furthermore, the most relevant documents do not nessarily appear at the top of the query output order. Also, current search tools can not retrieve the documents related with retrieved document from gigantic amount of documents. The most important problem for lots of current searching systems is to increase the quality of search. It means to provide related documents or decrease the number of unrelated documents as low as possible in the results of search. For this problem, CiteSeer proposed the ACI (Autonomous Citation Indexing) of the articles on the World Wide Web. A "citation index" indexes the links between articles that researchers make when they cite other articles. Citation indexes are very useful for a number of purposes, including literature search and analysis of the academic literature. For details of this work, references contained in academic articles are used to give credit to previous work in the literature and provide a link between the "citing" and "cited" articles. A citation index indexes the citations that an article makes, linking the articleswith the cited works. Citation indexes were originally designed mainly for information retrieval. The citation links allow navigating the literature in unique ways. Papers can be located independent of language, and words in thetitle, keywords or document. A citation index allows navigation backward in time (the list of cited articles) and forwardin time (which subsequent articles cite the current article?) But CiteSeer can not indexes the links between articles that researchers doesn't make. Because it indexes the links between articles that only researchers make when they cite other articles. Also, CiteSeer is not easy to scalability. Because CiteSeer can not indexes the links between articles that researchers doesn't make. All these problems make us orient for designing more effective search system. This paper shows a method that extracts subject and predicate per each sentence in documents. A document will be changed into the tabular form that extracted predicate checked value of possible subject and object. We make a hierarchical graph of a document using the table and then integrate graphs of documents. The graph of entire documents calculates the area of document as compared with integrated documents. We mark relation among the documents as compared with the area of documents. Also it proposes a method for structural integration of documents that retrieves documents from the graph. It makes that the user can find information easier. We compared the performance of the proposed approaches with lucene search engine using the formulas for ranking. As a result, the F.measure is about 60% and it is better as about 15%.

The way to make training data for deep learning model to recognize keywords in product catalog image at E-commerce (온라인 쇼핑몰에서 상품 설명 이미지 내의 키워드 인식을 위한 딥러닝 훈련 데이터 자동 생성 방안)

  • Kim, Kitae;Oh, Wonseok;Lim, Geunwon;Cha, Eunwoo;Shin, Minyoung;Kim, Jongwoo
    • Journal of Intelligence and Information Systems
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    • v.24 no.1
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    • pp.1-23
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    • 2018
  • From the 21st century, various high-quality services have come up with the growth of the internet or 'Information and Communication Technologies'. Especially, the scale of E-commerce industry in which Amazon and E-bay are standing out is exploding in a large way. As E-commerce grows, Customers could get what they want to buy easily while comparing various products because more products have been registered at online shopping malls. However, a problem has arisen with the growth of E-commerce. As too many products have been registered, it has become difficult for customers to search what they really need in the flood of products. When customers search for desired products with a generalized keyword, too many products have come out as a result. On the contrary, few products have been searched if customers type in details of products because concrete product-attributes have been registered rarely. In this situation, recognizing texts in images automatically with a machine can be a solution. Because bulk of product details are written in catalogs as image format, most of product information are not searched with text inputs in the current text-based searching system. It means if information in images can be converted to text format, customers can search products with product-details, which make them shop more conveniently. There are various existing OCR(Optical Character Recognition) programs which can recognize texts in images. But existing OCR programs are hard to be applied to catalog because they have problems in recognizing texts in certain circumstances, like texts are not big enough or fonts are not consistent. Therefore, this research suggests the way to recognize keywords in catalog with the Deep Learning algorithm which is state of the art in image-recognition area from 2010s. Single Shot Multibox Detector(SSD), which is a credited model for object-detection performance, can be used with structures re-designed to take into account the difference of text from object. But there is an issue that SSD model needs a lot of labeled-train data to be trained, because of the characteristic of deep learning algorithms, that it should be trained by supervised-learning. To collect data, we can try labelling location and classification information to texts in catalog manually. But if data are collected manually, many problems would come up. Some keywords would be missed because human can make mistakes while labelling train data. And it becomes too time-consuming to collect train data considering the scale of data needed or costly if a lot of workers are hired to shorten the time. Furthermore, if some specific keywords are needed to be trained, searching images that have the words would be difficult, as well. To solve the data issue, this research developed a program which create train data automatically. This program can make images which have various keywords and pictures like catalog and save location-information of keywords at the same time. With this program, not only data can be collected efficiently, but also the performance of SSD model becomes better. The SSD model recorded 81.99% of recognition rate with 20,000 data created by the program. Moreover, this research had an efficiency test of SSD model according to data differences to analyze what feature of data exert influence upon the performance of recognizing texts in images. As a result, it is figured out that the number of labeled keywords, the addition of overlapped keyword label, the existence of keywords that is not labeled, the spaces among keywords and the differences of background images are related to the performance of SSD model. This test can lead performance improvement of SSD model or other text-recognizing machine based on deep learning algorithm with high-quality data. SSD model which is re-designed to recognize texts in images and the program developed for creating train data are expected to contribute to improvement of searching system in E-commerce. Suppliers can put less time to register keywords for products and customers can search products with product-details which is written on the catalog.

Business Application of Convolutional Neural Networks for Apparel Classification Using Runway Image (합성곱 신경망의 비지니스 응용: 런웨이 이미지를 사용한 의류 분류를 중심으로)

  • Seo, Yian;Shin, Kyung-shik
    • Journal of Intelligence and Information Systems
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    • v.24 no.3
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    • pp.1-19
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    • 2018
  • Large amount of data is now available for research and business sectors to extract knowledge from it. This data can be in the form of unstructured data such as audio, text, and image data and can be analyzed by deep learning methodology. Deep learning is now widely used for various estimation, classification, and prediction problems. Especially, fashion business adopts deep learning techniques for apparel recognition, apparel search and retrieval engine, and automatic product recommendation. The core model of these applications is the image classification using Convolutional Neural Networks (CNN). CNN is made up of neurons which learn parameters such as weights while inputs come through and reach outputs. CNN has layer structure which is best suited for image classification as it is comprised of convolutional layer for generating feature maps, pooling layer for reducing the dimensionality of feature maps, and fully-connected layer for classifying the extracted features. However, most of the classification models have been trained using online product image, which is taken under controlled situation such as apparel image itself or professional model wearing apparel. This image may not be an effective way to train the classification model considering the situation when one might want to classify street fashion image or walking image, which is taken in uncontrolled situation and involves people's movement and unexpected pose. Therefore, we propose to train the model with runway apparel image dataset which captures mobility. This will allow the classification model to be trained with far more variable data and enhance the adaptation with diverse query image. To achieve both convergence and generalization of the model, we apply Transfer Learning on our training network. As Transfer Learning in CNN is composed of pre-training and fine-tuning stages, we divide the training step into two. First, we pre-train our architecture with large-scale dataset, ImageNet dataset, which consists of 1.2 million images with 1000 categories including animals, plants, activities, materials, instrumentations, scenes, and foods. We use GoogLeNet for our main architecture as it has achieved great accuracy with efficiency in ImageNet Large Scale Visual Recognition Challenge (ILSVRC). Second, we fine-tune the network with our own runway image dataset. For the runway image dataset, we could not find any previously and publicly made dataset, so we collect the dataset from Google Image Search attaining 2426 images of 32 major fashion brands including Anna Molinari, Balenciaga, Balmain, Brioni, Burberry, Celine, Chanel, Chloe, Christian Dior, Cividini, Dolce and Gabbana, Emilio Pucci, Ermenegildo, Fendi, Giuliana Teso, Gucci, Issey Miyake, Kenzo, Leonard, Louis Vuitton, Marc Jacobs, Marni, Max Mara, Missoni, Moschino, Ralph Lauren, Roberto Cavalli, Sonia Rykiel, Stella McCartney, Valentino, Versace, and Yve Saint Laurent. We perform 10-folded experiments to consider the random generation of training data, and our proposed model has achieved accuracy of 67.2% on final test. Our research suggests several advantages over previous related studies as to our best knowledge, there haven't been any previous studies which trained the network for apparel image classification based on runway image dataset. We suggest the idea of training model with image capturing all the possible postures, which is denoted as mobility, by using our own runway apparel image dataset. Moreover, by applying Transfer Learning and using checkpoint and parameters provided by Tensorflow Slim, we could save time spent on training the classification model as taking 6 minutes per experiment to train the classifier. This model can be used in many business applications where the query image can be runway image, product image, or street fashion image. To be specific, runway query image can be used for mobile application service during fashion week to facilitate brand search, street style query image can be classified during fashion editorial task to classify and label the brand or style, and website query image can be processed by e-commerce multi-complex service providing item information or recommending similar item.

Comparison and evaluation of volumetric modulated arc therapy and intensity modulated radiation therapy plans for postoperative radiation therapy of prostate cancer patient using a rectal balloon (직장풍선을 삽입한 전립선암 환자의 수술 후 방사선 치료 시 용적변조와 세기변조방사선치료계획 비교 평가)

  • Jung, hae youn;Seok, jin yong;Hong, joo wan;Chang, nam jun;Choi, byeong don;Park, jin hong
    • The Journal of Korean Society for Radiation Therapy
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    • v.27 no.1
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    • pp.45-52
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    • 2015
  • Purpose : The dose distribution of organ at risk (OAR) and normal tissue is affected by treatment technique in postoperative radiation therapy for prostate cancer. The aim of this study was to compare dose distribution characteristic and to evaluate treatment efficiency by devising VMAT plans according to applying differed number of arc and IMRT plan for postoperative patient of prostate cancer radiation therapy using a rectal balloon. Materials and Methods : Ten patients who received postoperative prostate radiation therapy in our hospital were compared. CT images of patients who inserted rectal balloon were acquired with 3 mm thickness and 10 MV energy of HD120MLC equipped Truebeam STx (Varian, Palo Alto, USA) was applied by using Eclipse (Version 11.0, Varian, Palo Alto, USA). 1 Arc, 2 Arc VMAT plans and 7-field IMRT plan were devised for each patient and same values were applied for dose volume constraint and plan normalization. To evaluate these plans, PTV coverage, conformity index (CI) and homogeneity index (HI) were compared and $R_{50%}$ was calculated to assess low dose spillage as per treatment plan. $D_{25%}$ of rectum and bladder Dmean were compared on OAR. And to evaluate the treatment efficiency, total monitor units(MU) and delivery time were considered. Each assessed result was analyzed by average value of 10 patients. Additionally, portal dosimetry was carried out for accuracy verification of beam delivery. Results : There was no significant difference on PTV coverage and HI among 3 plans. Especially CI and $R_{50%}$ on 7F-IMRT were the highest as 1.230, 3.991 respectively(p=0.00). Rectum $D_{25%}$ was similar between 1A-VMAT and 2A-VMAT. But approximately 7% higher value was observed on 7F-IMRT compare to the others(p=0.02) and bladder Dmean were similar among the all plan(P>0.05). Total MU were 494.7, 479.7, 757.9 respectively(P=0.00) for 1A-VMAT, 2A-VMAT, 7F-IMRT and at the most on 7F-IMRT. The delivery time were 65.2sec, 133.1sec, 145.5sec respectively(p=0.00). The obvious shortest time was observed on 1A-VMAT. All plans indicated over 99.5%(p=0.00) of gamma pass rate (2 mm, 2%) in portal dosimetry quality assurance. Conclusion : As a result of study, postoperative prostate cancer radiation therapy for patient using a rectal balloon, there was no significant difference of PTV coverage but 1A-VMAT and 2A-VMAT were more efficient for dose reduction of normal tissue and OARs. Between VMAT plans. $R_{50%}$ and MU were little lower in 2A-VMAT but 1A-VMAT has the shortest delivery time. So it is regarded to be an effective plan and it can reduce intra-fractional motion of patient also.

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A Study on Market Expansion Strategy via Two-Stage Customer Pre-segmentation Based on Customer Innovativeness and Value Orientation (고객혁신성과 가치지향성 기반의 2단계 사전 고객세분화를 통한 시장 확산 전략)

  • Heo, Tae-Young;Yoo, Young-Sang;Kim, Young-Myoung
    • Journal of Korea Technology Innovation Society
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    • v.10 no.1
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    • pp.73-97
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    • 2007
  • R&D into future technologies should be conducted in conjunction with technological innovation strategies that are linked to corporate survival within a framework of information and knowledge-based competitiveness. As such, future technology strategies should be ensured through open R&D organizations. The development of future technologies should not be conducted simply on the basis of future forecasts, but should take into account customer needs in advance and reflect them in the development of the future technologies or services. This research aims to select as segmentation variables the customers' attitude towards accepting future telecommunication technologies and their value orientation in their everyday life, as these factors wilt have the greatest effect on the demand for future telecommunication services and thus segment the future telecom service market. Likewise, such research seeks to segment the market from the stage of technology R&D activities and employ the results to formulate technology development strategies. Based on the customer attitude towards accepting new technologies, two groups were induced, and a hierarchical customer segmentation model was provided to conduct secondary segmentation of the two groups on the basis of their respective customer value orientation. A survey was conducted in June 2006 on 800 consumers aged 15 to 69, residing in Seoul and five other major South Korean cities, through one-on-one interviews. The samples were divided into two sub-groups according to their level of acceptance of new technology; a sub-group demonstrating a high level of technology acceptance (39.4%) and another sub-group with a comparatively lower level of technology acceptance (60.6%). These two sub-groups were further divided each into 5 smaller sub-groups (10 total smaller sub-groups) through two rounds of segmentation. The ten sub-groups were then analyzed in their detailed characteristics, including general demographic characteristics, usage patterns in existing telecom services such as mobile service, broadband internet and wireless internet and the status of ownership of a computing or information device and the desire or intention to purchase one. Through these steps, we were able to statistically prove that each of these 10 sub-groups responded to telecom services as independent markets. We found that each segmented group responds as an independent individual market. Through correspondence analysis, the target segmentation groups were positioned in such a way as to facilitate the entry of future telecommunication services into the market, as well as their diffusion and transferability.

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Effect of Several Herbicides in the Polyethylene - film Mulched Young Mulberry Field (P.E. 필름피복(被覆) 밀식(密植) 뽕밭에서의 수종(數種) 제초제(除草劑) 처리효과(處理效果))

  • Kim, Ho-Rak;Kwon, Yong-Woong;Cho, Yong-Woo
    • Korean Journal of Weed Science
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    • v.5 no.2
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    • pp.202-210
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    • 1985
  • Requirements in weed control in a mulberry field are much similar to those in orchards, but also feature a longer period of weed control of various kinds of persistent weeds, i.e., spring, summer, and winter annuals as well as perennials. In addition the mulberry tree is relatively more sensitive to herbicide injury. Hence, very few herbicides have been used in mulberry field. The present study was conducted to evaluate the usefulness of oxyfluorfen in comparison with alachlor and simazine, which are registered for ordinary mulberry field in Korea, for weed control efficacy in the new, rapidly increasing practice of transparent polyethylene-film mulched and densely planted younger mulberry culture. Dominant spring weeds were Galium spp., Erigeron spp., Polygonum senticosum, and Chenopodium spp. in the non-mulched interbed area in contrast to the Digitaria spp. and Potulaca spp, under mulch. Dominant summer weeds were Digitaria spp., Portulaca spp., Erigeron spp., Artemisia spp. and Calystegia japonica in the non-mulched interbed area while weeds did not occur significantly during summer under mulch which were shaded by vigorously growing mulberry trees. The weeds occurred under mulch in spring reduced shoot growth of young mulberry tree resulting in the reduced yield of mulberry leaves for silkworms. The weeds occurred in the interbed area did not affect until May, but interfered later summer- and fall-growth of mulberry tree. Early single spring application of alachlor(EC), simazine(WP) or oxyfluorfen(EC) at a rate of 650 g, 750 g or 350 g ai per ha, respectively, controlled most annuals satisfactorily to fall in the mulched bed area. In the nonmulched interbed area, however, thrice does of alchlor or simazine was necessary for satisfactory control of spring weeds, followed by summer application of alachlor or simazine at twice dose level as tank mixture with paraquat at 490 g ai per ha for satisfactory control of summer to fall weeds. Single spring application of oxyfluorfen at a rate of 1400 g ai per ha was persistently effective to control satisfactorily even summer and fall weeds. However, heavy rainfall splashed soil borne oxyfluorfen to the lower branch leaves causing some leaf burns. Spring application of oxyfluorfen at a rate of 350 g ai per ha followed by summer application of oxyfluorfen and paraquat tank mixture (350 g ai + 490 g ai) was the best choice for the non-mulched interbed area weed control among the treatments.

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