• Journal of Bio-Environment Control
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• v.29 no.3
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• pp.209-218
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• 2020

This paper investigated actual crop evapotranspiration (ET_c) of tomato and paprika planted in test beds of the greenhouse. Crop water requirement (CWR) is the amount of water required to compensate ET_c loss from the crop. The main objectives of the study are to assess whether the actual crop watering (ACW) was adequate CWR of tomato and paprika and which amount of ACW should be irrigated to each crop. ET_c was estimated using the Penman-Monteith model (P-M) for each crop. ACW was calculated from the difference of amount of nutrient supply water and amount of nutrient drainage water. ACW and CWR of each crop were determined, compared and assessed. Results indicated CWR-tomato was around 100 to 1,200 ml/day, while CWR-paprika ranged from 100 to 500 ml/day. Comparison of ACW and CWR of each crop found that the difference of ACW and CWR are fluctuated following day of planting (DAP). However, the differences could divide into two phases, first the amount of ACWs of each crop are less than CWR in the initial phase (60 DAP) around 500 ml/day and 91 ml/day, respectively. Then, ACWs of each crop are greater than the CWR after 60 DAP until the end of cultivation approximately 400 ml/day in tomato and 178 ml/day in paprika. ET_c assessment is necessary to correctly quantify crop irrigation water needs and it is an accurate short-term estimation of CWR in greenhouse for optimal irrigation scheduling. Thus, reducing ACW of tomato and paprika in the greenhouse is a recommendation. The amount of ACW of tomato should be applied from 100 to 1,200 ml/day and paprika is 100 to 500 ml/day depend on DAP.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.141-150
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• 2012

This paper suggests a critical path search algorithm that can easily draw PERT/GANTT chart which manages and plans a project schedule. In order to evaluate a critical path that determines the project schedule, Critical Path Method (CPM) is generally utilized. However, CPM undergoes 5 stages to calculate the critical path for a network diagram that is previously designed according to correlative relationship and execution period of project execution activities. And it may not correctly evaluate $T_E$ (The Earliest Time), since it does not suggest the way how to determine the sequence of the nodes activities that calculate the $T_E$. Also, the sequence of the network diagram activities obtained from CPM cannot be visually represented, and hence Lucko suggested an algorithm which undergoes 9 stages. On the other hand, the suggested algorithm, first of all, decides the sequence in advance, by reallocating the nodes into levels after Breadth-First Search of the network diagram that is previously designed. Next, it randomly chooses nodes of each level and immediately determines the critical path only after calculation of $T_E$. Finally, it enables the representation of the execution sequence of the project activity to be seen precisely visual by means of a small movement of $T_E$ of the nodes that are not belonging to the critical path, on basis of the $T_E$ of the nodes which belong to the critical path. The suggested algorithm has been proved its applicability to 10 real project data. It is able to get the critical path from all the projects, and precisely and visually represented the execution sequence of the activities. Also, this has advantages of, firstly, reducing 5 stages of CPM into 1, simplifying Lucko's 9 stages into 2 stages that are used to clearly express the execution sequence of the activities, and directly converting the representation into PERT/GANTT chart.

• Journal of Intelligence and Information Systems
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• v.16 no.4
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• pp.131-145
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• 2010

The framework for making a coordinated decision for large-scale facilities has become an important issue in supply chain(SC) management research. The competitive business environment requires companies to continuously search for the ways to achieve high efficiency and lower operational costs. In the areas of production/distribution planning, many researchers and practitioners have developedand evaluated the deterministic models to coordinate important and interrelated logistic decisions such as capacity management, inventory allocation, and vehicle routing. They initially have investigated the various process of SC separately and later become more interested in such problems encompassing the whole SC system. The accurate quotation of ATP(Available-To-Promise) plays a very important role in enhancing customer satisfaction and fill rate maximization. The complexity for intelligent manufacturing system, which includes all the linkages among procurement, production, and distribution, makes the accurate quotation of ATP be a quite difficult job. In addition to, many researchers assumed ATP model with integer time. However, in industry practices, integer times are very rare and the model developed using integer times is therefore approximating the real system. Various alternative models for an ATP system with time lags have been developed and evaluated. In most cases, these models have assumed that the time lags are integer multiples of a unit time grid. However, integer time lags are very rare in practices, and therefore models developed using integer time lags only approximate real systems. The differences occurring by this approximation frequently result in significant accuracy degradations. To introduce the ATP model with time lags, we first introduce the dynamic production function. Hackman and Leachman's dynamic production function in initiated research directly related to the topic of this paper. They propose a modeling framework for a system with non-integer time lags and show how to apply the framework to a variety of systems including continues time series, manufacturing resource planning and critical path method. Their formulation requires no additional variables or constraints and is capable of representing real world systems more accurately. Previously, to cope with non-integer time lags, they usually model a concerned system either by rounding lags to the nearest integers or by subdividing the time grid to make the lags become integer multiples of the grid. But each approach has a critical weakness: the first approach underestimates, potentially leading to infeasibilities or overestimates lead times, potentially resulting in excessive work-inprocesses. The second approach drastically inflates the problem size. We consider an optimized ATP system with non-integer time lag in supply chain management. We focus on a worldwide headquarter, distribution centers, and manufacturing facilities are globally networked. We develop a mixed integer programming(MIP) model for ATP process, which has the definition of required data flow. The illustrative ATP module shows the proposed system is largely affected inSCM. The system we are concerned is composed of a multiple production facility with multiple products, multiple distribution centers and multiple customers. For the system, we consider an ATP scheduling and capacity allocationproblem. In this study, we proposed the model for the ATP system in SCM using the dynamic production function considering the non-integer time lags. The model is developed under the framework suitable for the non-integer lags and, therefore, is more accurate than the models we usually encounter. We developed intelligent ATP System for this model using genetic algorithm. We focus on a capacitated production planning and capacity allocation problem, develop a mixed integer programming model, and propose an efficient heuristic procedure using an evolutionary system to solve it efficiently. This method makes it possible for the population to reach the approximate solution easily. Moreover, we designed and utilized a representation scheme that allows the proposed models to represent real variables. The proposed regeneration procedures, which evaluate each infeasible chromosome, makes the solutions converge to the optimum quickly.

• Journal of dental hygiene science
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• v.4 no.3
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• pp.117-126
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• 2004

For a month of September, 2004, a questionnaire regarding dental hygiene was distributed to 165 workers of Ulsan area. A total of 125 questionnaire were analyzed: 102 collected of the distributed 165 pieces, and 23 questionnaires reported by patients of a dental clinic in Dong-gu, Woolsan. The result is as follows; (1) Labor workers of Ulsan have thought that they are in good dental health, 44.1% of respondents, following by those who they believe they are in moderate health and those who they think are in poor condition. 89.0% of total workers have experienced dental treatment. (2) Regarding the location of dental treatment, 85.0% of respondents have pointed out dental hospitals and clinics, while 3.9% have indicated that they had treatment from unlicensed dentists. Specifically, workers in their 40s over have ever experienced dental treatment by unlicensed dentists. Those who think they are in poor dental condition have tended to have more dental treatment by unlicensed dentists. (3) Regarding the reason that they put off the treatment, 59.1% of respondents have indicated that they have no time to have the treatment, following by economic burden and the lack of confidence in dentists. When they have tooth aches or the gum ache, 60% of respondents have suggested that they endure the ache or take a medicine to alleviate the pain, showing a lower understanding of early dental treatment. (4) Regarding the reason why they are unwilling to go to dentists, respondents have revealed the anxiety against pain, 50.4%, following by the difficulty of scheduling and unsatisfied services. (5) 47.2% of respondents have brushed their teeth 3 times everyday, following by those who have done it 2 times a day and those one a day. Regarding how to brush the teeth, most of respondents have brushed their teeth in the upper, lower, and the both side, 61.4%. The younger respondents and those who think they are in good dental health have tended to brush their teeth up and down. (6) Regarding the cause of the gum disease, 67.7% of respondents have thought that it is caused by poor dental hygiene, following by natural occurrence due to age, hereditary nature, and physical predisposition. (7) 67.7% of respondents have experienced dental scaling, while 32.3% of them have had no experience in it. 53.5% of workers have thought that scaling may not be recommended since they have the teeth scaled periodically once they had dental scaling, a higher rate than 46.5% who think scaling is good for the gum health.

• Journal of Broadcast Engineering
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• v.24 no.1
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• pp.118-131
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• 2019

In order to provide 8K UHD contents of terrestrial broadcasting with a large capacity, the terrestrial broadcasting system has various problems such as limited bandwidth and so on. To solve these problems, UHD contents transmission technology has been actively studied, and an 8K UHD broadcasting system using terrestrial broadcasting network and communication network has been proposed. The proposed technique is to solve the limited bandwidth problem of terrestrial broadcasting network by segmenting 8K UHD contents and transmitting them to heterogeneous networks through hierarchical separation. Through the terrestrial broadcasting network, the base layer corresponding to FHD and the additional enhancement layer data for 4K UHD are transmitted, and the additional enhancement layer data corresponding to 8K UHD is transmitted through the communication network. When 8K UHD contents are provided in such a way, user can receive up to 4K UHD broadcasting by terrestrial channels, and also can receive up to 8K UHD additional communication networks. However, in order to transmit the 4K UHD contents within the allocated bit rate of the domestic terrestrial UHD broadcasting, the compression rate is increased, so a certain level of image deterioration occurs inevitably. Due to the nature of UHD contents, video quality should be considered as a top priority over other factors, so that video quality should be guaranteed even within a limited bit rate. This requires packet scheduling of content generators in the broadcasting system. Since the multiplexer sends out the packets received from the content generator in order, it is very important to make the transmission time and the transmission rate of the process from the content generator to the multiplexer constant and accurate. Therefore, we propose a variable transmission scheduler between the content generator and the multiplexer to guarantee the image quality of a certain level of UHD contents in this paper.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.444-451
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• 2022

Recently, long-term cultivation is becoming more common with the increase in tomato hydroponics. In hydroponics, it is very important to supply an appropriate nutrient solution considering the nutrient and moisture requirements of crops, in terms of productivity, resource use, and environmental conservation. Since seasonal environmental changes appear severely in long-term cultivation, it is so critical to manage irrigation control considering these changes. Therefore, this study was carried out to investigate the effect of irrigation volume on growth and yield in tomato long-term cultivation using coir substrate. The irrigation volume was adjusted at 4 levels (high, medium high, medium low and low) by different irrigation frequency. Irrigation scheduling (frequency) was controlled based on solar radiation which measured by radiation sensor installed outside the greenhouse and performed whenever accumulated solar radiation energy reached set value. Set value of integrated solar radiation was changed by the growing season. The results revealed that the higher irrigation volume caused the higher drainage rate, which could prevent the EC of drainage from rising excessively. As the cultivation period elapsed, the EC of the drainage increased. And the lower irrigation volume supplied, the more the increase in EC of the drainage. Plant length was shorter in the low irrigation volume treatment compared to the other treatments. But irrigation volume did not affect the number of nodes and fruit clusters. The number of fruit settings was not significantly affected by the irrigation volume in general, but high irrigation volume significantly decreased fruit setting and yield of the 12-15th cluster developed during low temperature period. Blossom-end rot occurred early with a high incidence rate in the low irrigation volume treatment group. The highest weight fruits was obtained from the high irrigation treatment group, while the medium high treatment group had the highest total yield. As a result of the experiment, it could be confirmed the effect of irrigation amount on the nutrient and moisture stabilization in the root zone and yield, in addition to the importance of proper irrigation control when cultivating tomato plants hydroponically using coir substrate. Therefore, it is necessary to continue the research on this topic, as it is judged that the precise irrigation control algorithm based on root zone-information applied to the integrated environmental control system, will contribute to the improvement of crop productivity as well as the development of hydroponics control techniques.

• The Korean Journal of Air & Space Law and Policy
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• v.27 no.1
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• pp.29-73
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• 2012

Aviation safety is the State and industry's top priority and more scientific approaches for fatigue management should be needed. There are lately various studies and regulation changes for crew fatigue management with ICAO, FAA and EASA. ICAO issued the provisions of fatigue management for flight crew since 1st edition, 1969, of Annex 6 operation of aircraft as a Standards and Recommended practice(SARPs). Unfortunately, there have been few changes and improvement to fatigue management provisions since the time they were first introduced. However the SARPs have been big changed lately. ICAO published guidance materials for development of prescriptive fatigue regulations through amendment 33A of Annex 6 Part 1 as applicable November 19th 2009. And then ICAO introduced additional amendment for using Fatigue Risk Management System (FRMS) with $35^{th}$ amendment in 2011. According to the Annex 6, the State of the operator shall establish a) regulations for flight time, flight duty period, duty period and rest period limitations and b) FRMS regulations. The Operator shall implement one of following 3 provisions a) flight time, flight duty period, duty period and rest period limitations within the prescriptive fatigue management regulations established by the State of the Operator; or b) a FRMS; or c) a combination of a) and b). U.S. FAA recently published several kinds of Advisory Circular about flightcrew fatigue. U.S. passed "Airline Safety and FAA Extension Act of 2010" into law on August 1st, 2010. This mandates all commercial air carriers to develop a FAA-acceptable Fatigue Risk Management Plan(FRMP) by October 31st, 2010. Also, on May 16, 2012, the FAA published a final rule(correction) entitled 'Flightcrew Member Duty and Rest Requirements; correction to amend its existing prescriptive regulations. The new requirements are required to implement same regulations for domestic, flag and supplemental operations from January 4, 2014. EASA introduced a Notice of Proposed Amendment (NPA) 2010-14 entitled "Draft opinion of the European Aviation Safety Agency for a Commission Regulation establishing the implementing rules on Flight and Duty Time Limitations and Rest Requirements for Commercial Air Transport with aeroplanes" on December 10, 2010. The purpose of this NPA is to develop and implement fatigue management for commercial air transport operations. Comparing with Korean and foreign regulations regarding fatigue management, the provisions of ICAO, FAA, EASA are more considering various fatigue factors and conditions. Korea regulations should be needed for some development of insufficiency points. In this thesis, I present the results of the comparative study between domestic and foreign regulations in respect of fatigue management crew member. Also, I suggest legal proposals for amendment of Korea Aviation act and Enforcement Regulations concerning fatigue management for crew members. I hope that this paper is helpful to change korea fatigue regulations, to enhance aviation safety, and to reduce the number of accidents relating to fatigue. Fatigue should be managed at all level such as regulators, experts, operators and pilots. Authority should change surveillance mind-set from regulatory auditor to expert adviser. Operators should identify various fatigue factors and consider to crew scheduling them. Crews should strongly manage both individual and duty-oriented fatigue issues.

• Journal of Korean Academy of Nursing
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• v.8 no.1
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• pp.16-42
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• 1978

This survey was made for a month starting from November 15 to December 15, 1977 covering 711 students taking the junior. (3rd-yea.) and the senior. (4th-year) at nine college of nursing in Seoul concerning their perception and Attitude toward the profession of nursing, motive for the necessity of learning, environment of study, attitude of study and particulars relevant with study performance, particulars of library, references and reading, assignments and particulars of the degree of confidence for the learning achievement. Through the survey of the above Particulars, the following results were obtained by classifying all subject matters and by analysing motive of the selection of their course, awarding or not awarding of scholarships. 1. General characteristics: it was revealed that 406 students (57.1%) were attending at the junior. while 305 students (42.9%) were taking the senior. Thus, the total number was 711 and their average age was 21.4 years. Their dwelling category was; 73.9 percent of them resided at their parent's home, 214 students (30.1%) were awarded with scholarships. The reason to be attracted by nursing science was the possibility of continuing social life after graduation (43.5%). 2. Their perception and attitude toward the profession of nursing: According to the perception of profession by the students of each grade, students of the 4th grade showed comparatively strong conception. Also, students of the 4th grade showed more positive attitude in the purchase and reading of magazines relative with the science of nursing, in the reading of Code for Nurses and in their interest in the activity of nursing field. For the necessity of mission of nurse, 97.7 percent of the entire number of students covered responded to necessity. For the necessity of the particular humanity and particularity in the character of nurses, 95.8 percent of those students responded to necessity. By the each grade, students of the 4th grade showed more response. 3. As to professional field desired after completing the professional course: 57 percent of those students desired for clinician nurse while 55 percents desired for community health-nurse. 4. As to the environment of study: they were mostly satisfied with their present residential environment. However, they complained of inconvenience at their lecture-halls. Students of the 3rd grade showed more complain. As to their attitude toward the adjustment of environment of study, they showed a affirmative response. As to the opinion of factors which interfere with their study, comparatively strong response was showed in their scepticism in the science of nursing, insufficient comprehension in general learning, relation with professors n4 discrepancy in the method of study. According to opinions of students at each grade, students of the 4th grade showed more scepticism. 5. Particulars relative with their attitude and performance of study : As to their knowledge of the objectives of their study of subject, the majority was to study with a partial knowledge of the objectives of their study. As to the plan of study, a low percentage indicated management of routine life under regular scheduling. Students of the 4th grade responded to rather planned life. As to time spent in independent study, response to concentrated study when necessary was stronger than that to regular daily study. Students of the 4th grade showed stronger response to regular study than that of the 3rd grade. As to the contents of their note-taking, 67.4 percents of those students responded to such regulatory procedure performing in the lecture-hall as they listen to lectures. 17.3 percents of those students showed response to adding supplementary informations from references to what was entered in choir note-taking at their lecture-halls. 6. Particulars of library, references and reading books: As to receiving of instruction for the utilization of library and time of receiving such instruction 64.7 percents of those students had received such instruction. 66.7 percents of the those responded received such instruction at orientation conducted for freshmen. As to the convenience of the utilization of library, 49.9 percents of those students responded to convenience. However, students of the 3rd grade showed a much stronger response to inconvenience. As to the time of the utilization of library,92.5 percents of those students showed a response to occasional utilization for particular purpose than regular utilization. 53.2 percents of those students responded to ordinary in quantity that library have references. 34.2 percents of those students responded to insufficient. As to the particular relative with the method and field of reading: 53.5 percents of those students responded to intensive reading and was the majority. As to the reading field, fiction u as the majority. When read any books for their major, they usually rend Korean text-b, oks. 7. Particular relative with giving assignment: All respondents were well aware of the objectives of giving home tasks. As to the attitude toward assignments and performing home tasks, 54.8 percents of those students to making ostentatious study because of an excessive quantity of assignments imposed. For performing assignment, they showed comparatively positive response. Also, 52.2 percents of those students responded that they usually submitted complected assignment with references. 8. As to motive to realize the necessity of study : 55.6 percents of those students responded that they realized such necessity in communication with patients when they were engaged in clinical practice. Also, 8.6, the lowest percents of those students responded that they realized such necessity in the course of conversation with nurses when they were engaged in clinical practice. 9. As to the determination of their confidence in the performance of study relative with clinical experience: They showed a general inclination of having in nursing. The major response was that they came to well comprehend the patients families. the lowest response was that they could apply what was learned at lecture-hall to practice. This response incidentally showed the distance the lecture-hall and practical study. In general items, students of the 4th grade showed more favorable response than students of the 3rd grade and there was a significant difference. 10. As to the perception and attitude toward profession according to the motive of selecting the nursing science : Those who selected the nursing voluntarily showed stronger conception than those who selected the nursing through indirect influence. However, there was no significant difference on this point. Only there was a remarkable difference in the reading of Code for Nurses. 11. Those who showed a stronger conception in the profession of nursing according to the motives of attractive nursing science indicated a strong will and ability to manage stable life and comparatively strong response was shown in the management of good home life because of the good adaptability of the science to their character. This group showed a strong conception of the profession than those who responded that they prefer this profession out of a longing for the work of a hospital and for the easy obtaining of opportunity to immigrate to over seas and for economic cause and for high school grade. There was significant difference between these two groups, 12. As to the conception and attitude toward the profession of nursing according to benefits by scholarships, those who were benefitted by scholarship showed stronger conception of profession than those who did not receive scholarship and there was a remarkable difference between these two categories. However, there was no remarkable difference between these two categories in the extent of interest of the activities of nursing fields and in the reading of Code for Nurses. 13. As activation for study according to the benefits of scholarships, those who were benefitted by scholarships showed stronger response to the motive for study comparing with those who receive. 14. As to tile field of reading according to the benefits by scholarships, those who received scholarships tended to read autobiographies and essayers to a considerable extent. Those who did not receive scholarships tended to read novels. Those who received scholarships more read nursing boots than those who did not receive scholarships. 15. As to the attitude of study and doing of assignment according to benefits of scholarships, those who received scholarships managed a favorable life with schedules for study, More students of receiving scholarship showed a regular study for more than one hour per day. Also, in the method of doing home tasks, more students of receiving scholarship showed reference to relative books frequently for the submission of completed assignments.