• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.6-7
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• 2020

The unit-water content of concrete is one of the important factors in determining the quality of concrete and is directly related to the durability of the construction structure, and the current method of measuring the unit-water content of concrete is applied by the Air Meta Act and the Electrostatic Capacity Act. However, there are complex and time-consuming problems with measurement methods. Therefore, high frequency moisture sensor was used for quick and high measurement, and unit-water content of mortar was evaluated through machine running and deep running based on measurement big data.

• Animal Bioscience
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• v.37 no.2_spc
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• pp.385-395
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• 2024

Ruminal ciliates are a fundamental constituent within the rumen microbiome of ruminant animals. The complex interactions between ruminal ciliates and other microbial guilds within the rumen ecosystems are of paramount importance for facilitating the digestion and fermentation processes of ingested feed components. This review underscores the significance of ruminal ciliates by exploring their impact on key factors, such as methane production, nitrogen utilization efficiency, feed efficiency, and other animal performance measurements. Various methods are employed in the study of ruminal ciliates including culture techniques and molecular approaches. This review highlights the pressing need for further investigations to discern the distinct roles of various ciliate species, particularly relating to methane mitigation and the enhancement of nitrogen utilization efficiency. The promotion of establishing robust reference databases tailored specifically to ruminal ciliates is encouraged, alongside the utilization of genomics and transcriptomics that can highlight their functional contributions to the rumen microbiome. Collectively, the progressive advancement in knowledge concerning ruminal ciliates and their inherent biological significance will be helpful in the pursuit of optimizing rumen functionality and refining animal production outcomes.

• Current Optics and Photonics
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• v.8 no.4
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• pp.327-344
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• 2024

Optical phantoms are essential in optical imaging and measurement instruments for performance evaluation, calibration, and quality control. They enable precise measurement of image resolution, accuracy, sensitivity, and contrast, which are crucial for both research and clinical diagnostics. This paper reviews the recent advancements and challenges in phantoms for optical coherence tomography, photoacoustic imaging, digital holographic microscopy, optical diffraction tomography, and oximetry tools. We explore the fundamental principles of each technology, the key factors in phantom development, and the evaluation criteria. Additionally, we discuss the application of phantoms used for enhancing optical-image quality. This investigation includes the development of realistic biological and clinical tissue-mimicking phantoms, emphasizing their role in improving the accuracy and reliability of optical imaging and measurement instruments in biomedical and clinical research.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.139.2-139.2
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• 2016

Electrons and phonons in chalcogenide-based materials play are important factors in the performance of an optical data storage media and thermoelectric devices. However, the fundamental kinetics of carriers in chalcogenide materials remains controversial, and active debate continues over the mechanism responsible for carrier relaxation. In this study, we investigated ultrafast carrier dynamics in an multilayered $\{Sb(3{\AA})/Te(9{\AA})\}n$ thin film during the transition from the amorphous to the crystalline phase using optical pump terahertz probe spectroscopy (OPTP), which permits the relationship between structural phase transition and optical property transitions to be examined. Using THz-TDS, we demonstrated that optical conductance and carrier concentration change as a function of annealing temperature with a contact-free optical technique. Moreover, we observed that the topological surface state (TSS) affects the degree of enhancement of carrier lifetime, which is closely related to the degree of spin-orbit coupling (SOC). The combination of an optical technique and a proposed carrier relaxation mechanism provides a powerful tool for monitoring TSS and SOC. Consequently, the response of the amorphous phase is dominated by an electron-phonon coupling effect, while that of the crystalline structure is controlled by a Dirac surface state and SOC effects. These results are important for understanding the fundamental physics of phase change materials and for optimizing and designing materials with better performance in optoelectronic devices.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.2
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• pp.149-160
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• 2008

Bag-filter system has been widely used in industrial field to remove the particulate matters from the exhaust gas. The cylindrical type of bag-filter has been generally used. But it has many shortcomings. The reattachment of separated particles on the surface of bags could result in high pressure drop of bag-filter system and subsequent decrease of air flow rate since the cylindrical type bag-filter system should have the upward flow pattern. In addition, the supply of very high pressure pulse air jet to remove particulate matters on the surface of filter could result in a frequent rupture of bags. To overcome these shortcomings of the cylindrical type, the rectangular type was developed in the developed countries and imported to Korea. But, there was not many design data available to understand the mechanisms. Thus, the fundamental experiments were conducted in this study to get some ideas about the pulse jet cleaning of rectangular type bag filter system. The experimental factors are as follows; pulse distance, pulse duration, pulse interval, pulse pressure and pulse nozzle type. Experiments followed the factorial design method. With the shorter pulse distance, the distribution of pressure drops was relatively not uniform while the particulate removal efficiency was higher. With the longer duration of pulsing and the more number of pulse nozzle, the removal efficiency was higher and the pressure drop distribution was more uniform.

• Journal of Yeungnam Medical Science
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• v.16 no.1
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• pp.10-14
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• 1999

The World Association for Sexology (WAS) will adopt a Declaration of Sexual Rights as basic and fundamental human rights August this year in Hong Kong. Two years ago WAS has been developing a Declaration of Sexual Rights in order to further promote sexual health and protect the sexual rights of everyone. Undoubtedly sexuality is one of the most intriguing subjects in the area of human behavior and psychology, and has been so since antiquity. The influence of sexual factors of human on all aspects of the society has been immense. The varieties of marriage, from traditional to the open marriage model are presented in front of our sight. The influences of women's movement in Korea, which has produced sexual, psychological, economic, political, familial and social changes look so small and the changes are not that much in America. But the profound effects of the women's movement affect on Korean society being realized as man's view of woman and woman's view of herself undergo constant change and reevaluation. With increased sexual awareness on the part of the public owing to mass media, for example AH-U-SEONG aired in TV and with increased emphasis on sexual matters in daily life, more and more physicians are being asked to deal with and manage sex-related problems in their daily practice. Yet, despite the obvious need for informed sexual counseling, doctors are often uncomfortable about sexual matters and many physicians have no special expertise in this area. So physicians concerned in sexology especially such as gynecologists, urologists, psychiatrists and endocrinologists must realize well about sex-related knowledge which is needed for counseling the patient as medical consumer and gap between reality and ideality in sexual diagnosis and treatment. Establishment of management system for the people who have sexual problems is strongly needed to promote sexual health and protect the sexual rights of everyone and for the Sexual Rights as basic and fundamental human rights.

• The Journal of the Korea Contents Association
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• v.10 no.6
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• pp.373-377
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• 2010

Numerous quantitative and qualitative studies have already been published related to English vowels. However, only minimal amounts of studies based on the acoustic analysis of Korean vowels have been accomplished. The purpose of this study is to obtain sufficient quantitative data based on the acoustic aspects of Korean vowels produced by males between the ages of 20s and 30s. A total of 31 males in their 20s and 30s produced the five fundamental vowels /a, e, i, o, u/ by repeating each of them three times in the standard Korean dialect. Such speech productions were recorded with 'Cool edit' and F1, F2, F3, F4 were extracted through the MATLAB acoustic analysis program. Results indicated that the overall patterns of formants were similar to previous studies, except that the formant levels of F1 and F2 of the vowels produced in this study were generally lower than that in previous studies. Future studies need to focus on obtaining vowel data by considering other factors such as age and other speech materials.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1643-1646
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• 2003

Drawing is a mechanical operation that attenuates thick material to an appropriate thickness for the next processing or end usage. When the input material has the form of a bundle or bundles made of very thin and long shaped wire or fibers, this attenuation operation is called "bundle drawing" or "drafting" Drafting is being used widely in manufacturing staple yarns. which is indispensable for the textile industry. However, the bundle processed by this operation undertake more or less defects in the evenness of linear density. Such irregularities cause many problems not only for the product quality but also for the efficiency of the next successive processes. Since long there have been many researches tying to find out factors affecting the irregularity of linear desity, to obtain optimal drafting conditions, to develop efficient measuring and analysis methods of linear density of bundle, etc., but there exists yet no fundamental equation describing the dynamic behavior of the flowing bundle during processing. In this research a mathematical model for the dynamic behavior of the bundle fluid is to be set up on the basis of general physical lows representing physical variables, i.e. linear density and velocity as the dynamic state of bundle. The conservation of mass and momentum balance was applied to the fluid field of bundle. while the movement of′ individual material was taken into account. The constitutive model relating the surface force and the deformation of bundle was introduced by considering a representative prodedure that stands for the bundle movement. Then a fundamental equations system could be simplified considering a steady state of the process. On the basis of the simplified model, the simulation was performed and the results could be confirmed by the experiments under various conditions.

• School Mathematics
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• v.12 no.3
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• pp.371-388
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• 2010

The goals of this study are to inquire middle school students' understanding about prime number and to propose pedagogical implications for school mathematics. Written questionnaire were given to 198 Korean seventh graders who had just finished learning about prime number and prime factorization and then 20 students participated in individual interviews for member checks. In defining prime and composite numbers, the students focused on distinguishing one from another by numbering of factors of agiven natural number. However, they hardly recognize the mathematical connection between prime and composite numbers related on the multiplicative structure of natural number. This study suggests that it is needed to emphasize the conceptual relationship between divisibility and prime decomposition and the prime numbers as the multiplicative building blocks of natural numbers based on the Fundamental Theorem of Arithmetic.

• Journal of Korea Technology Innovation Society
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• v.15 no.2
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• pp.400-420
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• 2012

This study explores the way to enhance research performance focusing basic and fundamental technology when researchers conduct international joint research with counterparts in foreign countries, funded under the National R&D programs. In order to retain validity and objectivity, mixed approaches including qualitative and quantitative are adapted at the first step. Through this step, main factors affecting the research performance can be addressed, such as the number of SCI papers published, conference attendance held both in domestic and foreign countries, researchers holding PhD involving in projects. Then, at the second step, DEA methodology is applied to explore the way to enhance research performance, based on the analysis at first step. The result at second step shows that the various ways can be drawn according to programs respectively and the general assumption of research funds and number of projects affecting positive outcome is not absolutely mentioned. Therefore, this study implies that input variables including research funds are not compatible with research performance in terms of international joint research and suggests further that the decisive outcome and management be reconsidered according to the programs respectively under the national R&D program.