• Asian Journal of Atmospheric Environment
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• v.12 no.3
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• pp.274-288
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• 2018

Quantitative data of 50 non-polar organic compounds constituting $PM_{2.5}$ were continuously collected and analyzed from June 2016 to October 2017 (approximately 17 months) at Ichihara, one of the largest industrial areas in Japan. Target non-polar organic compounds including 21 species of polycyclic aromatic hydrocarbons (PAHs), 24 species of n-alkanes and 5 species of phthalate esters(PAEs) were simultaneously measured by gas chromatography/mass spectrometry. Basically, the average concentrations of the total PAHs, n-alkanes and PAEs in each season remained nearly level, and seasonal variations were little throughout the study period. These results suggest that the emission sources, which are not influenced by the seasons, are the dominant inputs for the target organic compounds. Diagnostic ratios of PAHs, assessment of n-alkane homologue distributions, carbon preference index, and the contribution of wax n-alkanes from plants were used to estimate source apportionments. These results indicate that anthropogenic sources were the main contributor for most PAHs and n-alkanes throughout the study period. The concentrations of PAEs selected in this study were low because emission amounts of these chemicals were little within the source areas of the sampling site. To our knowledge, this study is the first attempt to simultaneously measure a high number of non-polar organic compounds in $PM_{2.5}$ collected from the ambient air of Japan, and the resultant data will provide valuable data and information for environmental researchers.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.712-714
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• 2003

The modifications taking place within the alluvial plains impart a larger extent of disturbances to hydrologic systems. The objective of the present investigation is to detect the sensitivity of multi-temporal image data from Landsat TM (Thematic Mapper) for finding out the land-cover/land-use changes associated with alluvial low land. The eastern coast of Chiba Prefecture, Japan, forms a very important geographic unit owing to the existence of a unique alluvial landform. The alluvial plain occupied in the study area is widely known as 'Kujukuri Plain'. The TM images have been classified by means of maximum likelihood supervised classifier and the extent of changes has been estimated.

• Asian Journal of Atmospheric Environment
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• v.9 no.1
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• pp.66-77
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• 2015

In order to survey the seasonal variation of the chemical composition of particulate matter of $2.5{\mu}m$ or less ($PM_{2.5}$), $PM_{2.5}$ was sampled from 8 February 2013 to 31 March 2014 in an industrial area of Chiba Prefecture, Japan. Chemical measurements of the sample included: ionic components ($Na^+$, $NH_4{^+}$, $Ca^{2+}$, $Mg^{2+}$, $K^+$, $Cl^-$, $NO_3{^-}$ and $SO_4{^{2-}}$), carbonaceous components - organic carbon (OC) and elemental carbon (EC), and water-soluble organic carbon (WSOC). Also, secondary organic carbon (SOC) was measured based using the EC tracer method, and char-EC and soot-EC were calculated from the analytical results. The data obtained were interpreted in terms of temporal variation. Of the overall mean value of $PM_{2.5}$ mass concentration obtained during the study period, ionic components, OC and EC accounted for 45.3%, 19.7%, and 8.0%, respectively. $NO_3{^-}$ showed a unique seasonal distribution pattern due to a dependence on temperature and absolute humidity. It was estimated that an approximate temperature of $14^{\circ}C$, and absolute humidity of $7g/m^3$ were critical for the reversible reaction of $NH_4NO_3(p){\leftrightharpoons}NH_3(g)+HNO_3(g)$. The amount of OC and EC contributing to the monthly $PM_{2.5}$ mass concentration was higher in autumn and winter compared to spring and summer. This result could be attributed to the impact of burning biomass, since WSOC and the ratio of char-EC/soot-EC showed a similar pattern during the corresponding period. From the comparison of monthly WSOC/OC values, a maximum ratio of 83% was obtained in August (summer). The WSOC and estimated SOC levels derived from the EC tracer method correlated (R=0.77) in summer. The high occurrence of WSOC during summer was mainly due to the formation of SOC by photochemical reactions. Through long-term observation of $PM_{2.5}$ chemical components, we established that the degree to which the above-mentioned factors influence $PM_{2.5}$ composition, fluctuates with seasonal changes.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.324-327
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• 2002

For a next generation PET that realizes high sensitivity and high resolution, we proposed a design of a depth of interaction detector. A unit of the detector is constructed of four stages rectangular blocks of 2 by 2 Gd$_2$SiO$\sub$5/: Ce (GSO) crystal array optically coupled to position sensitive photomultiplier tube (PS-PMT). The 256ch flat panel PS-PMT is under development by Hamamatsu Photonics K.K., JAPAN. It has large cathode area, 51.7 by 51.7 mm$^2$, and the ratio of the effective area to external size is about 90%. The feature will contribute high packing fraction, accordingly high sensitivity. The 256 anodes are arranged in 16 by 16 at intervals of 3.0 mm. So as to evaluate the detector capability for identifying crystal of interaction, we got positioning image histograms with coupling a 16 by 5 array of GSO crystals, 2.9 by 2.9 by 7.5 mm$^3$, to the PS-PMT by irradiating a gamma ray uniformly from a point source. Flat panel PS-PMT is a new promising device for PET. We need to evaluate it if its performance is sufficiency. The performance was compared to the one with a 16ch PS-PMT.

• 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 Korean Library and Information Science Society
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• v.46 no.2
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• pp.203-225
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• 2015

This study was conducted in Tateyama, Japan with on-site observation conducted by Professor Aizawa, who organized this locality movement. This research was focused on listening to people's explanations, observations and studying the related documentation. First of all, the locality of Tateyama City was formed by utilizing the historic records of the area. Through Namo Amitabha which was carved on the four-sided stone pagoda, the city formed the locality as the peaceful city. "The gift of the Sea" painted by Shigeru Aoki in this city contributed to the identity of this locality known as the 'city of art which the painter loved'. The reconstruction of localities through the documentation of the relics are as follows. Satomi Castle, which was discovered to be the setting of the famous fictional saga Satomi and the Eight "Dogs". The excavation and research of the ruins of forgotten World War II, is another example of reconstruction at this locality. This locality is seen as 'the city of peace' and was reconstructed through a positive and future oriented attitude. It is noticeable that the locality of Tateyama city was newly formed or reconstructed using local records and documentation relics in the area.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• no.2
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• pp.171-177
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• 2004

This surveillance research drafted a conservation plan of regional green spaces, on a metropolitan area level, geared toward the Minuma Tanbo area of 1260 ha, located in Saitama City, in the suburbs of Tokyo. It was an effective method, applied to an area where Japan's current issues on regional green space were epitomized, as it formed symposiums consisting of various personnel, and the opinions of the citizen had been reflected.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.257-261
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• 1998

Two-dimensional wavelet spectrum analysis is applied to Advanced Very High Resolution Radiometer (AVHRR) images from the NOAA meteorological satellites in the area around Japan to unfold the horizontal structure of SST into space and scale (wavenumber), which can yield localized space-wavenumber information. The results reveal significantly new and previously unexplored insights on horizontal structure of sea surface temperature, which cannot be revealed using a traditional Fourier transform approach.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.349-352
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• 2007

The Fourth Assessment Report of IPCC predicted that global warming is already happening and it should be caused from the increase of greenhouse gases by the extension of human activities. These global changes will give a serious influence for human society. Global environment can be monitored by the earth observation using satellite. For the observation of global climate change and resolving the global warming process, satellite should be useful equipment and its detecting data contribute to social benefits effectively. JAXA (former NASDA) has made a new plan of the Global Change Observation Mission (GCOM) for monitoring of global environmental change. SGLI (Second Generation GLI) onboard GCOM-C (Climate) satellite, which is one of this mission, provides an optical sensor from Near-DV to TIR. Characteristic specifications of SGLI are as follows; 1) 250 m resolutions over land and area along the shore, 2) Three directional polarization observation (red and NIR), and 3) 500 m resolutions temperature over land and area along shore. These characteristics are useful in many fields of social benefits. For example, multi-angular observation and 250 m high frequency observation give new knowledge in monitoring of land vegetation. It is expected that land products with land aerosol information by polarization observation are improved remarkably. We are studying these possibilities by ground data and satellite data.

• The Journal of the Korea Contents Association
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• v.8 no.5
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• pp.237-245
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• 2008

Characteristics of Japanese public library recently has been changed to mutual networking between libraries, complex use of data, and long stay of users. Such change requires new service and contents. Also, in Korea, it is circumstance that interest of library's contents rise politically. And under government leading by BTL project, various libraries are increasing all over the country fast such as public library, extension of existing school library and the small library, etc. In this research, space composition of library, automatic check-out & bookshelf system, and mutual networking between libraries was analyzed by selected 3 libraries (central library of Chiba city, Tomisato and Ichigawa city library) of Chiba area and find applicable contents to our library system.