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Modern Paper Quality Control

  • Olavi Komppa
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2000.06a
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    • pp.16-23
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    • 2000
  • The increasing functional needs of top-quality printing papers and packaging paperboards, and especially the rapid developments in electronic printing processes and various computer printers during past few years, set new targets and requirements for modern paper quality. Most of these paper grades of today have relatively high filler content, are moderately or heavily calendered , and have many coating layers for the best appearance and performance. In practice, this means that many of the traditional quality assurance methods, mostly designed to measure papers made of pure. native pulp only, can not reliably (or at all) be used to analyze or rank the quality of modern papers. Hence, introduction of new measurement techniques is necessary to assure and further develop the paper quality today and in the future. Paper formation , i.e. small scale (millimeter scale) variation of basis weight, is the most important quality parameter of paper-making due to its influence on practically all the other quality properties of paper. The ideal paper would be completely uniform so that the basis weight of each small point (area) measured would be the same. In practice, of course, this is not possible because there always exists relatively large local variations in paper. However, these small scale basis weight variations are the major reason for many other quality problems, including calender blacking uneven coating result, uneven printing result, etc. The traditionally used visual inspection or optical measurement of the paper does not give us a reliable understanding of the material variations in the paper because in modern paper making process the optical behavior of paper is strongly affected by using e.g. fillers, dye or coating colors. Futhermore, the opacity (optical density) of the paper is changed at different process stages like wet pressing and calendering. The greatest advantage of using beta transmission method to measure paper formation is that it can be very reliably calibrated to measure true basis weight variation of all kinds of paper and board, independently on sample basis weight or paper grade. This gives us the possibility to measure, compare and judge papers made of different raw materials, different color, or even to measure heavily calendered, coated or printed papers. Scientific research of paper physics has shown that the orientation of the top layer (paper surface) fibers of the sheet paly the key role in paper curling and cockling , causing the typical practical problems (paper jam) with modern fax and copy machines, electronic printing , etc. On the other hand, the fiber orientation at the surface and middle layer of the sheet controls the bending stiffness of paperboard . Therefore, a reliable measurement of paper surface fiber orientation gives us a magnificent tool to investigate and predict paper curling and coclking tendency, and provides the necessary information to finetune, the manufacturing process for optimum quality. many papers, especially heavily calendered and coated grades, do resist liquid and gas penetration very much, bing beyond the measurement range of the traditional instruments or resulting invonveniently long measuring time per sample . The increased surface hardness and use of filler minerals and mechanical pulp make a reliable, nonleaking sample contact to the measurement head a challenge of its own. Paper surface coating causes, as expected, a layer which has completely different permeability characteristics compared to the other layer of the sheet. The latest developments in sensor technologies have made it possible to reliably measure gas flow in well controlled conditions, allowing us to investigate the gas penetration of open structures, such as cigarette paper, tissue or sack paper, and in the low permeability range analyze even fully greaseproof papers, silicon papers, heavily coated papers and boards or even detect defects in barrier coatings ! Even nitrogen or helium may be used as the gas, giving us completely new possibilities to rank the products or to find correlation to critical process or converting parameters. All the modern paper machines include many on-line measuring instruments which are used to give the necessary information for automatic process control systems. hence, the reliability of this information obtained from different sensors is vital for good optimizing and process stability. If any of these on-line sensors do not operate perfectly ass planned (having even small measurement error or malfunction ), the process control will set the machine to operate away from the optimum , resulting loss of profit or eventual problems in quality or runnability. To assure optimum operation of the paper machines, a novel quality assurance policy for the on-line measurements has been developed, including control procedures utilizing traceable, accredited standards for the best reliability and performance.

A Case of Childhood Obstructive Sleep Apnea Syndrome with Co-morbid Attention Deficit Hyperactivity Disorder Treated with Continuous Positive Airway Pressure Treatment (지속적(持續的) 상기도(上氣道) 양압술(陽壓術)을 시행(施行)하여 치료효과(治療效果)를 본 주의력(注意力) 결핍(缺乏).과잉(過剩) 운동장애(運動障碍)를 동반(同伴)한 소아기(小兒基) 폐쇄성(閉鎖性) 수면무호흡증(睡眠無呼吸症) 1례(例))

  • Sohn, Chang-Ho;Shin, Min-Sup;Hong, Kang-E;Jeong, Do-Un
    • Sleep Medicine and Psychophysiology
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    • v.3 no.1
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    • pp.85-95
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    • 1996
  • Obstructive sleep apnea syndrome(OSAS) in childhood is unique and different n-om that in adulthood in several aspects, including pathophysiology, clinical features, diagnostic criteria, complications, management, and prognosis. Characteristic features of childhood OSAS in comparison with the adult form are the variety of severe complications such as developmental delay, more prominent behavioral and cognitive impairments, vivid cardiovascular symptoms, and increased death risk, warranting a special attention to the possible diagnosis of OSAS in children who snore. However, the childhood OSAS is often neglected and unrecognized. We, therefore, report a case of very severe OSAS in a 5-year-old boy who was sucessfully treated with continuous positive airway pressure(CPAP) treatment. Interestingly, the patient was comor-bid with the attention deficit hyperactivity disorder. Prior to the initial visit to us, adenotonsillectomy had been done at the age of 4 with no significant improvement of apneic symptoms and heavy snoring. On the initial diagnostic procedures, marked degree of snoring was audible even in the daytime wake state and the patient was observed to be very hyperactive. Increased pulmonary vascularity with borderline cardiomegaly was noted on chest X-ray. The baseline polysomnography revealed that the patient was very sleep-apneic and snored very heavily, with the respiratory disturbance index(RDI) of 46.9 per hour of sleep, the mean SaO2 of 78.8%, and the lowest SaO2 of 40.0%(the lowest detectable oxygen level by the applied oxymeter). The second night polysomnography was done for CPAP titration and the optimal pressure turned out to be $8.0\;cmH_2O$. The applied CPAP treatment was well tolerated by the patient and was found to be very effective in alleviating heavy snoring and severe repetitive sleep apneas. After 18 months of the CPAP treatment, the patient was followed up with nocturnal polysomnography(baseline and CPAP nights) and clinical examination. Sleep apneas were still present without CPAP on the baseline night. However, the severity of OSAS was significantly decreased(RDI of 15.7, mean SaO2 of 96.2%, and the lowest SaO2 of 83.0%), compared to the initial polysomnographic findings before initiation of long-term CPAP treatment. Wechsler intelligence tests done before and after the CPAP treatment were compared with each other and surprising improvement of intelligence(total 9 points, performance 16 points) was noted. Clinically he was found to be markedly improved in his attention deficit hyperactive behavior after CPAP treatment, but with minimal change of TOVA(test of variables of attention) scores except conversion of reaction time score into normal range. On the chest X-ray taken after 18 months of CPAP application, the initial cardiopulmonary abnormalities were not found at all. We found that the CPAP treatment in a young child is very effective, safe, and well-tolerated and also improves the co-morbid attention deficit hyperactive symptoms. Overall, the growth and development of the child has been facilitated with the long-term use of CPAP. Cardiovascular complications induced by OSAS have been also normalized with CPAP treatment. We suggest that early diagnosis and active treatment intervention of OSAS in children are crucial in preventing and ameliorating possible serious complications caused by repetitive sleep apneas and consequent hypoxic damage during sleep.

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Job Preference Analysis and Job Matching System Development for the Middle Aged Class (중장년층 일자리 요구사항 분석 및 인력 고용 매칭 시스템 개발)

  • Kim, Seongchan;Jang, Jincheul;Kim, Seong Jung;Chin, Hyojin;Yi, Mun Yong
    • Journal of Intelligence and Information Systems
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    • v.22 no.4
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    • pp.247-264
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    • 2016
  • With the rapid acceleration of low-birth rate and population aging, the employment of the neglected groups of people including the middle aged class is a crucial issue in South Korea. In particular, in the 2010s, the number of the middle aged who want to find a new job after retirement age is significantly increasing with the arrival of the retirement time of the baby boom generation (born 1955-1963). Despite the importance of matching jobs to this emerging middle aged class, private job portals as well as the Korean government do not provide any online job service tailored for them. A gigantic amount of job information is available online; however, the current recruiting systems do not meet the demand of the middle aged class as their primary targets are young workers. We are in dire need of a specially designed recruiting system for the middle aged. Meanwhile, when users are searching the desired occupations on the Worknet website, provided by the Korean Ministry of Employment and Labor, users are experiencing discomfort to search for similar jobs because Worknet is providing filtered search results on the basis of exact matches of a preferred job code. Besides, according to our Worknet data analysis, only about 24% of job seekers had landed on a job position consistent with their initial preferred job code while the rest had landed on a position different from their initial preference. To improve the situation, particularly for the middle aged class, we investigate a soft job matching technique by performing the following: 1) we review a user behavior logs of Worknet, which is a public job recruiting system set up by the Korean government and point out key system design implications for the middle aged. Specifically, we analyze the job postings that include preferential tags for the middle aged in order to disclose what types of jobs are in favor of the middle aged; 2) we develope a new occupation classification scheme for the middle aged, Korea Occupation Classification for the Middle-aged (KOCM), based on the similarity between jobs by reorganizing and modifying a general occupation classification scheme. When viewed from the perspective of job placement, an occupation classification scheme is a way to connect the enterprises and job seekers and a basic mechanism for job placement. The key features of KOCM include establishing the Simple Labor category, which is the most requested category by enterprises; and 3) we design MOMA (Middle-aged Occupation Matching Algorithm), which is a hybrid job matching algorithm comprising constraint-based reasoning and case-based reasoning. MOMA incorporates KOCM to expand query to search similar jobs in the database. MOMA utilizes cosine similarity between user requirement and job posting to rank a set of postings in terms of preferred job code, salary, distance, and job type. The developed system using MOMA demonstrates about 20 times of improvement over the hard matching performance. In implementing the algorithm for a web-based application of recruiting system for the middle aged, we also considered the usability issue of making the system easier to use, which is especially important for this particular class of users. That is, we wanted to improve the usability of the system during the job search process for the middle aged users by asking to enter only a few simple and core pieces of information such as preferred job (job code), salary, and (allowable) distance to the working place, enabling the middle aged to find a job suitable to their needs efficiently. The Web site implemented with MOMA should be able to contribute to improving job search of the middle aged class. We also expect the overall approach to be applicable to other groups of people for the improvement of job matching results.

A Study on the Performance Evaluation of G2B Procurement Process Innovation by Using MAS: Korea G2B KONEPS Case (멀티에이전트시스템(MAS)을 이용한 G2B 조달 프로세스 혁신의 효과평가에 관한 연구 : 나라장터 G2B사례)

  • Seo, Won-Jun;Lee, Dae-Cheor;Lim, Gyoo-Gun
    • Journal of Intelligence and Information Systems
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    • v.18 no.2
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    • pp.157-175
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    • 2012
  • It is difficult to evaluate the performance of process innovation of e-procurement which has large scale and complex processes. The existing evaluation methods for measuring the effects of process innovation have been mainly done with statistically quantitative methods by analyzing operational data or with qualitative methods by conducting surveys and interviews. However, these methods have some limitations to evaluate the effects because the performance evaluation of e-procurement process innovation should consider the interactions among participants who are active either directly or indirectly through the processes. This study considers the e-procurement process as a complex system and develops a simulation model based on MAS(Multi-Agent System) to evaluate the effects of e-procurement process innovation. Multi-agent based simulation allows observing interaction patterns of objects in virtual world through relationship among objects and their behavioral mechanism. Agent-based simulation is suitable especially for complex business problems. In this study, we used Netlogo Version 4.1.3 as a MAS simulation tool which was developed in Northwestern University. To do this, we developed a interaction model of agents in MAS environment. We defined process agents and task agents, and assigned their behavioral characteristics. The developed simulation model was applied to G2B system (KONEPS: Korea ON-line E-Procurement System) of Public Procurement Service (PPS) in Korea and used to evaluate the innovation effects of the G2B system. KONEPS is a successfully established e-procurement system started in the year 2002. KONEPS is a representative e-Procurement system which integrates characteristics of e-commerce into government for business procurement activities. KONEPS deserves the international recognition considering the annual transaction volume of 56 billion dollars, daily exchanges of electronic documents, users consisted of 121,000 suppliers and 37,000 public organizations, and the 4.5 billion dollars of cost saving. For the simulation, we analyzed the e-procurement of process of KONEPS into eight sub processes such as 'process 1: search products and acquisition of proposal', 'process 2 : review the methods of contracts and item features', 'process 3 : a notice of bid', 'process 4 : registration and confirmation of qualification', 'process 5 : bidding', 'process 6 : a screening test', 'process 7 : contracts', and 'process 8 : invoice and payment'. For the parameter settings of the agents behavior, we collected some data from the transactional database of PPS and some information by conducting a survey. The used data for the simulation are 'participants (government organizations, local government organizations and public institutions)', 'the number of bidding per year', 'the number of total contracts', 'the number of shopping mall transactions', 'the rate of contracts between bidding and shopping mall', 'the successful bidding ratio', and the estimated time for each process. The comparison was done for the difference of time consumption between 'before the innovation (As-was)' and 'after the innovation (As-is).' The results showed that there were productivity improvements in every eight sub processes. The decrease ratio of 'average number of task processing' was 92.7% and the decrease ratio of 'average time of task processing' was 95.4% in entire processes when we use G2B system comparing to the conventional method. Also, this study found that the process innovation effect will be enhanced if the task process related to the 'contract' can be improved. This study shows the usability and possibility of using MAS in process innovation evaluation and its modeling.

Perfluoropolymer Membranes of Tetrafluoroethylene and 2,2,4Trifluofo- 5Trifluorometoxy- 1,3Dioxole.

  • Arcella, V.;Colaianna, P.;Brinati, G.;Gordano, A.;Clarizia, G.;Tocci, E.;Drioli, E.
    • Proceedings of the Membrane Society of Korea Conference
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    • 1999.07a
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    • pp.39-42
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    • 1999
  • Perfluoropolymers represent the ultimate resistance to hostile chemical environments and high service temperature, attributed to the presence of fluorine in the polymer backbone, i.e. to the high bond energy of C-F and C-C bonds of fluorocarbons. Copolymers of Tetrafluoroethylene (TEE) and 2, 2, 4Trifluoro-5Trifluorometoxy- 1, 3Dioxole (TTD), commercially known as HYFLON AD, are amorphous perfluoropolymers with glass transition temperature (Tg)higher than room temperature, showing a thermal decomposition temperature exceeding 40$0^{\circ}C$. These polymer systems are highly soluble in fluorinated solvents, with low solution viscosities. This property allows the preparation of self-supported and composite membranes with desired membrane thickness. Symmetric and asymmetric perfluoropolymer membranes, made with HYFLON AD, have been prepared and evaluated. Porous and not porous symmetric membranes have been obtained by solvent evaporation with various processing conditions. Asymmetric membranes have been prepared by th wet phase inversion method. Measure of contact angle to distilled water have been carried out. Figure 1 compares experimental results with those of other commercial membranes. Contact angles of about 120$^{\circ}$for our amorphous perfluoropolymer membranes demonstrate that they posses a high hydrophobic character. Measure of contact angles to hexandecane have been also carried out to evaluate the organophobic character. Rsults are reported in Figure 2. The observed strong organophobicity leads to excellent fouling resistance and inertness. Porous membranes with pore size between 30 and 80 nanometers have shown no permeation to water at pressures as high as 10 bars. However high permeation to gases, such as O2, N2 and CO2, and no selectivities were observed. Considering the porous structure of the membrane, this behavior was expected. In consideration of the above properties, possible useful uses in th field of gas- liquid separations are envisaged for these membranes. A particularly promising application is in the field of membrane contactors, equipments in which membranes are used to improve mass transfer coefficients in respect to traditional extraction and absorption processes. Gas permeation properties have been evaluated for asymmetric membranes and composite symmetric ones. Experimental permselectivity values, obtained at different pressure differences, to various single gases are reported in Tab. 1, 2 and 3. Experimental data have been compared with literature data obtained with membranes made with different amorphous perfluoropolymer systems, such as copolymers of Perfluoro2, 2dimethyl dioxole (PDD) and Tetrafluorethylene, commercialized by the Du Pont Company with the trade name of Teflon AF. An interesting linear relationship between permeability and the glass transition temperature of the polymer constituting the membrane has been observed. Results are descussed in terms of polymer chain structure, which affects the presence of voids at molecular scale and their size distribution. Molecular Dyanmics studies are in progress in order to support the understanding of these results. A modified Theodoru- Suter method provided by the Amorphous Cell module of InsightII/Discover was used to determine the chain packing. A completely amorphous polymer box of about 3.5 nm was considered. Last but not least the use of amorphous perfluoropolymer membranes appears to be ideal when separation processes have to be performed in hostile environments, i.e. high temperatures and aggressive non-aqueous media, such as chemicals and solvents. In these cases Hyflon AD membranes can exploit the outstanding resistance of perfluoropolymers.

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The Health Status of Rural Farming Women (농촌여성(農村女性)의 건강실태(健康實態)에 관한 연구(硏究))

  • Park, Jung-Eun
    • Journal of agricultural medicine and community health
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    • v.15 no.2
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    • pp.97-106
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    • 1990
  • 1. Background Women's health and their involvement in health care are essential to health for everyone. If they are ignorant, malnourished or over-worked, the health &-their families as well as their own health will suffer. Women's health depends on broad considerations beyond medicine. Among other things, it depends upon their work in farming. their subordination to their families, their accepted roles, and poor hygiene with poorly equipped housing and environmental sanitation. 2. Objectives and Contents a. The health status of rural women : physical and mental complaints, experience of pesticides intoxication, Farmer's syndrome, experiences of reproductive health problems. b. participation in and attitudes towards housework and farming c. accessibility of medical care d. status of maternal health : fertility, family planning practice. induced abortion, and maternal care 3. Research method A nationwide field survey, based on stratified random sampling, was conducted during July, 1986. Revised Cornell Medical index(68 out of 195 items). Kawagai's Farmers Syndrome Scale, and self-developed structured questionnaires were used to rural farming wives(n=2.028). aged between 26-55. 4. Characteristics of the respondents mean age : 40.2 marital status : 90.8% married mean no. of household : 4.9 average years of education : 4.7 yrs. average income of household : \235,000 average years of residence in rural area : 36.4 yrs average Working hours(household and farming) : 11 hrs. 23 min 5. Health Status of rural women a. The average number of physical and mental symptoms were 12.4, 4.7, and the rate of complaints were 22.1%, 38.8% each. revealing complaints of mental symptomes higher than physical ones. b. 65.4% of rural women complained of more than 4 symptoms out of 9, indicating farmer's syndrome. 11.9 % experienced pesticide overdue syndrome c. 57.6% of respondents experienced women-specific health problems. d. Age and education of respondents were the variables which affect on the level of their health 6. Utilization of medical services a. The number of symptoms and complaints of respondents were dependent on the distance to where the health-care service is given b. Drug store was the most commonly utilized due to low price and the distance to reach. while nurse practitioners were well utilized when there were nurse practitioner's office in their villages. c. Rural women were internalized their subordination to husbands and children, revealing they are positive(93%) in health-care demand for-them but negative(30%) for themselves d. 33.0% of respondents were habitual drug users, 4.5% were smokers and 32.3% were alcohol drinkers. and 86.3% experienced induced-abortion. But most of them(77.6%) knew that those had negative effects on health. 7. Maternal Health Care a. Practice rate of contraception was 48.1% : female users were 90.9% in permanent and 89.6% in temporary contraception b. Induced abortions were taken mostly at hospital(86.3%), while health centers(4.7%), midwiferies(4.3%). and others(4.5%) including drug stores were listed a few. The repeated numbers of induced abortion seemed affected on the increasing numbers of symptoms and complaints. c. The first pre-natal check-up during first trimester was 41.8%, safe delivery rate was 15.6%, post-natal check-up during two months after delivery. Rural women had no enough rest after delivery revealing average days of rest from home work and farming 8.3 and 17.2. d. 86.6% practised breast feeding, showing younger and more educated mothers depending on artificial milk 8. Recommendations a. To lessen the multiple role over burden housing and sanitary conditions should be improved, and are needed farming machiner es for women and training on the use of them b. Health education should begin at primary school including health behavior and living environment. c. Women should be encouraged to become policy-makers as well as administrators in the field of women specific health affairs. d. Women's health indicators should be developed and women's health surveillance system too.

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Weights for Evaluation items of Conformity index of Bird breeding sites on the West and South coasts of Korea (서·남해 연안성 조류번식지 적합성지수 평가항목 가중치 설정)

  • Kim, Chang-Hyeon;Kim, Won-Bin;Kim, Kyou-Sub;Lee, Chang-Hun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.41 no.4
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    • pp.40-48
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    • 2023
  • This study is part of a foundational research effort aimed at developing a suitability index for breeding grounds related to avian activities along the domestic South and West coasts, including islands. Focus Group Interviews (FGI) and Analytic Hierarchy Process (AHP) analyses were conducted. The results are as follows. First, as a result of determining the value of the suitability of coastal bird breeding sites, the 'Natural Value(0.763)' was higher than the 'Artificial Value(0.237)'. Other artificial values were identified as sub-ranked except for 'Protected Areas' to ensure continuous integrity of breeding spaces. Second, as a result of re-establishing the 25 evaluation items classified in the two-time FGI as higher concepts, nine natural values and five artificial values were finally selected as a total of 14. Third, the results of the mid-classification evaluation of the importance of the suitability of coastal bird breeding sites were identified in the order of 'Ecological Value(0.392)', 'Topographic Value(0.251)', 'Passive Interference(0.124)', 'Geological Value(0.120)', and 'Active Interference(0.113)'. Fourth, the results of the priority of evaluation items of coastal bird breeding sites were in the order of 'Vegetation Distribution (0.187)', 'Area of Mudflats(0.118)', 'Presence or Absence of Mudflats(0.092)', 'Appearance of Natural Enemies(0.087)', 'Protected Areas(0.08)', 'Island Area (0.069)', 'Over-Breeding devastation(0.064)', 'Soil Composition Ratio(0.056)', 'Distance from Land(0.054)', 'Ocean farm area (0.045)', 'Cultivated land area(0.041)', 'Cultivation behavior(0.038)', 'Angle of the Surface(0.036)', and 'Land Use(0.033)'. It is judged that the weighting result value of the evaluation items derived in this study can be used for priority evaluation focusing on the coastal bird breeding area space. However, it seems that the correlation with the unique habitat suitability of bird individuals needs to be supplemented, and spatial analysis research incorporating species-specific characteristics will be left as a future task.

Optimal Selection of Classifier Ensemble Using Genetic Algorithms (유전자 알고리즘을 이용한 분류자 앙상블의 최적 선택)

  • Kim, Myung-Jong
    • Journal of Intelligence and Information Systems
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    • v.16 no.4
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    • pp.99-112
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    • 2010
  • Ensemble learning is a method for improving the performance of classification and prediction algorithms. It is a method for finding a highly accurateclassifier on the training set by constructing and combining an ensemble of weak classifiers, each of which needs only to be moderately accurate on the training set. Ensemble learning has received considerable attention from machine learning and artificial intelligence fields because of its remarkable performance improvement and flexible integration with the traditional learning algorithms such as decision tree (DT), neural networks (NN), and SVM, etc. In those researches, all of DT ensemble studies have demonstrated impressive improvements in the generalization behavior of DT, while NN and SVM ensemble studies have not shown remarkable performance as shown in DT ensembles. Recently, several works have reported that the performance of ensemble can be degraded where multiple classifiers of an ensemble are highly correlated with, and thereby result in multicollinearity problem, which leads to performance degradation of the ensemble. They have also proposed the differentiated learning strategies to cope with performance degradation problem. Hansen and Salamon (1990) insisted that it is necessary and sufficient for the performance enhancement of an ensemble that the ensemble should contain diverse classifiers. Breiman (1996) explored that ensemble learning can increase the performance of unstable learning algorithms, but does not show remarkable performance improvement on stable learning algorithms. Unstable learning algorithms such as decision tree learners are sensitive to the change of the training data, and thus small changes in the training data can yield large changes in the generated classifiers. Therefore, ensemble with unstable learning algorithms can guarantee some diversity among the classifiers. To the contrary, stable learning algorithms such as NN and SVM generate similar classifiers in spite of small changes of the training data, and thus the correlation among the resulting classifiers is very high. This high correlation results in multicollinearity problem, which leads to performance degradation of the ensemble. Kim,s work (2009) showedthe performance comparison in bankruptcy prediction on Korea firms using tradition prediction algorithms such as NN, DT, and SVM. It reports that stable learning algorithms such as NN and SVM have higher predictability than the unstable DT. Meanwhile, with respect to their ensemble learning, DT ensemble shows the more improved performance than NN and SVM ensemble. Further analysis with variance inflation factor (VIF) analysis empirically proves that performance degradation of ensemble is due to multicollinearity problem. It also proposes that optimization of ensemble is needed to cope with such a problem. This paper proposes a hybrid system for coverage optimization of NN ensemble (CO-NN) in order to improve the performance of NN ensemble. Coverage optimization is a technique of choosing a sub-ensemble from an original ensemble to guarantee the diversity of classifiers in coverage optimization process. CO-NN uses GA which has been widely used for various optimization problems to deal with the coverage optimization problem. The GA chromosomes for the coverage optimization are encoded into binary strings, each bit of which indicates individual classifier. The fitness function is defined as maximization of error reduction and a constraint of variance inflation factor (VIF), which is one of the generally used methods to measure multicollinearity, is added to insure the diversity of classifiers by removing high correlation among the classifiers. We use Microsoft Excel and the GAs software package called Evolver. Experiments on company failure prediction have shown that CO-NN is effectively applied in the stable performance enhancement of NNensembles through the choice of classifiers by considering the correlations of the ensemble. The classifiers which have the potential multicollinearity problem are removed by the coverage optimization process of CO-NN and thereby CO-NN has shown higher performance than a single NN classifier and NN ensemble at 1% significance level, and DT ensemble at 5% significance level. However, there remain further research issues. First, decision optimization process to find optimal combination function should be considered in further research. Secondly, various learning strategies to deal with data noise should be introduced in more advanced further researches in the future.

AN OBSERVATIONAL MULTI-CENTER STUDY FOR EVALUATION OF EFFICACY, SAFETY AND PARENTAL SATISFACTION OF METHYLPHENIDATE-OROS IN CHILDREN WITH ADHD (주의력결핍과잉운동장애 아동에게 Methylphenidate-OROS 투여시 효용성과 안전성 및 부모 만족도를 평가하기 위한 다기관관찰연구)

  • Kim, Bong-Seog;Park, Eun-Jin
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.16 no.2
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    • pp.279-285
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    • 2005
  • Objectives : This study was performed to evaluate the efficacy and safety of MPH-OROS and parental satisfaction for treatment of children with ADHD Method : The 569 participants were clinically diagnosed for ADHD using DSM-IV criteria. We switched current medication to MPH-OROS or introduced MPH-OROS for treatment of ADHD. We assessed the clinical global impression severity of illness (CGI-S), the clinical global impression severity of improvement(CGI-I). And the parents of participants measured the Korean version of Conners rating scale at baseline, the 1 st week and the 3rd week after MPH-OROS trial. At the 3rd week, the parents measured the parent satisfaction questionnaire. Results : $13\%$ of participants dropped out because of several causes including side effects. The change of CGI-S was significantly decreased. Using CGI-I, the improvement was $72.3\%$ at the 1st week and $87.4\%$ at the 3rd week. The total score of the Korean version of Conners parent rating scale was significantly decreased. The participants complaining one or more of side effects were 119$(20.7\%)$, and the most common side effect was anorexia. The $94\%$ of parents replied that they were overall satisfied with MPH-OROS trial. Also the advantages of MPH-OROS of parental report were the long duration of the drug, the improvement of schoolwork and attitude, the improvement of home behavior and homework and the improvement of overactivity. Conclusion : MPH-OROS is effective and well-tolerated in actual clinical use for ADHD.

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A Review on the Background of Takjok(濯足; Washing Feet) and the Landscape Architectual Meaning of Its Cultural Phenomenon - Focused on Takjokjiyu(濯足之遊) Shown on Poetry, Prose, and Painting - (탁족(濯足)의 배경과 그 문화현상에 담긴 조경적 의미 - 시문과 그림에 나타난 탁족지유(濯足之遊)를 중심으로 -)

  • Rho, Jae-Hyun;Seo, Hyo-Seog;Choi, Jong-Hee
    • Journal of the Korean Institute of Landscape Architecture
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    • v.41 no.6
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    • pp.72-83
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    • 2013
  • This study suggests the necessity of landscaping alternatives for the succession of Takjok(濯足) culture by considering the background and meaning of Takjok's cultural phenomenon shown in old literatures and paintings and its result is as follows. An old idiom, 'Takyoung Takjok(濯纓濯足)' implying a disinterested living attitude from the mundane world and an attitude complying with nature, has been sublimated to 'Takjokjiyu(濯足之遊)' which means living in comfortable retirement through life in seclusion(隱逸). Classical scholars immerse their feet in soft-flowing(柔軟) water for 'Mulailche(物我一體; synchronized with nature)' which is a unified condition with 'Do(道; truth)' and connected to the stage of 'Yu(遊)', a free mental state, and its nature. The cultural phenomenon of Takjok appeared in the inherited landscape paintings in the Joseon dynasty period after the late stage of Koryo. Takjok shown in 'Pal Kyung Shi'(八景詩; poetry singing for the eight scenary) was described as not a transcendent scene, but as a scenery of daily life. Dense forest and water, such as a stream with clean water, rocks, and pine trees shown in Takjok paintings have been symbolized as a seclusion space for classical scholars with higher thinking and their mental states have been more emerged. Mental pleasures called as seclusion and Takjokjiyu have been relatively emphasized in the Takjok paintings of the Joseon Dynasty period contrary to the Chinese Takjok paintings emphasizing Chung Gye(淸溪; clean stream) and Chang Rang(滄浪; high and clean wave) and strongly representing the image of 'Chung Ryu'(淸流; clean flowing water) and the veneration for antiquity. The view of nature described in the Takjok paintings represents the provision of nature as a situation and attitudes of classical scholars and implies a Taoism perspective which describes the 'do' of nature. This view of nature itself remained intact(無爲自然) with the love of mountains and water, showing a side of the zeitgeist and aesthetic consciousness of China and Joseon. The 'Takjokjiyu' of both countries has be interpreted as a symbol of personality development, behavior, life in seclusion, or transcending the mundane world and has also been accepted as a method of summer vacation in the real world. It should be considered that Takjok includes ordinary people's wisdom to resist the hot weather, as well as the classical scholar's ideal and the veneration of antiquity. From this perspective, water space, Takjok rocks, and the use of water based on the environmental supportability should be newly focused as a recreational space and it reminds us that the spirit of Takjok is a classical mental healing method.