• Information Systems Review
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• v.25 no.1
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• pp.129-143
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• 2023

In the era of big data, the field of artificial intelligence is showing remarkable growth, and in particular, the image classification learning methods by deep learning are becoming an important area. Various studies have been actively conducted to further improve the performance of CNNs, which have been widely used in image classification, among which a representative method is the Convolutional Recurrent Neural Network (CRNN) algorithm. The CRNN algorithm consists of a combination of CNN for image classification and RNNs for recognizing time series elements. However, since the inputs used in the RNN area of CRNN are the flatten values extracted by applying the convolution and pooling technique to the image, pixel values in the same phase in the image appear in different order. And this makes it difficult to properly learn the sequence of arrangements in the image intended by the RNN. Therefore, this study aims to improve image classification performance by proposing a novel hybrid method of CNN and RNN applying the concepts of encoder and decoder. In this study, the effectiveness of the new hybrid method was verified through various experiments. This study has academic implications in that it broadens the applicability of encoder and decoder concepts, and the proposed method has advantages in terms of model learning time and infrastructure construction costs as it does not significantly increase complexity compared to conventional hybrid methods. In addition, this study has practical implications in that it presents the possibility of improving the quality of services provided in various fields that require accurate image classification.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.4
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• pp.412-419
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• 2024

Mn-doped Pb(In_1/2Nb_1/2)O₃-Pb(Mg_2/3Nb_1/3)O₃-PbTiO₃ (Mn:PIN-PMN-PT) single crystals, which exhibit improved phase transition temperatures and coercive field properties compared to Pb(In_1/2Nb_1/2)O₃-Pb(Mg_2/3Nb_1/3)O₃-PbTiO₃ (PIN-PMN-PT) single crystals, are expected to be utilized in high-power acoustic transducers. Bridgeman method, growing single crystals along the axial direction from melt, is most widely used method for single crystal growth with large size and high quality. However, single crystal boules grown by the Bridgeman method demonstrate a PT compositional variation, giving rise a distribution of crystal structure and material properties along the growing axis. To employ piezoelectric single crystals grown by the Bridgeman method for acoustic transducers, it is essential to investigate their overall property distribution. In this study, the compositional distribution and property variation of Mn:PIN-PMN-PT single crystals grown by the Bridgeman method was investigated. Measured compositional distribution of PT was from 29% to 32.5% in the Rhombohedral crystal region of the boule. Two types of specimen, [011]-poled Mn:PIN-PMN-29PT and Mn:PIN-PMN-32PT single crystals, were fabricated and tested to obtain full property variation at both ends of the Rhombohedral crystal region. The properties related to the 32 directional vibration mode and the properties related to high-power driving were measured to confirm the overall distribution of properties by composition.

• Geophysics and Geophysical Exploration
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• v.27 no.1
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• pp.37-50
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• 2024

The magnetotelluric (MT) survey can be affected by external environmental factors. In particular, when acquiring MT data in islands, it is essential to consider the combined effect of topography and sea to understand the results and make accurate interpretations. To analyze the MT response (apparent resistivity, phase) with consideration of the effect of topography and sea, a small cone-shaped island model surrounded by deep sea was created. Two-dimensional (2-D) and three-dimensional (3-D) forward modeling were performed on the terrain model considering topography and the island model considering both topography and sea. The 2-D MT response did not reflect the topographic and sea effect of the direction orthogonal to the 2-D profile. The 3-D MT response included topographic and sea effects in all directions. The XY and YX components of the apparent resistivity were separated on undulating topography, such as a hill. A conductor at 1 km below sea level could be distinguished from topographic and sea effects in the MT response, and low resistivity anomaly was attenuated at greater depths. This study will facilitate understanding of field data measured on small islands.

• Korean Journal of Construction Engineering and Management
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• v.25 no.2
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• pp.56-68
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• 2024

A construction standard production rates system for the factory built and on-site installation phases of OSC (Off-Site Construction)-based precast concrete (PC) structures in apartment buildings was recently proposed to establish an objective cost standard (Lee et al., 2021). In addition, the Korean government has taken steps to improve the institutional foundation for the systematic calculation of PC construction costs such as revising construction standard production rates for major components that can be applied to the on-site installation phase of PC method. In this study, we analyzed the results of a field survey of apartment building PC structures and collected expert opinions to develop factory-built and on-site installation standard production rates that can be applied to apartment building PC method. We also propose directions for improving the standard production rates so that they can be applied to the site and component of apartment buildings by comparing them with the current standard production rates. This study also derived the cost characteristics and cost reduction measures of PC construction by calculating the construction costs using the developed rates and comparing the construction costs with the RC methods of apartment buildings of the same scale. The construction standard production rates for PC construction derived in this study are expected to contribute to the spread of PC construction by ensuring the objectivity and consistency of the results of PC methods cost estimation.

• Investigative Magnetic Resonance Imaging
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• v.6 no.1
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• pp.64-72
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• 2002

Purpose : To introduce and demonstrate the advantages of the new hybrid two-dimensional (2D) proton spectroscopic imaging (SI) over the single voxel spectroscopy (SVS) and conventional 2D SI in the clinical application of spectroscopy for pediatric cerebral disease. Materials and Methods : Eighty-one hybrid 2D proton spectroscopic imaging was performed in 79 children (36 normal infants and children, 10 with hypoxic-ischemic injury, 20 with toxic-metabolic encephalopathy, seven with brain tumor, three with meningoencephalitis, one with neurofibromatosis, one with Sturge-Weber syndrome and one with lissencephaly) ranging in age from the third day of life to 15 years. In adult volunteers (n=5), all three techniques including hybrid 2D proton SI, SVS using PRESS sequence, and conventional 2D proton SI were performed. Both hybrid 2D proton SI and SVS using PRESS sequence were performed in clinical cases (n=). All measurements were performed with a 1.5-T scanner using standard head quadrature coil. The 16$\times$16 phase encoding steps were set on variable field of view (FOV) depending on the size of the brain. The hybrid volume of interest inside FOV was set as $75{\times}75{\times}15{\;}\textrm{mm}^3$ or smaller to get rid of unwanted fat signal. Point-resolved spectroscopy (TR/TE=1,500 msec/135 or 270msec) was employed with standard chemical shift selective saturation (CHESSI pulses for water suppression. The acquisition time and spectral quality of hybrid 2D proton SI were compared with those of SVS and conventional 2D proton SI. Results : The hybrid 2D proton SI was successfully conducted upon all patients.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.171-181
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• 1999

A field experiments was carried out to investigate the physicochemical properties of soil and cucumber growth in vinyl house when irrigation point was made at 0.2, 1/3, 0.5 and 1.0 bar. The obtained results was summarized as follow: The taxonomic class of the soil used was loam and each content of the required water was 4.4, 7.3, 9.6 and 13.4 mm per each irrigation time at 0.2, 1/3, 0.5 and 1.0 bar treatments in spring culture, respectively. At 0.2 bar and 1.0 bar treatments, interval of irrigation was 2.3 and 14.8 day, the times of irrigation was 37 and 6, and total irrigation volume was 163.5 and 80.3 mm, respectively. After cucumber culture, pH, EC concentration and exchangeable K content of soil at 0.2 bar treatment was distributed near to the level of improvement target while EC, available $P_2O_5$ and exchangeable base content in other treatments were higher compared to improvement target. At 1.0 bar treatment, ratios of the solid and liquid phase were 44.9 and 27.1%, respectively, and bulk density was $1.26g\;cm^{-3}$ which was the highest among the treatments. At 0.2 bar treatment, the ratio of the solid and liquid phase was 41.7 and 22.8%, respectively, and bulk density was $1.09g\;cm^{-3}$ which was the lowest. The root length and radius at 0.2 bar treatment were best, while those at 1/3 bar were worst. At 0.2 bar treatment, the total yield was 7,269 kg and the weight of good products was 5,677 kg which was the highest among treatments. At 0.33 bar treatment, the yield was the lowest with the high ratio of deformity.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1157-1163
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• 2012

This study was performed a comparative life cycle assessment (LCA) among three rice production systems in order to analyze the difference of greenhouse gases (GHGs) emissions and environment impacts. Its life cycle inventory (LCI) database (DB) was established using data obtained from interview with conventional, without agricultural chemical and organic farming at Gunsan and Iksan, Jeonbuk province in 2011. According to the result of LCI analysis, $CO_2$ was mostly emitted from fertilizer production process and rice cropping phase. $CH_4$ and $N_2O$ were almost emitted from rice cultivation phase. The value of carbon footprint to produce 1 kg rice (unhulled) on conventional rice production system was 1.01E+00 kg $CO_2$-eq. $kg^{-1}$ and it was the highest value among three rice production systems. The value of carbon footprints on without agricultural chemical and organic rice production systems were 5.37E-01 $CO_2$-eq. $kg^{-1}$ and 6.58E-01 $CO_2$-eq. $kg^{-1}$, respectively. Without agricultural chemical rice production system whose input amount was the smallest had the lowest value of carbon footprint. Although the yield of rice from organic farming was the lowest, its value of carbon footprint less than that of conventional farming. Because there is no compound fertilizer inputs in organic farming. Compound fertilizer production and methane emission during rice cultivation were the main factor to GHGs emission in conventional and without agricultural chemical rice production systems. In organic rice production system, the main factors to GHGs emission were using fossil fuel on machine operation and methane emission from rice paddy field.

• Journal of Korean Medical classics
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• v.11 no.2
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• pp.114-134
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• 1998

The conception of pyo(標) bon(本) joong(中) in the part of woongihak(運氣學) of negeong(內徑) one of the important thing that decides the relation between six gi(六氣) and samyum and samyang(三陰三陽) or between each other's of samyum and samyang itself, it says that the relation of Pyo-rce(表裏). So this conception from the ancient times have been used to explain the theory of meridian(經絡) and organs(五臟六腑) and in other important field of oriental medicine - Sanghannon(傷寒論), it became basis of explanation of pcthoiogical principles in the system of six kyung(六徑). At first, the subject or this study is limited to the rament of $\ll$Somun(素問)$\gg$ in order to find the accurate and original meanings of pyo(標) bon(本) joong(中). And the meanings are studied by the way of expanding it's meaning with basic conceptions of woongihak(運氣學) and astronomy included in negeong(內徑). In this study, the results are summarized as the followings. 1. The contents of - the 68th chapter of negeong(內徑), concerning pyo(標) and joong(中) come under chogi(初氣) and joonggi(中氣) of the same chapter, after consideration of astronomical knowledge. And they become active during the period that last about 30days, a haft of one step(一步) of kaekgi(客氣). 2. Bon(本) as a kind of six gi(六氣) that is revealed from internal principle of something, that is to say Ohhaeng(五行), comes mainly under the kaekgi(客氣) of woongihak(運氣學) with the meaning of 'sign' is thai the specific properties of six gi(六氣) are revealed to our sight, so we can feel that through the change of nature, Joong(中) is the other property hidden in the inside of six gi(六氣), that is a portion of original nature(本性) like the bon(本). 3. The relation of pyo(標) and bon(本) is like that bctween the principle hidden inside in all things(理) and it's expression into the real world(氣) also similar to thai of yumyang(陰陽) and ohhaeng(五行). Therefore bon(本), though it means one of the six gi(六氣), hale the property of ohhaeng(五行) and pyo(標) is revealed, with an appearance of samyum-samyang(三陰三陰). 4. pyo(標) and joong(中) are also the both sides of yum(陰) and yang(陰) that revealed under the change of yumyang-ohhaengl(陰陽五行) in the nature. For example, if the one is yang(陰), the other is yum(陰). In the process that the change of all things is revealed out, first the property of pyo(標) appears strongly and then that of joong(中) appears comparatively weakly. But, in spite of the inhibitive relation of yumyang(陰陽), pyo(標) and joong(中) promote each other. 5. Under the course of change. It happens according to the bon(本), the property of ohhaeng(五行) in the case of soyang(少陽) and taeyum(太陰), because the effect of moisture(濕) and fire(火) that makes hyung(形) and gi(氣) is very strong in the universe. In the case of taeyang(太陽) and soyum(少陰), it happens according to the bon(本) and pyo(標) because they hare the polarity of water and fire(火水), at the same time, are not separated each other. In the case of yangmeong(陽明) and gualyum(厥陰), the change appears only according to the joong(中), but not strongly because the phase of yangmeong(陽明) and gualyum(厥陰) is a lull phase processing to the next one.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.421-430
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• 2004

The purpose of this study was to measure and compare the amount of unreacted TEGDMA from pit and fissure sealants cured with three different light sources; conventional halogen light curing unit, plasma arc light curing unit and argon laser. The specimens were eluted in distilled water for different time intervals. The time-related release of TEGDMA were analyzed by reverse-phase high performance liquid chromatography(HPLC). The result of present study can be summarized as follows: 1. The time-related release of TEGDMA decreased with increasing curing time in conventional halogen light, however, that not statistically significant difference(p>0.05). 2. The elution from the specimens cured for 6 and 9 seconds with plasma arc light was similar results corresponding with the time-related TEGBMA release, and was significantly lower than that cured for 3 seconds(p<0.05). 3. The elution of TEGDMA from the specimens cured with argon laser was significantly higher than that cured with halogen and plasma arc light(p<0.05). 4. The elution of TEGDMA from under recommended time of three different light sources were showed to be no statistically significant difference(p>0.05). 5. In time-related release of TEGDMA from recommended time of each light sources, the results correspond to 40 seconds of halogen light and 6 seconds of plasma arc light were similar(p>0.05). 6. The elution of TEGDMA, from over recommended time of three different light sources were showed to be no statistically significant difference(p>0.05). In this study, I suggest that curing time of plasma arc light is 6 and/or 9 seconds in the field of clinical pediatric dentistry claiming its effectiveness in optimal polymerization and reduced chair time.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.963-974
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• 2015

This study was conducted to determine the effects of organic vegetable cultivation on the soil physical properties in 33 farmlands under plastic greenhouse in Korea. We were investigated 5~8 farms per organic vegetable crops during the period from August to November 2014. The main cultivated vegetables were leafy lettuce (Lactuca sativa L.), Perilla leaves (Perilla frutescens var. Japonica Hara), cucumber (Cucumis sativus L.), strawberry (Fragaria ananassa L.) and tomato (Lycopersicon spp.). We have analyzed soil physical properties. The measured soil physical parameters were soil plough layer, soil hardness, penetration resistance, three soil phase, bulk density and Porosity. The measurement of the soil plough layer, soil hardness and penetration resistance were carried out direct in the fields, and the samples for other parameters were taken using the soil core method with approximately 20 mm diameter core collected from each organic vegetable field. Soil plough layer was average 36 cm and ranged between 30 and 50 cm, and slightly different depending on the sorts of vegetable cultivation. The soil hardness was $0.17{\pm}0.15{\sim}1.34{\pm}1.02$ in the topsoil, $0.55{\pm}0.34{\sim}1.15{\pm}0.62$ in the subsoil. It was not different between topsoil and subsoil, but showed a statistically significant difference between the leafy and fruit vegetables. Penetrometer resistance is one of the important soil physical properties that can determine both root elongation and yield. The increase in density under leafy vegetables resulted in a higher soil penetrometer resistance. Soil is a three-component system comprised of solid, liquid, and gas phases distributed in a complex geometry that creates large solidliquid, liquid-gas, and gas-solid interfacial areas. The three soil phases were dynamic and typically changed in organic vegetable soils under greenhouse. Porosity was characterized as range of $54.2{\pm}2.2{\sim}60.3{\pm}2.4%$. Most measured soils have bulk densities between 1.0 and $1.6gcm^{-3}$. To summarize the above results, Soil plough layer has been deepened in organic vegetable cultivation soils. Solid hardness (the hardness of the soil) and bulk density (suitable for the soil unit mass) have been lowered. Porosity (soil spatial content) was high such as a well known in organic farmlands. Important changes were observed in the physical properties according to the different vegetable cultivation. We have demonstrated that the physical properties of organic cultivated soils under plastic greenhouse were improved in the results of this study.