• Macromolecular Research
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• v.17 no.8
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• pp.616-622
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• 2009

In-depth understanding of the influence of hot pressing and melt processing on the properties of thermoplastic polyurethane (TPU) is critical for effective mechanical recycling of TPU scraps. Therefore, this study focused on the effects of hot pressing and melt mixing on molecular weight (MW), polydispersity index (PDI), melt index (MI), characteristic IR peaks, hardness, thermal degradation and mechanical properties of TPU. The original TPU pellet (o-TPU) showed two broad peaks at lower and higher MW regions. However, four TPU film samples, TPU-0 prepared only by hot pressing of o-TPU pellet and TPU-1, TPU-2 and TPU-3 obtained by hot pressing of melt mixed TPUs (where the numbers indicate the run number of melt mixing), exhibited only a single peak at higher MW region. The TPU-0 film sample had the highest $M_n$ and the lowest PDI and hardness. The TPU-1 film sample had the highest $M_w$ and tensile modulus. As the run number of melt mixing increased, the peak-intensity of hydrogen bonded C=O stretching increased, however, the free C=O peak intensity, tensile strength/elongation at break and average MW decreased. All the samples showed two stage degradations. The degradation temperatures of TPU-0 sample (359 $^{\circ}C$ and 394 $^{\circ}C$)were higher than those of o-TPU (342 $^{\circ}C$ and 391 $^{\circ}C$). While all the melt mixed samples degraded at almost the same temperature (365 $^{\circ}C$ and 381 $^{\circ}C$). The first round of hot pressing and melt mixing was found to be the critical condition which led to the significant changes of $M_n$/$M_w$/PDI, MI, mechanical property and thermal degradation of TPU.

• Journal of Sericultural and Entomological Science
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• v.14 no.2
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• pp.95-103
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• 1972

The major purpose of this study is to collect the information related on the aspects of economic efficiency for solving the problems which are faced by farmers and areas, and providing scientific facts to farmers and related institutions for further development of sericultural sector in Korea. In order for obtaining the related information 12 sample areas among 23 major sericultural farming areas and 30 farm units in each area are selected and analyzed in this study. The fold suevey is made by member of this study team and graduate students in the Department of Sericultural Science with a prepared questionnaires. Cross-section and regression analysis methods are employed for processing the data in this study. The major findings obtained are as followings. 1. Sericultural earnings per Tanbo is, on the average, 22, 752 won in new cultivated areas and 29, 403 won in ordinary ones. There are big difference in the size of earnings by areas, especially, 46, 968 won in Kumo mountain area, compared with 16, 798 won in Yeoju and Yichun areas. General trend is finded that small scale farming units are made higher earnings and operating their farms efficiently. 2. Cocoon production expences per Tanbo is 16, 737 won in new cultivated areas and 19, 802 won in ordinary areas. There are also big difference in farming expences, especially, 27, 389 won in Sudang area, compared with 11, 689 won in Emjin area. 3. Sericultural income per Tanto is 10, 664 won in ordinary areas and 6, 898 won in new cultivated areas. Farmers in Kumo mountain area make the highest income of 21, 164 won and lowest income of 1, 296 won in Sudang area. It can be generized that about 30-50 a sized farmers make higher income. 4. Land, labor and capital productivities estimated by fitting Cobb-Douglas functions in ordinary areas are higher than in new cultivated areas, especially, labor productivity is higher in ordinary areas. 5. Changsung, Kwangna, Yunsun and Kumo mountain areas are technically and economically efficient. Sudang and Mujinchang areas are technically successful but economically inefficient and Emjin and Honam areas are technically inefficient but economically efficient. YeojuYichun, Chunwon and West Kyongnam are technically and economically inefficient. Technical and economic improvement program should be implemented for these areas. 6. Estimated Internal Rate of Return (IRR) on capital investment in Chongwon are is 23.5 percent. It is economically feasible, if we consider 20 percent of opportunity cost of capital in our economy.

• The Korean Nurse
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• v.37 no.2
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• pp.44-52
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• 1998

The purpose of this study is to inquire the people's views on nursing for nurses, correct the image of nurse and take it as basis to be applied on nursing education examining the image of nursing on Television drama playing important role of mass media. 22 nurses of the characters in drama is applied to the analysis object of this study by selecting 6 dramas of Television ones the nurse play on the prime time from June 1 to August 31 in 1997. Contents analysis method was used in Data Analysis, 4 items was used after Coders previously modify and compensate it based on research documents of 1m Milim(1996) 2 Coders made the Coding the article on each person by them seeing the recorded film making the Coding Paper each items is written by the character. The average of reliability degree was 90% which measured the reliability degree by the mathod of Holsti. The statisic method of frequency, percentage was used SPSS Program in data processing The results were as follows. 1. Relative importance of 86.2% nurses in drama was depicted as extra characters 2. The affair attitude of nurses shown on drama was revealed as mechanical(84.7%), passive(45.5%), dependent(54.4%) unkind(68.2%). 3. The activity of nurses was classified with professional! simple affair. The professional affairs such as I.V., Blood Pressure Check, Rounding, Nursing Recording, Patient Education, Assist of Operation, Assistant meal of Patient, etc is mainly depicted and the screen of simple affair such as Receiving telephone, Carrying Tray or Dragging, Stretcher Car, Dressing Car and or Wheel Chair than professional affair. 4. The appearance feature of nurses was shown on thin physique(68.2%), common stature(68.2), dirty costume(45.4%), common appearance(81.9%), unnoble action(63.6%). The image of nurses is illuminated as the exterial scene of technical affair such as assisting the doctors and affair focused on accident and educational activity of nureses or extended role is nor depicted on Television drama. Therefore, the people regard the nurse as sexual object with good appearance than professional worker working professional nursing We want the following, epigraph based on above conclusion. 1. The continuous research is required on the image of nurse shown on various mass media. 2. The later research is required on appliction strategy of mass media for advancing the image of nurse. 3. The research to strengthen the objectivity by comparing analyzed data on drama & analyzing it is required 4. Through the deep study, the standard to show a concrete and professional work of nurses to scenario writers of TV drama is suggested by the association. 5. The monitoring about the mass media must be activated, not by some nurses, on a national scale and much study on the basis of this is needed.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.10
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• pp.383-392
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• 2014

The research for coatings is one of the most popular and active research in the polymer industry. For the coatings, electronics industry, medical and optical fields are growing more important. In particular, the trend is the increasing of the technical requirements for the performance and accuracy of the coatings by the development of automotive and electronic parts. In addition, the industry has a need of more intelligent and automated system in the industry is increasing by introduction of the IoT and big data analysis based on the environmental information and the context information. In this paper, we propose an optimization model for the design of experiments based coating formulation data objects using the Internet technologies and big data analytics. In this paper, the coating formulation was calculated based on the best data analysis is based on the experimental design, modify the operator with respect to the error caused based on the coating formulation used in the actual production site data and the corrected result data. Further optimization model to correct the reference value by leveraging big data analysis and Internet of things technology only existing coating formulation is applied as the reference data using a manufacturing environment and context information retrieval in color and quality, the most important factor in maintaining and was derived. Based on data obtained from an experiment and analysis is improving the accuracy of the combination data and making it possible to give a LOT shorter working hours per data. Also the data shortens the production time due to the reduction in the delivery time per treatment and It can contribute to cost reduction or the like defect rate reduced. Further, it is possible to obtain a standard data in the manufacturing process for the various models.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.9
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• pp.211-216
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• 2016

Worldwide casualties caused by earthquakes, floods, fire or other disaster has been increasing. So many researchers are being actively done technical studies to ensure golden-time. In this paper if a disaster occurs, use the IoT technologies in order to secure golden-time and transmits the message after to find the user of the accident area first. When the previous job is finished, gradually finds a user of the surrounding area and transmits the message. For national emergency information, OPEN API of Korea Meteorological Administration was used. To collect detailed information on a relevant area in real time, this study established the system that connects and integrates Crowd Sensing technology with BLE (Bluetooth Low Energy) Beacon technology. Up to now, the CBS based on base station has been applied. However, this study designed and mapped DB in the integration of Beacon based user positioning and national administrative address system in order to estimate local users. In this experiment, the accuracy and speed of information dif6fusion algorithm were measured with a rise in the number of users. The experiments were conducted in a manner that increases the number of users by one thousand and was measured the accuracy and speed of the message spread transfer algorithm. Finally, became operational in less than one second in 20,000 users, it was confirmed that the notification message is sent.

• Resources Recycling
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• v.28 no.5
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• pp.3-18
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• 2019

Due to the increasing demand for clean energy, the consumption of lithium ion batteries (LIBs) is expected to grow steadily. Therefore, stable supply of lithium is becoming an important issue globally. Commercially, most of lithium is produced from the brine and minerals viz., spodumene, although various processes/technologies have been developed to recover lithium from other resources such as low grade ores, clays, seawaters and waste lithium ion batteries. In particular, commercialization of such recycling technologies for end-of-life LIBs being generated from various sources including mobile phones and electric vehicles(EVs), has a great potential. This review presents the commercial processes and also the emerging technologies for exploiting minerals and brines, besides that of newly developed lithium-recovery-processes for the waste LIBs. In addition, the future lithium-supply is discussed from the technical point of view. Amongst the emerging processes being developed for lithium recovery from low-grade ores, focus is mostly on the pyro-cum-hydrometallurgical based approaches, though only a few of such approaches have matured. Because of low recycling rate (<1%) of lithium globally compared to the consumption of lithium ion batteries (56% of lithium produced currently), processing of secondary resources could be foresighted as the grand opportunity. Considering the carbon economy, environment, and energy concerns, the hydrometallurgical process may potentially resolve the issue.

• Journal of the Korea Society of Computer and Information
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• v.24 no.11
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• pp.127-133
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• 2019

SQL is the most common language in data processing. Therefore, most of the colleges offer SQL in their curriculum. In this research, an auto scoring SQL test is proposed for the efficient results of SQL education. The system was treated with algorithms instead of using expensive DBMS(Data Base Management System) for automatic scoring, and satisfactory results were produced. For this system, the test question bank was established out of 'personnel management' and 'academic management'. It provides users with different sets of test each time. Scoring was done by dividing tables into two sections. The one that does not change the table(select) and the other that actually changes the table(update, insert, delete). In the case of a search, the answer and response were executed at first and then the results were compared and processed, the user's answers are evaluated by comparing the table with the correct answer. Modification, insertion, and deletion of table actually changes the data table, so data was restored by using ROLLBACK command. This system was implemented and tested 772 times on the 88 students in Computer Information Division of our college. The results of the implementation show that the average scoring time for a test consisting of 10 questions is 0.052 seconds, and the performance of this system is distinguished considering that multiple responses cannot be processed at the same time by a human grader, we want to develop a problem system that takes into account the difficulty of the problem into account near future.

• Journal of Convergence for Information Technology
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• v.11 no.11
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• pp.143-150
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• 2021

It introduces the contents of establishing a geostationary satellite-based forest fire monitoring system that can monitor areas of the Korean Peninsula 24 hours a day for forest fire monitoring, and describes how to establish a forest fire monitoring system and use it in various ways. In order to establish a satellite-utilized forest fire monitoring system, we will describe and draw conclusions on literature research, technical principles, forest fire monitoring means, and satellite forest fire monitoring system. The satellite-utilized forest fire monitoring system can consist of one geostationary satellite equipped with infrared detection optical sensors and a ground processing station that processes data received from satellites to spread surveillance information. Forest fire monitoring satellites are located in the country's geostationary orbit and should be operated 24 hours a day, 365 days a day. Forest fire monitoring technology is an infrared detection technology that can be used in national public interests such as forest fire monitoring and national security. It should be operated 24 hours a day, and to satisfy this, it is efficient to establish a geostationary satellite-based forest fire monitoring satellite system.

• Journal of Practical Engineering Education
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• v.13 no.2
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• pp.327-332
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• 2021

Materials used for education include SM20C, Al6061, and acrylic. SM20C materials are used a lot in certification tests and functional competitions as carbon steel, but they are also used in industrial sites. Al6061 is said to be a material that produces a lot of tools because it has lower hardness than carbon steel and is highly flexible. When practical guidance is given to students using acrylic materials, it is a material that causes vibration and tool damage due to excessive cutting. In this process, we examine how impact on the 5-axis equipment 2NC head can affect precision control. The weakest part of a five-axis equipment is the head that controls the AC axis. In the event of precision and cumulative tolerances in this area, the precision of all products is reduced. Thus, a key part of the 2NC head, the spindle housing was carried out using Al7075 T6 (U.S. Alcoasa) material and the entire body using FCD450 (spherical graphite cast iron). In the vibration and cutting process acting on these two materials, the analysis was carried out to determine the value of applying the force as a finite element analysis under extreme conditions. We hope that using these analytical data will help students see and understand the structure of 5-axis machining rather than 5-axis cutting.

• Journal of Conservation Science
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• v.34 no.6
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• pp.493-502
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• 2018

Currently, the fabrication of a high-tin bronze spoon by traditional manufacturing techniques involves 10 steps in the bronze ware workshop. Hot forging has a major influence on manufacturing and involves two to three steps. The dendritic ${\alpha}$-phase in the microstructure of the high-tin bronze spoon is refined and finely dispersed through hot forging. In addition, twinning is observed in the ${\alpha}$-phase of the hammered part, and the ${\alpha}$-phase microstructure gradually transform from a polygon to a circular shape due to hammering. In this process, the adjacent ${\alpha}$-phases overlap with each other and remain combined after quenching. The microstructure with the overlapping is also observed in bronze artifacts, and this shows the correlation with technical system. The results of the experimental hot forging of Cu-22%Sn alloys show that the decrease in in the amount of the dendritic microstructure, which forms during casting, is in proportion to the number of processing steps and that the refined grain obtained by hammering contributes to the improvement in the strength of the material. From the hammering marks, which are observed on both the bronze artifact excavated from archaeological sites and on the high-tin bronze spoon produced in the traditional workshop, it is presumed that the knowledge regarding the unrecorded manufacturing system of bronze ware in ancient times has been passed down in a traditional way up to the system used currently.