• Korean Journal of Soil Science and Fertilizer
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• v.37 no.6
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• pp.371-377
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• 2004

Sulfate adsorption in forest soils is a process of sulfur dynamics playing an important role in plant uptake, cation movement, acid neutralization capacity and so on. The relationship between sulfate adsorption and some physicochemical properties of four forest soils was investigated. Extractable sulfate contents and sulfate adsorption capacity (SAC) in the forest soils varied much among study sites. Extractable sulfate contents were more in sub-surface soils with lower organic matter and greater Al and Fe oxides than in surface soils. The average contents of $Al_d$ and $Fe_d$ in the sub-surface soils were 8.49 and $12.45g\;kg^{-1}$, respectively. Soil pH, cation exchange capacity and clay content were positively correlated with the extractable sulfate contents and SAC. Organic carbon content, however, was negatively correlated with the extractable sulfate contents, implying the competitive adsorption of sulfate with soil organic matter. Considerably significant correlation was found between inorganic + amorphous Al and Fe oxides and the sulfate adsorption, but crystalline Al and other fractions of Fe oxide showed no correlation. Relatively close relationship between the adsorbed sulfates and soil pH, cation exchange capacity, or amorphous Al oxides indicates that the accelerated soil acidification may substantially reduce the potential for sulfate adsorption contributing to sulfur flux in forest ecosystems.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.907-910
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• 1997

With increasing the needs for micro and precision parts, micro machining technology has been studied to fabricate a small part with high density such as electronics, optics, communications, and medicine industry more than before. But there are many problems to be solved requiring a high-level technology. So this research presents the new method to fabricate a small part through applying chemical mechanical micro machining (C3M) for the Al wafer. Al(thickness I ,u m) was sputtered on the Si substrate. Al is widely used as a lightweight material. However form defect such as burr has a bad effect on products. To improve machinability of ductile material, oxide layer was formed on the surface of AI wafcr before grooving by chemical reaction with HN03(10wt%). And then workpieces were machined to compare conventional micro-machining process with newly suggested method at different machining condition such as load and feed rate. To evaluate whether or not the machinability was improved by the effect of chemical condition, such as the size, the width of grooves 'and burr generation were measured. Finally, it is confirmed that C3M is one of the feasible tools for micro machining with the aid of effect of the chemical reaction.

• YAKHAK HOEJI
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• v.35 no.4
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• pp.319-325
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• 1991

Aluminum phosphate gel was synthesized by reacting aluminum sulfate as a soluble aluminum salt to tribasic sodium phosphate in this study. The optimal synthesis conditions based on the yield of product were investigated by applying Box-Wilson experimental design. It was found that optimal synthesis conditions were as follows: Reaction temperature; $61~71^{\circ}C$, concentration of two reactants; 12.27~13.83%, concentration ratio of two reactants; [AI$_{2}$(SO$_{4}$)$_{3}$]/[Na$_{3}$PO$_{4}$]= 0.5, reaction time; 10.9~12.1 minutes, drying temperature of product; $60~72^{\circ}C$. Aluminum phosphate gel prepared by the optimal synthesis conditions was suspended with four types of natural and synthetic gums at the concentration of 0.375~1.5wv%. Their Theological properties of aluminum phosphate gels were examined with Haake-Rotovisco RV 20 rotational viscometer. It showed that the higher concentration of suspending agents and lower temperature, the higher viscosity. Aluminum phosphate gel suspended by pectin and agar showed plastic flow with rheopexy, and their gels suspended by sodium alginate and sod. CMC showed plastic flow with thixotropy.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.635-638
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• 2002

In $ABCO_4$ and $ABC_3O_7$ (A=Ca, Sr; B=Y, Rare earth; C=Al, Ga), random distribution of static crystalline fields in activator sites results in inhomogeneous broadening of spectral lines of luminescent materials. In this study, we investigated luminescent properties of above-mentioned materials by excitation and emission spectra. In result, both $ABCO_4$:Tb and $ABC_3O_7$:Tb phosphors emit the green light. $ABC_3O_7$:Tb phosphors absorbed shorter wavelength energy than $ABCO_4$ phosphors so that the emission efficiencies of $ABC_3O_7$:Tb phosphors were higher than those of $ABCO_4$:Tb phosphors under vacuum UV.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.9
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• pp.443-448
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• 2002

The degradation characteristics of R, G, B phosphor layers in AC-PDP, which is due to the discharge of plasma, are still unknown. For the successful commercialization of AC-PDP, the degradation of phosphor layers, caused by the plasma discharge must be investigated and improved. In this paper, the degradation properties of phosphor layers in AC-$PDP_S$ are investigated. It takes long time to investigate the degradation in real condition, so that the device for accelerating the degradation is devised. To prove the performance of the device, the visible emission characteristics of phosphor layers and discharge with the environmental temperature are examined. As a result, it is shown that the phosphor layers are easily degraded when the discharge is sustained under high environmental temperature condition. After accelerating the degradation of blue Phosphor layer((Ba,Eu)Mg$AI_10$$O_17$) for 48 hours, its luminance decreases about 38 % and the corresponding color purity deteriorates severely.

• Journal of architectural history
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• v.3 no.1
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• pp.123-142
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• 1994

This paper is a part of "A Case Study on The Dwellings and Settlement of Korean Immigrants to North-Eastern Province of China". Among various subjects from the study, this paper covers with the spaces and life style in the dwellings of Korean Immigrants. The purpose of this paper is to discribe how their dwelling culture has been moved and changed to a new environment. One rural village of Korean Immigrants named "Ch'ang-ts'ai" in Yen-pien Province was selected where we investigated more than 110 households. From the formal interview, I collect the data on the family structure, family economic state, dwelling spaces and its use, and dwelling facillities and furniture. From informal interview with key informants, I analyze how they have changed their dwelling spaces and life style since they moved here. Based on the analysis of the data, I conclude that major features of their dwelling and life style has been moved from Korean penninsula, specially from 'Hamkyong' Province where their ancestor has lived. This features are summarized as follows: a. Dwelling spaces and its functions are simillar to typical dwelling type of Hamkyong Province. b. They use "Chong-ji" for both a cooking space and a major living space. c. They have a life style of sitting on the floor. d. Bedrooms are differentiated with male and female. e. Most of their dwelling facillities and furniture arc different from those of Chinese in the same province. Since they immigrated, there has been some social changes which could influence on making their dwelling culture. But they have preserved their cultural identity on their dwellings and life style. So I suggest that the dwelling culture of a society would be seldom changed by immigration, as long as they will be given similar conditions such as the independent ethnic community, the same ecosystem, and economical autonomy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.269-277
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• 2003

Effects of soy protein concentrate (SPC) containing isoflavone and casein diets on plasma phospholipid (PLs)-fatty acid patterns were investigated in 7-& 40- wk old female rats. Diets containing 16% SPC (soy/young:SY, soy/old: SO) and casein (casein/young : CY, casein/ old: CO) supplemented with 0.5% cholesterol were fed for 4 wks. Fatty acid compositions of plasma PLs were determined by TLC and GLC. Compared to the dietary protein effects, age effects on serum lipids were more profound. The levels of total cholesterol (Chol.), triglyceride, HDL-Chol., (LDL+VLDL)-Chol. and atherogenic index (AI) were higher in older groups (OC & OS) than younger groups (YC &. YS). Soy groups had higher Ell)L-Chol. level and lower (LDL+ VLDL)-Chol. and AI, compared with casein groups. The compositions of C22:0, Cl8:1 $\omega$9 and sum of MUFA in plasma PLs were significantly higher in casein group (CY & CO) than soy group (SY & SO), but those of sum of SFA were higher in soy group. The compositions of C22:0, Cl8:1 $\omega$9, C22:1, Cl8:3$\omega$3 and C22:4$\omega$6 were higher and those of C22:6$\omega$3, sum of $\omega$3, Cl8: 2$\omega$6 C20:4$\omega$6, sum of $\omega$6 and sum of PUFA were lower in plasma PLs of younger rats. The average P/S and $\omega$3/$\omega$6 ratio in older group was higher. The $\Delta$-7 desaturation index (16:0⇒16:1$\omega$7) and $\Delta$-9 desaturation index (18:0⇒18:1$\omega$9) were lower in soy group than casein group, while $\Delta$-6 and $\Delta$-5 desaturation index were not affected by dietary protein. The $\Delta$-4 desaturation index (22:4$\omega$6⇒22:5$\omega$6) were higher and elongation index (20:4$\omega$6⇒22:4$\omega$6) were lower in older group. The ratio of the products of $\omega$3 fatty acid series (Cl8:3) was significantly higher in older group, which indicated that age affected the plasma PUFA metabolism. On the other hand, older rats had higher serum cholesterol level compared with younger rats. Taken together, these changes in fatty acid composition might cause minimal changes in tile membrane fluidity induced by the increase serum cholesterol level.

• Journal of the Korea Convergence Society
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• v.12 no.12
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• pp.65-74
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• 2021

Recently, studies on Korean spelling correction have been actively conducted based on machine translation and automatic noise generation. These methods generate noise and use as train and data set. This has limitation in that it is difficult to accurately measure performance because it is unlikely that noise other than the noise used for learning is included in the test set In addition, there is no practical error type standard, so the type of error used in each study is different, making qualitative analysis difficult. This paper proposes new 'error type classification' for deep learning-based Korean spelling correction research, and error analysis perform on existing commercialized Korean spelling correctors (System A, B, C). As a result of analysis, it was found the three correction systems did not perform well in correcting other error types presented in this paper other than spacing, and hardly recognized errors in word order or tense.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.6
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• pp.850-858
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• 2022

To deploy Gate Recurrent Units (GRU) on resource-constrained embedded devices, this paper presents a reconfigurable FPGA-based GRU accelerator that enables structured compression. Firstly, a dense GRU model is significantly reduced in size by hybrid quantization and structured top-k pruning. Secondly, the energy consumption on external memory access is greatly reduced by the proposed reuse computing pattern. Finally, the accelerator can handle a structured sparse model that benefits from the algorithm-hardware co-design workflows. Moreover, inference tasks can be flexibly performed using all functional dimensions, sequence length, and number of layers. Implemented on the Intel DE1-SoC FPGA, the proposed accelerator achieves 45.01 GOPs in a structured sparse GRU network without batching. Compared to the implementation of CPU and GPU, low-cost FPGA accelerator achieves 57 and 30x improvements in latency, 300 and 23.44x improvements in energy efficiency, respectively. Thus, the proposed accelerator is utilized as an early study of real-time embedded applications, demonstrating the potential for further development in the future.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5371-5374
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• 2013

Objective: Photodynamic therapy (PDT) is an emerging therapeutic procedure suitable for the treatment of cervical cancer. However, the side effects of PDT are severe, including skin ulceration, so we designed an experiment to examine the effects of multiple low-dose photodynamic therapy of 5, 10, 15, 20-tetrakis(1-methylpyridinium-4-yl) porphyrin (Tmpyp4) on tumour growth by utilizing a model in nude mice implanted with Hela cervical cancer cells. Materials and Methods: Female BALB/c nude mice (aged 5-6 weeks, weighing 18-20 g) were used. Hela cervical cancer cells were injected subcutaneously ($1{\times}10^7cells/200{\mu}L$). Ten days after injection, the mice were divided into three groups (n=6), the A group of controls without any treatment, the B group receiving a single-treatment with Tmpyp4 (10 mg/kg, intratumor injection) and irradiation (blue laser, $108J/cm^2$), and the C group given three-treatments with Tmpyp4 (10 mg/kg, intratumor injection) and irradiation at intervals of two days. After starting treatment, tumours were measured every two days, to assess growth. At 2 weeks after the last treatment of C group, tumour tissue and organs were collected from each mouse to evaluate tumor histology and organ damage. Results: Tumour growth in C group was significantly inhibited compared with A and B groups (P<0.05), without any injury to the skin and internal organs. Conclusion: Our novel findings demonstrated that multiple low-dose photodynamic therapy of Tmpyp4 could inhibit cervical cancer growth significantly with no apparent side effects.