• Environmental Engineering Research
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• v.21 no.1
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• pp.58-68
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• 2016

The study explored droughts using the Standardized Precipitation Index (SPI) in the northwestern region of Bangladesh, which is the drought prone area. In order to assess the trend and variability of monthly rainfall, as well as 3-month scale SPI, non-parametric Mann-Kendall (MK) tests and continuous wavelet transform were used respectively. The effect of climatic parameters on the drought in this region was also evaluated using SPI, with the Southern Oscilation Index (SOI) by means of the wavelet coherence technique, a relatively new and powerful tool for describing processes. The MK test showed no statistically significant monthly rainfall trends in the selected stations, whereas the seasonal MK test showed a declining rainfall trend in Bogra, Ishurdi, Rangpur and Sayedpur stations respectively. Sen's slope of six stations also provided a decreasing rainfall trend. The trend of the SPI, as well as Sen's slope indicated an increasing dryness trend in this area. Dominant periodicity of 3-month scale SPI at 8 to 16 months, 16 to 32 months, and 32 to 64 months were observed in the study area. The outcomes from this study contribute to hydrologists to establish strategies, priorities and proper use of water resources.

• SUVANNABHUMI
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• v.11 no.2
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• pp.25-57
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• 2019

The paper addresses Erik Cohen's pioneering work on tourism in Thailand, specifically his publications on the relations between Thai women and foreign (farang) men in tourist-oriented encounters. Of sociological-anthropological interest is his conceptualization of these relations as "open-ended prostitution as a skilful game of luck" based on his study of a Bangkok soi (lane) in 1981-1984, and his exploration of Thai culture in terms of ambiguity and contradiction. On the basis of recent ethnographic research in the northern Thai tourist hub of Chiang Mai and wide-ranging observations on tourism development in Thailand, we examine continuity and change in these male-female engagements since Cohen's research, especially in the context of the increasing availability of such electronic agencies as social media, messaging, video chat, and internet dating. Whereas Cohen's concept of ambiguity and illusion has tended to disappear from physical spaces, it seems to have resurfaced in virtual space. The complexities of host-guest relations, and particularly the interactions both within the variegated category of "guests" themselves and then between their "hostesses" are explored in terms of sites of tourism-oriented encounters in both physical and virtual space so as to deconstruct these oppositional categories which have been formative in studies of tourism.

• Proceedings of the Korean Geotechical Society Conference
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• 1991.10a
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• pp.362-375
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• 1991

Background and Necessity of the study : For more than 20 years, the soil engineering reserach group of Chonnam National University has been performing the deformation analysis of soft clayey foundation, since the University is located near the south-western coast of Korean Peninsulla, along which tide reclamation works have been under proaressing. Associsted with the fact mentioned above, the researchers have been developing a computer program in order to carry out deformation analysis of soft foundation since early 1980. Case-studies : In this research, the Biot's equation was selected as the governing equation coupled with several constitutive models including original and modified Cam-clay models, elasto-viscoplastic model, Lade's model etc. The anisotropy of soi1 can be considered in this program. To validate the accuracy of the computer program developed a couple of case-studies were performed. These include the pilot banking, sand drain considering smear effect and compound foundation reinforced with sheet pile into soft foundation.i) The pilot banking Good results could be acquired by assuming banking load as the body force composed of finite element mesh rather than equivalent concentrated load.ii) The sand drain Due to smear, the delay of consolidation was remarkable at the early stsge. so safety for the failure of foundation should be checked for the initial step of consolidation. iii) The compound foundation Accurate results were obtained by introducing the joint element method for the soft foundation reinforced with sheet pile into soiㅣ.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.872-875
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• 2004

In this paper, thermal response analysis of a temperature controlled three-axis accelerometer for high temperature environments with integrated micro-heaters and temperature sensors is investigated with finite element method (FEM) program, ANSYS and infrared thermal measurement systems. And availability to application fields from a viewpoint about short thermal response time is discussed. In this paper, the time of three-axis accelerometer for high temperatures becoming $300^{\circ}C$ by integrated micro-heaters and temperature sensors to reduce thermal drift characteristics was analyzed as a thermal response time of this device. The simulated thermal response time (time until SOI piezoresistors actually becomes $300^{\circ}C$) of three-axis accelerometer for high temperatures with ANSYS is about 0.6s, and measured result with infrared temperature measurement systems is about 0.64s. Experimental results using infrared thermal measurement systems agreed well with these theoretical results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1127-1134
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• 2017

Gas turbine engine control was originated from a single hydro-mechanical governor for fuel metering and changed to 1970s' DEEC and then today's centralized FADEC. In order to attain the goal of improvement of control performance, application of PHM technology, and reduction of system weight, it is necessary to make a transition to distributed engine control. This paper describes the concept and roadmap of distributed control, collaborative efforts of government and industry for successful development of the system, and technical challenges for the system.

• Journal of Haehwa Medicine
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• v.4 no.2
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• pp.335-336
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• 1996

Artemisinin, a new antimalarial to treat patients infected with strains of Plasmodium jalciparum, derived from the plant Artemisia annua Linn, has immunopharmacologic actions such as enhence the PHA -induced lymphocyte transformation rate, increased the weight of spleen but reduced the weight of thymus, reduced phagocytic function of peritoneal macrophage, remarkably reduced the level of serum IgG and hemolysin fonning capacity (sentitized with SRBC), inhibited the activity of Ts cells of donor mice by supraoptimal immunuization(SOI), but enhenced activity of Ts cells of recipient mice by SOI. These results suggested that Ts cells may be the target cells of artemisinin. To the serum complement C3 level of plasmodium berghei-infeted mice, artemisinin (i. m,) could remarkly increase it. The artemisinin also obviously reduced the prostaglandin E(PGE) in the mouse hind paw swelling induced by carrageenin. Numerous studies have demonstrated that pharmacologic doses of PGE attenuate the development of immunocomplex nephritis. Some autologous immune mechanisms may be invoolved In the pathogensis of some types of glomurulonephritis. Glomerular abnormalities can be induced in animals by variety of immunological manipulations. The resulting disorder has many clinical and pathogical similarities to the disease in human. Our purpose was therefore to test the ability of the artemisinin to lessen the severity of rabbit IgG accelerated nephrotoxic serum glomerulonephritis in mice model. Mice which had treated with rabbit IgG and NTS, administrated with saline, showed Significant inceases of urinary protein, cholesterol level, and decrease of serum albumin in NS group. On the contrary, By i.g. adminstration of artemisinin at dose of 12.5, 25 and 50 mg/kg for 14 days after NTS injection, shown that artemisinin inhibited the nephritic changes in some parameters by means of urinary protein(p<0.05, p<0.01) and serum choleterol(p<0.05, p<0.01) and albumin (p<0.05, p<0.01), blood urea nitrogen (p<0.05, p<0.01), serum albumin(p<0.05, p<0.01); Cyclophosphamide(i.p. 10mg/kg for 14d) had almost same effect as the artemisinin had. Morphological studies shown that The picture of kidney from the mouse with NTS-nephritis accerated with rabbit IgG, treated with i.g. saline as the control, the mesangiocapillary were enlarged and proliferated; There were inflammatory cells infiltrating around the glomeruli; The ethelial cell were proliferated in the wall of Bowman's capsule. Histopatholological picture of kidney from the NTS-nephritis accerated with rabbit IgG mouse treated with i.p. 10mg/kg cyclophosphamide as the positive control. No siginicant histopathological evidence were found. Treaded with i.p. 12.5mg/kg artemisinine, the picture shown that mesangiocapillary were lightly proliferated; There were inflammatory cells infiltrating around the glomeruli; Treaded with i.p. 25mg/kg artemisinine, The picture shown that the mesangiocapillary were lightly proliferated; Treaded with i.p. 50mg/kg artemisinine, The picture shown that both the mesangiocapillary proliferated and the inflammatory cells infiltrating around the glomeruli are less than treated with saline, 12.5 and 25 mg/kg artemisinine. On the basis of these studies we conclude that the artemisinin can relieve pathological change caused by NTS-nephritis aacerated with rabbit IgG.

• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.1
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• pp.52-58
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• 2006

Single-electron transistor (SET)-based logic cells and SET/FET hybrid integrated circuits have been fabricated on SOI chips. The input-output voltage transfer characteristic of the SET-based complementary logic cell shows an inverting behavior where the output voltage gain is estimated to be about 1.2 at 4.2K. The SET/FET output driver, consisting of one SET and three FETs, yields a high voltage gain of 13 and power amplification with a wide-range output window for driving next circuit. Finally, the SET/FET literal gate for a multi-valued logic cell, comprising of an SET, an FET and a constant-current load, displays a periodic voltage output of high/low level multiple switching with a swing as high as 200mV. The multiple switching functionality of all the fabricated logic circuits could be enhanced by utilizing a side gate incorporated to each SET component to enable the phase control of Coulomb oscillations, which is one of the unique characteristics of the SET-based logic circuits.

• Analytical Science and Technology
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• v.23 no.4
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• pp.347-356
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• 2010

Emission characteristics of major offensive odorants were investigated using odor samples collected from two urban stormwater catch basins with highly contrasting environmental conditions. A total of 6 major offensive odorants ($H_2S$, $CH_3SH$, DMS, DMDS, $CH_3CHO$ (AA), and $NH_3$) were measured. For this comparative analysis, odor intensity (OI) of all odorants was derived from their concentration data via empirical equations introduced by Nagata. Both the absolute magnitude of odorant concentrations and their OI values were used concurrently to evaluate the occurrence pattern of each individual odorant. According to our analysis, RSCs including $CH_3SH$, $H_2S$, and DMS tend to exhibit the highest odor strengths among all 6 compounds investigated. The overall results of our study suggest that the emissions of major offensive odorants from urban stormwater catch brains can be explained at least partially by the temporal trend of human activity.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1542-1543
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• 2007

This paper presents the effect of driving waveform for piezoelectric bend mode inkjet printhead with optimized mechanical design. Experimental and theoretical studies on the applied driving waveform versus jetting characteristics were performed. The inkjet head has been designed to maximize the droplet velocity, minimize voltage response of the actuator and optimize the firing frequency to eject ink droplet. The head design was carried out by using mechanical simulation. The printhead has been fabricated with Si(100) and SOI wafers by MEMS process and silicon direct bonding method. To investigate how performance of the piezoelectric ceramic actuator influences on droplet diameter and droplet velocity, the method of stroboscopy was used. Using the water based ink of viscosity of 11.8 cps and surface tension of 0.025N/m, it is possible to eject stable droplets through 64 nozzles average velocity of 4.05 m/s with standard deviation of 0.06 m/s and average diameter of $29.2\;{\mu}m$ with standard variation of $0.5\;{\mu}m$.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.2
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• pp.32-38
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• 2004

This study was performed to investigate the behavior of liquid and vapor phase of fuel mixtures with different piston cavity diameters in a optically accessible engine. The conventional engine was modified as Central Injected DI gasoline engine with swirl motion. Two dimensional spray fluorescence images of liquid and vapor phase were acquired to analyze spray behavior and fuel distribution inside of cylinder using exciplex fluorescence method. Piston cavity geometries were set by Type S, M and L. The results obtained are as follows. In the spray formation after SOI, the cone angle and width of the spray were decreased at late injection timing. With a fuel injection timing of BTDC $180^{\circ}C$, fuel was not greatly affected in a piston cavity but generally distributed as homogeneous mixture in the cylinder. With a fuel injection timings of BTDC $90{\circ}C$ and $60^{\circ}C$, fuel mixture was widely distributed in near the cavity center. As a injection timing was late in the compression stroke, residual width of fuel mixture was narrow in proportion to piston cavity.