• Title/Summary/Keyword: mixed spread

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Experiments on the Influence of Opening of Natural Smoke Ventilators on the Stack Effect in High-rise Mixed-use Residential Buildings (초고층주상복합건물에서 배연창 개방이 연돌효과에 미치는 영향에 대한 실험적 연구)

  • Lim, Chae-Hyun;Kim, Bum-Gyu;Park, Yong-Hwan
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.3
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    • pp.89-94
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    • 2009
  • The stack effect in high-rise buildings is expected more significant at nights in winter due to the large temperature difference between the inside and outside of the buildings. However, the existence of large openings such as natural ventilators on the floor may effect the position of neutral plane, smoke spread at fire and thus obstruct the door openings for rescue. In this paper, the vertical and horizontal pressure distribution with different openings of natural smoke ventilators was experimentally analyzed by investigating pressure differentials.

The Successful Strategies for YouTube Channels Using the Network Overlap (네트워크 중복을 이용한 유튜브 채널의 성공 전략)

  • Shin, Jin-Hee;Son, Jung-Min
    • The Journal of Information Systems
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    • v.29 no.1
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    • pp.267-287
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    • 2020
  • Purpose Online platform companies can increase the spread of content by communicating with users who have diverse preferences through social networks. Previous studies show the mixed effect on the network overlap, and there was a limited examinations for the underlying mechanism. This study expects high academic and practical implications that can be provided by studying on the user's viewership network. The purpose of this research is to examine the effects of network overlap on the users' viewership for creators of user-generated content in YouTube. We explain the direct and in-direct effects through the content sharing and the valence of user ratings. Design/methodology/approach The data contains 45 channels and 4,085 video clips from YouTube. We control the effect of the categories, channel characteristics, and vide clip characteristics on the viewership. PROCESS macro were used to analyze the direct and in-direct effects of network overlap. Findings The analysis results showed that the network overlap directly affect on the users' viewership. The variable decreases the moderators (i.e., content sharing and the valence of user ratings). This result implies that the users can not satisfy their need for uniqueness which is achieved by content sharing and rating in the overlapped network.

Numerical Analysis on Changes in Flowrate of Draft Water and Power by Changing Design Parameters of a Long-Distance Water Circulation (저층수 흡입식 광역 순환장치의 설계변수에 따른 배출량 및 소비동력 변화 특성에 대한 수치 해석 연구)

  • Song, Dong-Keun;Hong, Won-Seok;Kim, Young-Cheol;Park, Myong-Ha
    • The KSFM Journal of Fluid Machinery
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    • v.13 no.1
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    • pp.23-28
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    • 2010
  • A draft tube which has impeller to elevate bottom water and spread it over surface of lake water, induces convective circulation of lake water, a Long-Distance Circulation (LDC). Circulation of lake water make stratified water mixed and enhance DO (Dissolved Oxygen) of bottom water. Circulation rate of water is determined by draft rate of the tube, which is dependent on design parameters of the draft tube system, i. e. dimension of impeller and diffuser, inclined angle of impeller, impeller shape, and rotational speed. In this study, change in draft rate and power consumption of circulation equipment was investigated numerically with changing impeller dimension, angle and rotational speed. It was found that flowrate of draft water was increased as the dimensions of draft tube and impeller, and rotational speed and inclined angle of impeller increased. The power consumption was also elevated with increasing parameter values, and final selection of parameter values was made to satisfy target flowrates and power consumption.

Room Temperature Growth of Magnetite Films on Arachic Acid Monomolecular Layers

  • Ishihara, Takashi;Kitamoto, Yoshitaka;Shirasaki, Fumio;Abe, Masanori
    • The Korean Journal of Ceramics
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    • v.6 no.4
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    • pp.401-404
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    • 2000
  • Mimicking the bacterial synthesis of magnetosomes, in which the functionalized surface of a cytoplasmic (lipid) membrane is considered to be stimulating the crystal growth of magnetite, we have successfully grown magnetite films at $30^{\circ}C$ using an arachic acid monomolecular layer as a functionalized surface. The lipid monomolecular layer was spread on an aqueous solution of FeCl$_2$ which was oxidized by flowing a mixed gas, with ratio $O_2$/$N_2$=1/2000, on the surface of the lipid layer. Mossbauer and X-ray diffraction analyses revealed that the Fe$_3$O$_4$ films contain small amounts of ferric hydroxyl impurity phases of ${\alpha}$-FeOOH and ${\tau}$-FeOOH. This is because the oxygen partial pressure at the ferrite/aqueous interface changed as the film (through which the gas penetrated) increased in thickness. Methods to obtain single phase magnetite films are proposed.

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A study on the contradiction of KwanKyuk(關格) in Naegyung("內經") and Nankyung("難經") ("내경(內經)"과 "난경(難經)"의 관격(關格)의 모순에 대한 연구(硏究);"증치준승(證治準繩)", "경악전서(景岳全書)", "의학입문(醫學入門)" 등을 중심으로)

  • Jo, Hak-Jun;Kim, Ho-Hyun
    • Journal of Korean Medical classics
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    • v.20 no.1
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    • pp.49-63
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    • 2007
  • Referred to "Jeungchijunseung(證治準繩" ), "Kyungakjunsu(景岳全書)", and "Uihakyipmoon(醫學入門)", We got the conclusion on the contradiction of KwanKyuk in "Naegyung(內經)" and "Nankyung(難經)" like below. First, It can be defined the fact as Naekwanoikyuk(內關外格) in "Nankyung(難經)" that in "Naegyung(內經)", the Cold from out is too strong that the Yanggi is isolated and vomitted and spread to Hacho(下焦). Because, it is the same phenomenon in "Nankyung(難經)", Yanggi is too strong that invade the stage of Eumgi, and in the flow, overturning situation appears and thru isolation. Same above, We can also understand the fact as Oikwannaekyuk(外關內格) in "Nankyung(難經)" that the Ileum(溢陰, same as Naekwan(內關) or Kwaneum(關陰) in "Naegyung(內經)" ), Heat from Mixed disease(雜病) is too strong that Eumgi is isolated and spreading to Sangcho(上焦). Because, it is the same phenomenon in "Nankyung(難經)" , Eumgi is too strong that invade the stage of Yanggi, and in the flow, overflowing situation appears and thru vomitting.

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Mycobacterium abscessus Skin Infection Associated with Shaving Activity in a 75-year-old Man

  • Choi, Hoon;Kim, Yong Il;Na, Chan Ho;Kim, Min Sung;Shin, Bong Seok
    • Annals of Geriatric Medicine and Research
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    • v.22 no.4
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    • pp.204-207
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    • 2018
  • Mycobacterium abscessus comprises rapidly growing mycobacteria, and the clinical manifestations of M. abscessus skin infection include papule, nodule, ulcer, scar and mixed form. The cutaneous infections have been reported due to minor trauma, cosmetic therapy, acupuncture and disseminated infection. A 75-year-old man presented with pruritic diffuse various sized erythematous papuloplaques and pustules on the neck and chest for 2 months. The cutaneous lesions were spread around the wound of the shaving on the neck. The histopathologic findings were consistent with abscess showing infiltrations of neutrophils and lymphocytes in the dermis and negative findings were observed on immunohistochemical stain including acid-fast bacilli stain. One month later, mycobacterial culture result showed positive findings, and the pathogen was identified by reversetranscriptase polymerase chain reaction with hybridization. The patient was treated with combination of clarithromycin and ethambutol for 5 months and there is no evidence of recurrence after 6 months of follow-up. Herein, we report a case of M. abscessus cutaneous infection through minor trauma caused by shaving in the elderly.

A Review on Fire Safety Engineering: Key Issues for High-Rise Buildings

  • Li, Guo-Qiang;Zhang, Chao;Jiang, Jian
    • International Journal of High-Rise Buildings
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    • v.7 no.4
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    • pp.265-285
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    • 2018
  • This paper presents a state-of-the-art review on the design, research and education aspects of fire safety engineering (FSE) with a particular concern on high-rise buildings. FSE finds its root after Great Fire of Rome in 64 AD, followed by Great London Fire in 1666. The development of modern FSE is continuously driven by industry revolution, insurance community and government regulations. Now FSE has become a unique engineering discipline and is moving towards performance-based design since 1990s. The performance-based fire safety design (PBFSD) involves identification of fire safety goals, design objectives, establishment of performance criteria, and selection of proper solutions for fire safety. The determination of fire scenarios and design fires have now become major contents for PBFSD. To experience a rapid and positive evolution in design and research consistent with other engineering disciplines, it is important for fire safety engineering as a profession to set up a special educational system to deliver the next-generation fire safety engineers. High-rise buildings have their unique fire safety issues such as rapid fire and smoke spread, extended evacuation time, longer fire duration, mixed occupancies, etc., bringing more difficulties in ensuring life safety and protection of property and environment. A list of recommendations is proposed to improve the fire safety of high-rise buildings. In addition, some source information for specific knowledge and information on FSE is provided in Appendix.

Plan for Risk Reduction of Smart Factory Process through Accident Analysis and Status Survey (재해분석과 실태조사를 통한 스마트 팩토리 공정의 위험성 감소 방안)

  • Byeon, Junghwan
    • Journal of the Korean Society of Safety
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    • v.37 no.5
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    • pp.22-32
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    • 2022
  • The domestic smart factory is being built and spread rapidly, mainly by mid-sized companies and large enterprises according to the government's active introduction and support policy. But these factories only promote production system and efficiency, so harmfulness and risk factors are not considered. Therefore, to derive harmful risk factors in terms of industrial safety for 12,983 government-supported smart factory workplaces from 2014 to 2019, industrial accident status analysis compared workplaces with automation facilities and government-supported workplaces with automation facilities. Also, to reduce risks associated with domestic smart factory processes, twenty government-supported workplaces with automation facilities underwent analysis, evaluating risks through a status survey using the process evaluation table. In addition, the status survey considered region, size, industry, construction level, and accident rate; the difference in risk according to the structure of the process was confirmed. Based on the smart factory process evaluation results, statistical analysis confirmed that serial, parallel, and hybrid structures pose different risk levels and that the risks of mixed structures are greater. Finally, safety control system application was presented for risk assessment and reduction in the smart factory process, reflecting the results of disaster analysis and actual condition investigation.

Deflection and bending characteristics of embedded functionally graded porous plate with bi-directional thickness variation subjected to bi-sinusoidal loading

  • Rajat Jain;Mohammad Sikandar Azam
    • Steel and Composite Structures
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    • v.51 no.6
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    • pp.601-617
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    • 2024
  • This work aims to explore the static behaviour of a tapered functionally graded porous plate (FGPP) with even and uneven porosity distributions resting on two parametric elastic foundations. The plate under investigation is subjected to bi-sinusoidal loading and the edges of the plate are exposed to different combinations of edge restrictions. In order to examin the static behaviour, bending factors (BF) related to bending and normal stresses have been evaluated using classical plate theory. To achieve this, the governing equations have been derived employing the energy concept. And to solve it, the Rayleigh-Ritz method with an algebraic function has been utilised; it is simple, precise, and computationally intensive. After convergence and validation analyses, new findings are made available. The BF of the plate have been exhaustively examined to explain the influence of aspect ratios, material property index, porosity factor, taper factor, and Winkler and Pasternak stiffness. It is observed that the BF of an elastically supported FGPP are influenced by the index of material propery and the aspect ratio. Findings also indicate that the impact of porosity is more when it is spread evenly, as opposed to when it is unevenly distributed. Further, the deformed plate's structure is significantly influenced by the different thickness variations. Examination of bending characteristics of FGPP having different new cases of thickness variations with different types of porosity distribution under fifteen different mixed edge constraints is the prime novality of this work. Results presented are reliable enough to be taken into account for future studies.

The Effects of Korean Traditional Sauces on Quality Characteristics of Hanwoo Semitendinosus Dry-cured Ham (한국 전통장류가 한우 반힘줄모양근(M. Semitendinosus)으로 제조한 건염햄의 육질 특성에 미치는 영향)

  • Seong, Pil-Nam;Cho, Soo-Hyun;Kang, Geun-Ho;Kim, Dong-Hoon;Park, Beom-Young;Kang, Sun-Moon;Park, Kyoung-Mi
    • Food Science of Animal Resources
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    • v.33 no.6
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    • pp.757-762
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    • 2013
  • This study was conducted to develop a processing method for dry-curing beef ham with Korean traditional sauces and to investigate the quality properties of the dry-cured beef hams. Semitendinosus muscle from Hanwoo was spread with sundried salt (C), sun-dried salt mixed with red pepper paste (T1), and sun-dried salt mixed with soybean paste (T2), and inserted into washed Hanwoo large intestine. It was then dried and fermented for 75 d. Moisture contents of the hams were 46-48%, without any significant differences. T1 showed the lowest pH among the three dry-cured hams, while water holding capacity (WHC) of T2 was found the lowest (p<0.05). In mechanical color determination, C showed higher CIE $a^*$ and CIE $b^*$ than T1 and T2 (p<0.05), however CIE $L^*$ did not show any significant difference. In texture, T1 demonstrated significantly lower springiness than C (p<0.05). The sensory properties of all dry-cured hams did not show any significant difference, but T1 indicated a higher taste, saltiness and overall acceptability than others, whereas C gathered the highest score in color and flavor. In conclusion, the dry-curing by combination of sun-dried salt mixed with red pepper sauce (T1) showed higher quality properties of the Hanwoo dry-cured ham.