• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.6
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• pp.115-121
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• 2013

This paper related with the DSE-MMA (Dithered Sign-Error MMA) that is the simplification of computational arithmetic number in blind equalization algorithm in order to compensates the intersymbol interference which occurs the passing the nonlinear communication channel in the presence of the band limit and phase distortion. The SE-MMA algorithm has a merit of H/W implementation for the possible to reduction of computational arithmetic number using the 1 bit quantizer in stead of multiplication in the updating the equalizer tap weight. But it degradates the overall blind equalization algorithm performance by the information loss at the quantization process compare to the MMA. The DSE-MMA which implements the dithered signed-error concepts by using the dither signal before qualtization are added to MMA, then the improved SNR performance which represents the roburstness of equalization algorithm are obtained. It has a concurrently compensation capability of the amplitude and phase distortion due to intersymbol interference like as the SE-MMA and MMA algorithm. The paper uses the equalizer output signal, residual isi, MD, MSE learning curve and SER curve for the performance index of blind equalization algorithm, and the computer simulation were performed in order to compare the SE-MMA and DSE-MMA applying the same performance index. As a result of simulation, the DSE-MMA can improving the roburstness and the value of every performance index after steady state than the SE-MMA, and confirmed that the DSE-MMA has slow convergence speed which meaning the reaching the seady state from initial state of adaptive equalization filter.

• Journal of the Korean Geotechnical Society
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• v.31 no.8
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• pp.17-28
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• 2015

The purpose of this study is to measure the volumetric water content of unsaturated soils during drying and wetting process by using volumetric pressure plate extractor (VPPE) incorporated with time domain reflectometry (TDR). The VPPE consists of a pressure cell, a pressure regulator, a burette system and a TDR probe. Two samples with different initial void ratios were prepared in the pressure cell, and the air pressure at the range of 0.1 kPa - 50 kPa was applied to adjust the matric suction by the pressure regulator. The burette system was used to measure the volumetric water content change of the sample according to the matric suction. In addition, the TDR probe, installed in the cell, was used to evaluate the dielectric constant from the reflected signal of the electromagnetic wave at the probe. The volumetric water content of specimen was estimated by the empirical equation between the volumetric water content and dielectric constant, which was calibrated with the Jumunjin sand. The test results show that the volumetric water content calculated by TDR probe is strongly correlated to the measured value by burette system. The hysteresis occurs during drying and wetting process. Furthermore, the degree of hysteresis reduces in the repeated process. This study suggests that TDR may be effectively used to evaluate the water content soil for the determination of water characteristic curve of unsaturated soils.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9C
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• pp.868-875
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• 2003

In this paper, enhanced multiresolution motion estimation(MRME) using reduction of one-pixel shift in wavelet domain is proposed. Conventional multiresolution motion estimation using hierarchical relationship of wavelet coefficient has difficulty for accurate motion estimation due to shift-variant property by decimation process of the wavelet transform. Therefore, to overcome shift-variant property of wavelet coefficient, two level wavelet transform is performed. In order too reduce one-pixel shift on low band signal, S$_4$ band is interpolated by inserting average value. Secondly, one level wavelet transform is applied to the interpolated S$_4$ band. To estimate initial motion vector, block matching algorithm is applied to low band signal S$_{8}$. Multiresolution motion estimation is performed at the rest subbands in low level. According to the experimental results, proposed method showed 1-2dB improvement of PSNR performance at the same bit rate as well as subjective quality compared with the conventional multiresolution motion estimation(MRME) methods and full-search block matching in wavelet domain.

• Korean Journal of Clinical Pharmacy
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• v.22 no.4
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• pp.330-339
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• 2012

Background : Hypertension is treated with both lifestyle modification and pharmacotherapy. The Seventh Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC-7), published in 2003, provides a streamlined management approach to hypertension for the primary care physician. The JNC-7 is the gold standard also in Korea. According to the JNC-7, special therapeutic considerations are recommended for high-risk individuals with compelling indications. The presence of compelling indications in any given patient should be considered when selecting specific pharmacotherapy to treat hypertension. However, in patients with compelling indications, it is unknown that hepatotoxicity is caused by Calcium Channel Blocker (CCB), one of 1st anti-hypertensive drugs. Now, the CCB is the most used 1st anti-hypertensive drug in Korea Therefore, we evaluated the changes in blood liver function parameters (ALT, AST, Total bilirubin, serum albumin) for the study group. Methods : We randomly collected and retrospectively analyzed Electronic Medical Record data (n=28,788) of patients, and who took calcium channel blockers(non-dihydropyridines; diltiazem, verapamil, dihydropyridines; amlodipine, barnidipine, benidipine, clinidipine, efonidipine, felodipine, isradipine, lacidipine, lercanidipine, nicardipine, nifedipine, nimodipine), with having liver function tests (LFTs) from July 1st 2009 to June 30th 2010 at the Seoul National University Hospital in Korea. Control groups are two antihypertensive agents: RAS blockade (ARB; candesartan, irbesartan, losartan, olmesartan, telmisartan, valsartan, ACE-I; cilazapril, enalapril, fosinopril, imidapril, perindopril, ramipril) and, Diuretics (loop; furosemide, torsemide, thiazide; hydrochlorothiazide[HCTZ], indapamide). Patients not having LFT results at these three standard points of time(baseline, during, medication, and after finishing medication) were excluded. The collected data were analyzed by using the SPSS (Version12.0) and Microsoft Excel (Version2007). Results : 711 patients who were treated CCB (297), RAS blockade (232) or Diuretics (182) monotherapy were selected for the study. In selected patients, liver damage degree(changes of each LFTs value) was higher in diuretics group than other groups, followed by RAS blockade and CCB. In diuretics group's was loop-diuretics group was higher than thiazide-diuretics group. In CCB group, Nondihydropyridine-CCB's damage degree was higher than Dihydropyrine-CCB's that. Conclusions : Despite the limitations due to the retrospective study, among patients with abnormal LFTs, the use of CCBs led to a less liver damage than other 1st anti-hypertensive agents. It can be recommended CCBs as one of the initial treatments of hypertension in patients with liver disease.

• Journal of the Korea Concrete Institute
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• v.19 no.3
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• pp.367-375
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• 2007

Critical chloride content for corrosion initiation is a crucial parameter in determining the durability and integrity of reinforced concrete structures, however, the value is still ambiguous. Most of the studies reporting critical threshold chloride content have involved the experimental measurement of the average amount of the total chloride content at arbitrary time. The majority of these researches have not dealt with this issue combined with carbonation of concrete, although carbonation can significantly impact on critical threshold chloride content. Furthermore, the studies have tried to define the critical chloride content within the scope of their experimental concrete mix proportion at arbitrary time. However, critical chloride content for corrosion initiation is known to be affected by a lot of factors including cement content, type of binder, chloride binding, concentration of hydroxyl ions, and so on. It is necessary to define the unified formulation to express the critical chloride content for various mix proportions of concrete. The purpose of this study is to establish an analytical formulation of the critical chloride content of concrete. In this formulation, affecting factors, such as mix proportion, environment, chemical evolution of pore solution with elapsed time, carbonation of concrete and so on are taken into account. Based on the Gouda's experimental results, critical chloride content is defined as a function of $[Cl^-]$ vs. $[OH^-]$ in pore solution. This is expressed as free chloride content with mass unit to consider time evolution of $[OH^-]$ content in pore solution using the numerical simulation programme of cementitious materials, HYMOSTRUC. The result was compared with other experimental studies and various codes. It is believed that the approach suggested in this study can provide a good solution to determine the reasonable critical chloride content with original source of chloride ions, for example, marine sand at initial time, and sea water penetration later on.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.5
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• pp.606-616
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• 2006

Purpose: This experiment examined the effect of different surface treatment on the osseointegration and stability of implants. Material and methods: In this study, 40 each of machined, SLA and RBM implants, which are the most commonly used implants, were implanted into the tibia of 20 normal rabbits using $OsseoCare^{TM}$. The rabbits were sacrificed after 1 week, 4 weeks, 8 weeks and 12 weeks for implant stability analysis, removal torque analysis, histologic and histomorphometric analysis. Result : ISQ showed significant difference between Machined and RBM at first week and at 4 weeks. There was significant difference between Machined and both SLA and RBM(p<0.05) but after 8 weeks there were no significant difference between each group. In the removal torque, RBM showd significantly higher values than SLA and Machined surface at 1st week. At 4th and 12th week, there was significant difference between Machined and SLA, RBM(p<0.05). In the bone to implant contact variable, there was no significant difference between each surface treatment method. In the Machined surface group, there was no significant difference between each time interval. but in SLA group, there were significant differences between the 1st week and 12th week and in RBM group, there were significant differences between the 1st week and 8th, 12th week and between 4th and 12th week(p<0.05). The bone area showed significantly higher values in SLA and RBM compared to Machined surface 1st and 8th week and significantly higher values in SLA than Machined surface at the 4th week(p<0.05). Conclusion: The roughened surface of implants showed positive effect in the early stages of implantation and assisted in bone formation After the bone formation stage, there was no statistical difference between Machined and roughened surface groups. In dental implantation, where initial stability is critical to the success of implants, the use of roughened surface implants should assist in reducing the healing period after implantation.

• Journal of the Korean Electrochemical Society
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• v.10 no.3
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• pp.213-218
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• 2007

In order to find out proper PVdF gel polymer electrolyte for Li/S battery, we investigated PVdF gel polymer electrolytes with various glyme type plasticizer such as polyglyme, tetraglyme, triglyme. The organic solvents as triglyme, tetraglyme, polyglyme (Mn = 250, 500) has different chain length of ethylene oxide(EO) in solvent of glyme system. ionic conductivity decreased as increasing chain length of EO in plasticizers. Ionic conductivity of PVdF gel electrolyte with tetraglyme, triglyme, polyglyme (Mn = 250, 500) at room temperature was $5{\times}10^{-4},\;3{\times}10^{-4},\;6{\times}10^{-5},\;3{\times}10^{-5}\;S/cm$, respectively. Li/S cell with PVdF gel polymer electrolyte using tetraglyme plasticizer had low interfacial resistance and the highest initial discharge capacity of 1232 mAh/g of active sulfur, which was about 70% utilization of theoretical value.

• Tuberculosis and Respiratory Diseases
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• v.40 no.1
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• pp.72-78
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• 1993

Background: In malignancies, detection of metastatic foci is of value in making therapeutic plans for treatment of disease and prevention of life-threatening complications. Common sites for metastasis of bronchogenic cancer include lymph nodes, liver, brain, adrenals and bone. Skull, vertebrae, ribs and long bones are common sites for bone metastasis. But in epidermoid carcinoma, the incidence of bone metastasis is relatively low and especially to the distal phalangeal bone is rare. Methods: We experienced a case of epidermoid carcinoma with the first distant metastasis to the fifth distal phalangeal bone, right toe. Results: The initial stage in the diagnosis of epidermoid carcinoma was T4N3MO. During the third round of anticancer chemotherapy, we recognized the distant metastasis to the fifth distal phalangeal bone for the first time. Localized abnormal findings were noted by bone X-ray and scanning. By a histopathologic examination of the amputated toe, we confirmed the metastasis of epidrmoid bronchogenic carcinoma. Conclusion: If localized abnormal finding is discovered at an unusual site for metastasis, we recommend physicians to consider the possibility of metastasis even though it is very low.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.88-91
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• 2002

The two dimensional size effect of specimen gauge section (length x width) was investigated on the compressive behavior of a T300/924 [45/-45/0/90]3s, carbon fiber-epoxy laminate. A modified ICSTM compression test fixture was used together with an anti-buckling device to test 3mm thick specimens with a 30$\times$30, 50$\times$50, 70$\times$70, and 90mm$\times$90mm gauge length by width section. In all cases failure was sudden and occurred mainly within the gauge length. Post failure examination suggests that $0^{\circ}$ fiber microbuckling is the critical damage mechanism that causes final failure. This is the matrix dominated failure mode and its triggering depends very much on initial fiber waviness. It is suggested that manufacturing process and quality may play a significant role in determining the compressive strength. When the anti-buckling device was used on specimens, it was showed that the compressive strength with the device was slightly greater than that without the device due to surface friction between the specimen and the device by pretoque in bolts of the device. In the analysis result on influence of the anti-buckling device using the finite element method, it was found that the compressive strength with the anti-buckling device by loaded bolts was about 7% higher than actual compressive strength. Additionally, compressive tests on specimen with an open hole were performed. The local stress concentration arising from the hole dominates the strength of the laminate rather than the stresses in the bulk of the material. It is observed that the remote failure stress decreases with increasing hole size and specimen width but is generally well above the value one might predict from the elastic stress concentration factor. This suggests that the material is not ideally brittle and some stress relief occurs around the hole. X-ray radiography reveals that damage in the form of fiber microbuckling and delamination initiates at the edge of the hole at approximately 80% of the failure load and extends stably under increasing load before becoming unstable at a critical length of 2-3mm (depends on specimen geometry). This damage growth and failure are analysed by a linear cohesive zone model. Using the independently measured laminate parameters of unnotched compressive strength and in-plane fracture toughness the model predicts successfully the notched strength as a function of hole size and width.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.271-282
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• 1982

The browning development, mainly through the Maillard reaction, occurring in the dried fish meat products during storage causes reduction of the nutritional value due to the loss of the essential amino acid such as available lysine as well as off -flavor resulting in the deterioration of the food quality thus shortening the shelflife. In the work, the changes in the amount of available lysine, extractable nitrogenous compounds (nonprotein-N, amino-N, trimethylamine oxide, trimethylamine, and free lysine) and development of browning were measured to assess the relationship between the shelflife and the quality loss in dried filefish under the steady state conditions (35,45, and $55^{\circ}C;a_{w}'s$ of 0.44 0.52, 0.65 and 0.75 at each temperature) and fluctuating temperature condition of $35/55^{\circ}C$ will. alternating 7 day periods at each water activity. The results indicated that the amount of available lysine and extractable nitrogenous compounds except TMA decreased rapidly with increasing temperatures and water activities while the rate of available lysine and extractable nitrogenous compounds must be involved in the initial stage of brown pigment formation. The available lysine loss of the dried filefish products stored under the fluctuating temperature conditions was greater than that stored under its fixed mean temperature, $45^{\circ}C$. The activation energies for lysine loss obtained from the Arrhenius plot ranged 6.9 to 4.4 Kcal/mol and $Q_{10}$ values at $40^{\circ}C$ were 1.4 to 1.2. The values for browning were 15.7 to 14.4 Kcal/mol and 2.2 to 2.0 respectively. Shelf-life, defined as the time to reach 0.15 O. D./g solid or the limit of off-color deterioration by browning reaction, was extented longer than the halflife of Iysine loss, actually corresponding $75\%$ loss of available lysine. This suggested that the halflife of lysine loss might not be adequate to assess the shelf-life of the food system with high potential of protein, nonproteinous nitrogen compounds, and lipids.