• Advances in Computational Design
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• v.2 no.2
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• pp.107-119
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• 2017

The Micro circular diaphragm (MCD) is the mechanical actuator part used in the micro electro-mechanical sensors (MEMS) that combine electrical and mechanical components. These actuators are working under harsh mechanical and thermal conditions, so it is very important to study the mechanical and thermal behaviors of these actuators, in order to do with its function successfully. The objective of this paper is to determine the thermo-mechanical behavior of MCD by developing the traditional bulge test technique to achieve the aims of this work. The specimen is first pre-stressed to ensure that is no initial deflection before applied the loads on diaphragm and then clamped between two plates, a differential pressure (P) and temperature ($T_b$) is leading to a deformation of the MCD. Analytical formulation of developed bulge test technique for MCD thermo-mechanical characterization was established with taking in-to account effect of the residual strength from pre-stressed loading. These makes the plane-strain bulge test ideal for studying the mechanical and thermal behavior of diaphragm in both the elastic and plastic regimes. The differential specimen thickness due to bulge effect to describe the mechanical behavior, and the temperature effect on the MCD material properties to study the thermal behavior under deformation were discussed. A finite element model (FEM) can be extended to apply for investigating the reliability of the proposed bulge test of MCD and compare between the FEM results and another one from analytical calculus. The results show that, the good convergence between the finite element model and analytical model.

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.06a
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• pp.142-145
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• 2004

The purpose of this study was to characterize background mass concentration of fine particle PM10 and metallic composition from September 2001 to August 2002 in comparison with a medium-sized city, Asan and a metropolitan city, Seoul. Annual mean PM10 concentrations in Asan and Seoul were 47.98 and $75.33\;{\mu}g\;/\;m^3$, respectively. The concentrations of PM10 were highest in spring season in both cities. The concentrations of measured metals except As and Pb in Asan were higher than those in Seoul. Yellow dust could affect the mass and metals concentrations of measured PM10 in Asan and Seoul. Relationship between measured metals concentrations showed that Si and Fe were associated with natural sources such as soil. Pb, Cu and Zn were closely related to urban anthropogenic sources such as fuel combustion. Especially, relationship between metals showed different association during yellow dust. Proper management for fine particles is warranted in Asan, considering the concentrations of metallic elements in fine particles in Asan were relatively higher than those in Seoul.

• Journal of Environmental Science International
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• v.13 no.3
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• pp.205-214
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• 2004

This study focuses on the measurement of airborne Volatile Organic Compounds (VOCs) in the Kumi electronic industrial complex during the time periods of August and September, 2002 and January and February, 2003. This study was based on the US-EPA method TO-14 while the VOCs were analyzed with GC/MSD. The toluene level revealed high concentration at all measurement sites. The areal rank of average concentrations of VOCs is as follows: industry1 > industry2 > urban > middle > residential. Concentrations of VOCs in Kumi electronic industrial ones were generally higher than at Yeochon and Ulsan industrial complexes. Dichloromethane and trichloroethylene, which are used as a cleaner in the process of electronic industries, were observed 4 to 8 times higher than those of other areas. Among the aromatic compounds, toluene showed the highest level, while the concentrations of dichloromethane and trichloroethylene were higher than those of other halogen compounds. In Kumi, toluene, trichloroethylene, and dichloromethane were confirmed as the major compounds of VOCs by this research.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.1
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• pp.50-62
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• 2011

Temporal trends and spatial distributions of ozone concentrations in Pohang were investigated using data measured at 4 air quality monitoring stations (i.e., Daedo, Jukdo, Jangheung, and Desong) during 2002-2006. The monthly mean ozone concentrations were highest during April and June and decreased during July and August, which follows the typical trend in the Northeast Asia region. The high springtime ozone concentration might have been strongly influenced by the enhanced photochemical ozone production of accumulated precursors during the winter under increased solar radiations. In July and August, ozone levels were decreased by frequent and severe precipitation that caused lower mean monthly solar radiation and efficient wash-out of ozone precursors. This suggests that precipitation is extremely beneficial in the aspect of ozone pollution control. High ozone concentrations exceeding 80ppb dominantly occurred in May and June during the late afternoon between 16:00~17:00. Ozone concentrations were higher in Jangheung and Daesong relative to Daedo and Jukdo, whereas total oxidants $(O_3+NO_2)$ were higher in Jangheung and Daedo. In the suburban area of Daesong, ozone concentrations seem to be considerably higher than those in urban sites of Daedo and Jukdo due to lower ozone loss by NO titration with lower local NO level.

• Structural Engineering and Mechanics
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• v.34 no.6
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• pp.755-778
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• 2010

Near-fault ground motion with directivity or fling effects is significantly influenced by the rupture mechanism and substantially different from ordinary records. This class of ground motion has large amplitude and long period, exhibits unusual response spectra shapes, possesses high PGV/PGA and PGD/PGA ratios and is best characterized in the velocity and the displacement time-histories. Such ground motion is also characterized by its energy being contained in a single or very few pulses, thus capable of causing severe damage to the structures. This paper investigates the characteristics of near-fault pulse-like ground motions and their implications on the structural responses using new proposed measures, such as, the effective frequency range, the energy rate (in time and frequency domains) and the damage indices. The paper develops also simple mathematical expressions for modeling this class of ground motion and the associated structural responses, thus eliminating numerical integration of the equations of motion. An optimization technique is also developed by using energy concepts and damage indices for modeling this class of ground motion for inelastic structures at sites having limited earthquake data.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.335-339
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• 2003

The estimation of seawater intrusion into deep aquifers has been becoming an important subject in terms of site characterization for geological disposal of radioactive waste. Conventional direct-current resistivity methods have been used for ground water explorations and recently have been applied to environmental problems. However, electromagnetic methods are more practical and useful for such a deep investigation. We consider audio-frequency magnetotelluric (AMT) and surface-to-borehole electromagnetic (EM) tomography methods as promising tools for the investigation of deep aquifer. These methods were tested in the Hasunuma area, Chiba Prefecture, Japan. Although the study area is in an urban area, high-quality AMT data were acquired, which was mainly accomplished by night-time data recording and remote-reference data processing. One-dimensional inversion results of the AMT data revealed two extremely conductive zones, which is consistent with the electrical conductivity profile of pore water in core samples. It can be interpreted as the seawater intrusions into both zones. However, the chemical analysis of the groundwater sampled in the deep zone suggests that this groundwater must be fossil seawater that had been confined during sedimentation processes. In addition, the permeability coefficient of the deep layer is very low. Thus the deep conductive zone corresponds to the fossil seawater regarded as being difficult to flow.

• Journal of Microbiology
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• v.41 no.2
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• pp.73-77
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• 2003

Four proteolytic bacteria were isolated and identified from a rotating biological contactor based on Bacillus. The four isolates, Ni 26, 36, 39 and 49 were identified as B. vallismortis, B. subtilis, Aeromonas hydrophila and B. amyioliquefaciens, respectively, based on their biochemical properties and 16S rDNA sequence analyses. The optimal proteolytic activity was observed in the temperature and pH ranges of 40-70$^{\circ}C$ and 8.0-8.5, respectively. The proteolytic activities of all the isolates were partially inhibited by phenylmethylsulfonylfluoride (PMSF), and the isolates Ni 26, Ni 39 and Ni 49 were inhibited by the metalloprotease inhibitor, 1,10-phenanthroline. Zymographic analyses of the culture supernatants revealed the presence of at least two pretenses in all isolates.

• Journal of Environmental Science International
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• v.19 no.7
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• pp.799-806
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• 2010

In an effort to characterize temporal and spatial variability of $PM_{10}$ and to quantitatively estimate contribution of sea salt aerosol to $PM_{10}$ mass in Busan area, twenty four-hour averaged concentration of $PM_{10}$ were measured in two distinct areas, Gwaebeopdong(inland) and Dongsamdong(seashore), Busan for summer and fall, 2007. It was found that sea salt accounted for 2.9% and 9.5% of $PM_{10}$ mass in Gwaebeopdong and Dongsamdong, respectively for the study period, indicating that contribution of sea salt to $PM_{10}$ mass and total ion concentration in seashore area were consistently higher by a factor of three compared to inland area. Temporal analysis suggested that sea salt contributions to $PM_{10}$ in Dongsamdong were higher in summer due to the southerly sea breeze while there was no significant fluctuation of sea salt contribution for the summer and fall months in Gwaebeopdong. Sea salt enrichment factors($EF_{sea}$) of $K^+$ $Ca^{2+}$ and ${SO_4}^{2-}$ (>10) indicated major contributions from anthropogenic sources and EFs of $Mg^{2+}$ and $Cl^-$ exhibited strong association with oceanic origins for both areas.

• The Journal of Society for e-Business Studies
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• v.19 no.1
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• pp.79-93
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• 2014

IT industry that main domain is future growth engines and convergence industry is based on national development through convergence others industry. However, shortage of advanced IT workforce is not limited to the region and urban. But, Previous studies is comprehensive research on human resource development. Human resource development studies, performance analysis and policy studies, are lacking to achieve the characterization in the region. Accordingly, The need for institutional improvement are appearing for activated regional industry through advanced Human resource development and IT convergence. in this study, we propose in order to improve institutions through IT sector performance evaluation.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.521-531
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• 2018

This paper presents a procedure for field measurements which provides a generalized Narrowband Power Line Communications (NB-PLC) channel model for low voltage (LV) access network in order to deploy advanced metering infrastructure (AMI) within Lahore, Pakistan. The measurements of allocated sites were performed in the residential (urban and rural), industrial and commercial electricity consumers for the NB-PLC channel modeling of overhead transmission lines (TLs). On the basis of extensive field measurement results, the average attenuation profile and transfer functions are presented. The results obtained from field measurements are validated by comparing them with a proposed Simulink model. A close agreement in the measured and simulated transfer function (TF) results is observed. The proposed Simulink model is an effort to model the NB-PLC channels in an effective way, especially in South Asian countries.