• Journal of the Korean Society of Safety
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• v.39 no.2
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• pp.1-8
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• 2024

Unwanted effects of electrostatic phenomena occur in various industries. Electrostatic problems originating from the human body in flammable atmospheres in the industry are especially concerning. A substantial volume of experimental data on the electrostatic charging voltages created on the human body owing to the rubbing of apparel were generated and reviewed during this study. The data were reviewed to determine whether the resultant charging levels of the human body are hazardous in flammable atmospheres. This study was conducted under several conditions, such as different fiber types used in apparel, shoe types, and relative humidities (RHs). The following conclusions were drawn in this study. ① The electrostatic charging levels of the human body owing to the rubbing of apparel increase with the increase in the surface resistances of apparel; however, the electrostatic charging levels may be different depending on the condition of the cloth surface. ② The discharging energy of 1.98-18.5 [mJ] from the human body exceeds the minimum ignition energy of most flammable materials, when removing an overcoat made of polyester, cotton and wool under severe conditions such as wearing height-raising shoes for men. ③ When removing antistatic apparel, the maximum discharging energy of 0.128 mJ from the human body is dangerous if the minimum ignition energy of the flammable material is between 10^-5-10^-4 [J] Grade; however, a minimum ignition energy of 10^-3 J Grade of the flammable material is considered safe. ④ While wearing antistatic shoes, the electrostatic charging voltage generated in the human body when removing an overcoat is 30 V; therefore, wearing such shoes is a suitable countermeasure when handling flammable materials. However, the antistatic abilities of shoes reduce when thick socks are worn. ⑤ As RH increases, the electrostatic charging levels of the human body decrease. ⑥ The electrostatic charging levels of the human body from removing a cotton overcoat can ignite the majority of flammable materials when RH is less than 30% under severe conditions such as wearing height-raising shoes for men.

• Proceedings of the Korean Society of Life Science Conference
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• 2005.09a
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• pp.93-93
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• 2005

• Journal of the Society of Disaster Information
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• v.15 no.1
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• pp.121-132
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• 2019

Purpose: This study aims to analyze the meaning of architectural space of Alvar Aalto, which is based on architectural theories of periodic flows and the form of the space with the various elements applied to the works. Method: It analyzes the interrelationships of light, form and material in triangular composition by synthesizing the architectural vocabulary of Alvar Aalto from the viewpoint of modernism. Results: The architectural works of Alvar Aalto are centered on the combination of light, form, material, and space diversity, emphasizing social awareness and linking the human scale with the building environment. Conclusion: The structure of the Alvar Aalto is a synonym of nature and culture, society and individuals, standardization and diversity, universality and locality, intellectual and emotional, scientific and human psychological. It is possible to apply reciprocity elements to architectural spaces in a comprehensive manner while being different from each other in terms of rationality and immediacy.

• Journal of Korean Elementary Science Education
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• v.24 no.2
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• pp.160-173
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• 2005

In this study, we had tried to present a plan for improving the actual conditions of practical utilization of teaching material for 6th grade science developed by Ministry of Education & Human Resources Development and distributed to all elementary schools in Korea. Also we presented ways of better utilization of the teaching material after investigating the actual conditions of practical utilization. A survey was made to investigate and collect all data in the major metropolitan cities, the Kangwon, Chungcheong, Honam, and Kyeongsang area, respectively. We surveyed 316 6th grader teachers to investigate the actual conditions of distribution and utilization of teaching material as a general research. In addition, we surveyed 46 teachers to investigate the organization and content of teaching material as a particular research. The results are as follows. First, the teaching material was not approximately transmitted and kept to 6th grader teachers. Second, the utilization guide was not made. Third, it was reported that the thematic divisions of teaching material was a strong point, but the less detailed experiment manual was a weak point. Fourth, the consideration of content difficulties and simplicity was necessary to improve the material. Fifth, additional items should be included in the introductory presentation, convenience of reorganization, activity material causing learning interest, guidance of substitution experiment, and more concrete notice of experiment activity. Finally, there were positive responses of more than 4.0 point of Likert scale (1 to 5 point scale) in detail investigations of thematic items, which could have possibility that the teaching material was helpful to elementary school science field.

• Journal of the Korean Society of Costume
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• v.54 no.8
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• pp.147-162
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• 2004

The purpose of this study is to investigate the characteristics of Grotesque in Contemporary Fashion. The study selected the 1990's or after fashion material by the material of both $pr{\hat{e}}t-{\grave{a}}-porter$ collection and haute couture collection based on Europe. These days, the characteristics of grotesque have been categorized into four groups based on the theory of representative scholars of the Post Modernism era. The results are as follows. ${\cdot}$ The devilism creates shocking and destructive cruelty and fear by using frightening object and mysterious and devilish motif which symbolize the death of fashion ${\cdot}$ Hatred produces physical destroy of human body, anatomical expression inside human body, cruelty by naked sex expression, pains, cruel treatment, disillusion and unpleasantness, which have been caused by the disturbance and ideological confrontation of the society, and is said to be a kind of self-confession against dislike and fear of the disclosure of human existence. ${\cdot}$ Playfulness distorts and exaggerates clothes and human body forms, and produces abnormality and mystery because of vague sex identity. The playfulness of fashion can open fixed and closed world and lead it flexibly. ${\cdot}$ Heterogeneity is divided into both primitiveness and virtuality The primitiveness distorts or transforms human body through the human body decoration of primitive race, and expresses a grotesque form combining human being and other animals. It gives a question to the existence of alienated and suppressed life through the world. in which everything is mixed and not separated. The virtuality introduces not only cyborg form combining human being and machines but also state of the art technology factors, so that it emphasizes non-mechanical and non-human grotesque images.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.353-356
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• 2005

There have been many researches on the antenna performance degradation with the presence of the human body around the antenna structure to accomodate personal communication service [1][2]. To better understand the human body effects on the antenna resonance, radiation pattern, and input impedance, simulation was carried out with changing of the distance between antenna and lossy material. Effects on the antenna performance by the surrounding materials are also important in the case of the RFID system. It is desirable that the tag antennas for RFID system must reveal isotropic radiation pattern as well as attain the good impedance matching. In this paper, we investigated the antenna resonance and input impedance characteristic when there exist a lossy material sphere near various types of antenna at 900 MHz. In short antenna resonance was mostly affected by lossy material in the case of a rectangular loop antenna, and impedance variation was smallest in the case of a halfwave dipole.

• Journal of Intelligence and Information Systems
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• v.6 no.2
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• pp.29-40
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• 2000

Process planning (selection and ordering of processes) and material selection for product manufacturing are two key things determined before taking full-scale manufacturing. Knowledge on product design. material characteristics, processes, time and cost all-together are mutually related and should be considered concurrently. Due to the complexity of problem, human experts have got only one of the feasilbe solutions with their field knowledge and experiences. We propose a hierarchical expert system framework of knowledge representation and reasoning in order to overcome the complexity. Manufacturing processes have inherently hierarchical relationships, from top level processes to bottom level operation processes. Process plan of one level is posted in process blackboard and used for lower level process planning. Process information on blackboard is also used to adjust the process plan in order to resolve the dead-end or inconsistency situation during reasoning. Decision variables for process, material, tool, time and cost are represented as object frames, and their relationships are represented as constraints and rules. Constraints are for relationship among variables such as compatibility, numerical inequality etc. Rules are for causal relationships among variables to reflect human expert\`s knowledge such as process precedence. CRSP(Constraint and Rule Satisfaction Problem) approach is adopted in order to obtain solution to satisfy both constraints and rules. The trade-off procedure gives user chances to see the impact of change of important variables such as material, cost, time and helps to determine the preferred solution. We developed the prototype system using visual C++ MFC, UNIK, and UNlK-CRSP on PC.

• The Journal of Advanced Prosthodontics
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• v.2 no.1
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• pp.7-13
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• 2010

Although most researchers agree that platelet-rich plasma (PRP) is a good source of autogenous growth factors, its effect on bone regeneration is still controversial. The purpose of this study was to evaluate whether increasing angiogenic factors in the human PRP to enhance new bone formation through rapid angiogenesis. MATERIAL AND METHODS. In vitro, the human platelets were activated with application of shear stress, $20\;{\mu}g/ml$ collagen, 2 mM $CaCl_2$ and 10U thrombin/$1\;{\times}\;10^9$ platelets. Level of vascular endothelial growth factor (VEGF) and platelet microparticle (PMP) in the activated platelets were checked. In the animal study, human angiogenic factors-enriched PRP was tested in 28 athymic rat's cranial critical bone defects with $\beta$-TCP. Angiogenesis and osteogenesis were evaluated by laser Doppler perfusion imaging, histology, dual energy X-ray densinometry, and micro-computed tomography. RESULTS. In vitro, this human angiogenic factors-enriched PRP resulted in better cellular proliferation and osteogenic differentiation. In vivo, increasing angiogenic potential of the PRP showed significantly higher blood perfusion around the defect and enhanced new bone formation around acellular bone graft material. CONCLUSION. Angiogenic factor-enriched PRP leads to faster and more extensive new bone formation in the critical size bone defect. The results implicate that rapid angiogenesis in the initial healing period by PRP could be supposed as a way to overcome short term effect of the rapid angiogenesis.

• Archives of Craniofacial Surgery
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• v.16 no.1
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• pp.11-16
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• 2015

Background: Source material used to fill calvarial defects includes autologous bones and synthetic alternatives. While autologous bone is preferable to synthetic material, autologous reconstruction is not always feasible due to defect size, unacceptable donor-site morbidity, and other issues. Today, advanced three-dimensional (3D) printing techniques allow for fabrication of titanium implants customized to the exact need of individual patients with calvarial defects. In this report, we present three cases of calvarial reconstructions using 3D-printed porous titanium implants. Methods: From 2013 through 2014, three calvarial defects were repaired using custom-made 3D porous titanium implants. The defects were due either to traumatic subdural hematoma or to meningioma and were located in parieto-occipital, fronto-temporo-parietal, and parieto-temporal areas. The implants were prepared using individual 3D computed tomography (CT) data, Mimics software, and an electron beam melting machine. For each patient, several designs of the implant were evaluated against 3D-printed skull models. All three cases had a custom-made 3D porous titanium implant laid on the defect and rigid fixation was done with 8 mm screws. Results: The custom-made 3D implants fit each patient's skull defect precisely without any dead space. The operative site healed without any specific complications. Postoperative CTs revealed the implants to be in correct position. Conclusion: An autologous graft is not a feasible option in the reconstruction of large calvarial defects. Ideally, synthetic materials for calvarial reconstruction should be easily applicable, durable, and strong. In these aspects, a 3D titanium implant can be an optimal source material in calvarial reconstruction.

• Journal of Microbiology and Biotechnology
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• v.28 no.12
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• pp.2113-2120
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• 2018

Cross-reactive material 197 ($CRM_{197}$) is a non-toxic mutant of diphtheria toxin containing a single amino acid substitution of glycine 52 with glutamic acid. $CRM_{197}$ has been used as a carrier protein for poorly immunogenic polysaccharide antigens to improve immune responses. In this study, to develop a sandwich ELISA that can detect $CRM_{197}$ and $CRM_{197}$ conjugate vaccines, we generated a human anti-$CRM_{197}$ monoclonal antibody (mAb) 3F9 using a phage-displayed human synthetic Fab library and produced mouse anti-$CRM_{197}$ polyclonal antibody. The affinity ($K_D$) of 3F9 for $CRM_{197}$ was 3.55 nM, based on Bio-Layer interferometry, and it bound specifically to the B fragment of $CRM_{197}$. The sandwich ELISA was carried out using 3F9 as a capture antibody and the mouse polyclonal antibody as a detection antibody. The detection limit of the sandwich ELISA was <1 ng/ml $CRM_{197}$. In addition, the 3F9 antibody bound to the $CRM_{197}$-polysaccharide conjugates tested in a dose-dependent manner. This ELISA system will be useful for the quantification and characterization of $CRM_{197}$ and $CRM_{197}$ conjugate vaccines. To our knowledge, this study is the first to generate a human monoclonal antibody against $CRM_{197}$ and to develop a sandwich ELISA for $CRM_{197}$ conjugate vaccines.