• 대한인간공학회지
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• 제22권1호
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• pp.1-15
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• 2003

The resonance behaviour needs be understood to identify the mechanisms responsible for the dynamic characteristics of human body, to allow for the non-linearity when predicting the influence of seating dynamics, and to predict the adverse effects caused by various magnitudes of vibration. However, there are currently no known studies on the effect of vibration magnitude on the transmissibility to thoracic or lumbar spine of the seated person, despite low back pain(LBP) being the most common ailment associated with whole-body vibration. The objective of this paper is to develop a proper mathematical human model for LBP and musculoskeletal injury of the crew in a maritime vehicle. In this study, 7 degree-of-freedom including 2 non-rigid mass representing wobbling visceral and intestine mass, is proposed. Also, when compared with previously published experimental results, the model response was found to be well-matching. When exposed to various of vertical vibration, the human model shows appreciable non-linearity in its biodynamic responses. The relationships of resonance for LBP and musculoskeletal injury during whole-body vibration are also explained.

• 대한인간공학회지
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• 제22권1호
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• pp.57-67
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• 2003

The resonance behaviour needs be understood to identify the mechanisms responsible for the dynamic characteristics of human body, to allow for the non-linearity when predicting the influence of seating dynamics. and to predict the adverse effects caused by various magnitudes of vibration. However, there are currently no known studies on the effect of vibration magnitude on the transmissibility to thoracic or lumbar spine of the seated person. despite low back pain(LBP) being the most common ailment associated with whole-body vibration. The objective of this paper is to develop a proper mathematical human model for LBP and musculoskeletal injury of the crew in a maritime vehicle. In this study, 7 degree-of-freedom including 2 non-rigid mass representing wobbling visceral and intestine mass, is proposed. Also. when compared with previously published experimental results, the model response was found to be well-matching. When exposed to various of vertical vibration, the human model shows appreciable non-linearity in its biodynamic responses. The relationships of resonance for LBP and musculoskeletal injury during whole-body vibration are also explained.

• Fibers and Polymers
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• 제1권2호
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• pp.111-115
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• 2000

The effects of nitrile group substitution onto aromatic polyamide backbone on the gas permeability and permselectivity of the polymers are examined. The gas permeability of aromatic polyamides increase with increasing the content of nitrile group substitution, whereas the permselectivity decreases with increasing the nitrile group contents. The effects of chain linrearity on the permeability and permselectivity are also examined. The non-linearity of the polymers increases the permeability. These behaviors are interpreted in terms of chain packing and crystallinity of the aromatic polyamides.

• 천문학회보
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• 제39권2호
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• pp.62.1-62.1
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• 2014

Metallicity distribution of globular clusters (GCs) provides an important clue for star formation history of their host galaxy. With an assumption that GCs are generally old, GC colors have been used as a proxy of GC metallicities. Bimodal GC color distributions observed in most large galaxies have, for decades, been interpreted as bimodal metallicity distributions, indicating the presence of two populations within a galaxy. However, the conventional view has been challenged by a new theory that non-linear GC color-metallicity relations (CMRs) can cause a bimodal color distribution even from a single-peaked metallicity distribution. Using the photometric and spectroscopic data of NGC 5128 GCs in combination with stellar population simulation models, we examine the effect of non-linearity in GC CMRs on the transformation of GC color distributions into metallicity distributions. Although, in some colors, offsets are present between observations and models in the CMRs, their overall shape agrees well for various colors. After the offsets are corrected, the observed spectroscopic metallicity distribution is well reproduced via modeled CMRs from various color distributions having different morphologies. On the other hand, the linearly converted metallicity distributions from GC colors show a significant discrepancy with the observed spectroscopic metallicity distribution. We discuss the implications of our results.

• 천문학논총
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• 제30권2호
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• pp.261-263
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• 2015

The metallicity distribution of globular clusters (GCs) provides a crucial clue for the star formation history of their host galaxy. With the assumption that GCs are generally old, GC colors have been used as a proxy for GC metallicities. Bimodal color distributions of GCs observed in most large galaxies have, for decades, been interpreted as bimodal metallicity distributions, indicating the presence of two populations within a galaxy. However, the conventional view has been challenged by a new theory that non-linear GC color-metallicity relations can cause a bimodal color distribution even from a single-peaked metallicity distribution. Using photometric and spectroscopic data of NGC 5128 GCs in combination with stellar population simulation models, we examine the effect of non-linearity in GC color-metallicity relations on transformation of the color distributions into the metallicity distributions. Although in some colors offsets are present between observations and models for the color-metallicity relations, their overall shape agrees well for various colors. After the offsets are corrected, the observed spectroscopic metallicity distribution is well reproduced via modeled color-metallicity relations from various color distributions having different morphologies. We discuss the implications of our results.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.853-860
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• 2003

Relationship between axial strain and volumetric strain of Light-Weighted Foam Soil (LWFS) are investigated. LWFS is composed of the dredged soil from offshore, cement and foam to reduce the unit weight and also increase compressive strength. For this purpose. the triaxial compression tests are carried out on the prepared specimens of LWFS with various conditions such as initial water contents, cement contents, and curing stresses, The test results of LWFS Indicated that the axial strain - volumetric strain relationship is almost linearity with increase cement contents and the unit weight but the relationship is non-linearity with decrease cement contents and the unit weight. In this study, it is found that assuming no change of cross section area of LWFS, axial strain occurring the poisson's ratio of zero, that the axial strain same to volumetric strain, steeply increases with decrease the unit weight, initial water content, and cement contents.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(4)
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• pp.133-138
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• 1996

For the application of hydrogenated amorphous silicon (a-Si:H) p-i-n structural diode as the alpha particle spectroscopy, the induced charge collection was simulated based on a relevant non-uniform charge generation model. The simulation was accomplished for two extreme cases of the incident direction of alpha particle, p-and n-side, respectively. As expected, for the complete charge collection, the hole collection should be severely considered due to its poor mobility and the full depletion bias required. For the comparison of signal corresponding to the detector configuration or structure, although n-i-p configuration shows a wider range of linearity to the energy, p-i-n configuration is more suitable in the viewpoint of linearity and signal value for the considering energy range.

• 천문학논총
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• 제10권1호
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• pp.67-78
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• 1995

An introduction to the first CCD camera system in Bohyunsan Optica1 Astronomy Observatory(CCD#l) is presented. The CCD camera adopts modular dewar design of IfA(Institute for Astronomy at Hawaii University) and SDSU(San Diego State University) general purpose CCD controller. The user interface is based on IfA design of easy-to-use QUI program running on the NeXT workstation. The characteristics of the CCD#l including Gain, Charge Transfer Efficiency, rms Read-Out Noise, Linearity and Dynamic range is tested and discussed. The CCD#l shows 6.4 electrons RON and gain of 3.49 electrons per ADU, and the optimization resulted in about 27 seconds readout time guaranteeing charge transfer efficiency of 0.99999 for both direction. Linearity test shows that non-linear coefficient is $6{\times}10^{-7}$ in the range of 0 to 30,000 ADU.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.1050-1053
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• 2001

There is great interest in developing magnetoresistance(MR) sensor, using ferromagnetic, electrically non-magnetic conducting and antiferromagnetic films, especially for the use in weak magnetic fields. Here, we report single and Wheatstone-bridge type of MR sensors made in Si(001)/HiO(300$\AA$)/NiFe bilayers. Angular dependence of MR profiles was measured in Si(001)/NiO(300$\AA$)/NiFe(450$\AA$) films as a function of an angle between current and applied field direction, also, linearity was determined. AMR characteristics of single MR sensors was well explained with single domain model. Good linearity in 45$^{\circ}$Wheatstone-bridge type of MR sensors consisting of 4 single MR sensors made in Si(001)/NiO(300$\AA$)/NiFe(450$\AA$) was shown in the range of about $\pm$50 Oe.

• 센서학회지
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• 제28권5호
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• pp.289-293
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• 2019

This paper presents a remote patient monitoring system for diagnostic pure-tone audiometry. A pure-tone audiometer was developed for basic hearing screening; its performance was evaluated according to international standards in terms of linearity, accuracy, and total harmonic distortion. Pure-tone audiometry has a maximum hearing level of 104.9 dB HL that is comparable with other commercial products. The audiometer shows satisfactory linearity with a deviation of ${\pm}0.4dB$, an accuracy of ${\pm}0.025%$, and a total harmonic distortion (THD) of 0.21%. The remote patient monitoring systems include remote control devices based on wide area network (WAN) connections and an audiometer connected in series. Through experimentation, we successfully performed real-time diagnostic communication without delay in transferring audiometric data. This system is expected to supply domestic equipment in the audiometric market and to improve the quality of life of patients in non-clinical environments.