• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.7 s.349
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• pp.143-149
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• 2006

Turbo code, a kind of error correction coding technique, has been used in the field of digital mobile communication system. As the number of iterations increases, it can achieves remarkable BER performance over AWGN channel environment. However, if the number of iterations is increased in the several channel environments, any further iteration results in very little improvement, and requires much delay and computation in proportion to the number of iterations. To solve this problems, it is necessary to device an efficient criterion to stop the iteration process and prevent unnecessary delay and computation. In this paper, it proposes an efficient and simple criterion for stopping the iteration process in turbo decoding. By using sign changed ratio of extrinsic information values in turbo decoder, the proposed algorithm can largely reduce the average number of iterations without BER performance degradation. As a result of simulations, the average number of iterations is reduced by about $12.48%{\sim}22.22%$ compared to CE algorithm and about $20.43%{\sim}54.02%$ compared to SDR algorithm.

• The Journal of the Acoustical Society of Korea
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• v.15 no.2E
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• pp.39-44
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• 1996

The performance of two-channel adaptive noise canceller is ofter degraded by the weights perturbation due to the speech signal. In this paper, an adaptive noise canceller employing a speech detector and two adaptation algorithms which are switched according to the speech detector is proposed. When highly correlated speech signal is detected, the tap weights of the adaptive filter are adapted by the sign algorithm. On the other hand, the weights are adapted by the NLMS algorithm when silence is detected or when the characteristics of the noise propagation channel is changed. The employed speech detector utilizes the power ratio of the input and the output of an adaptive linear prediction-error filter. According to the computer simulation, the proposed method yields better performance than conventional ones.

• Biomolecules & Therapeutics
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• v.4 no.4
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• pp.415-418
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• 1996

This study was conducted to investigate the skin irritation toxicity of Syndella gel, a combination topical drug containing a deproteinised dialysate of calf's blood and micronomicin sulfate in the ratio of 20 to 1, in New Zealand White rabbits. In the primary skn irritation test with male New Zealand White rabbits, there was no treatment-related effect on clinical sign, nd body weight was not significantly changed. The Primary Irritation index (PII) was 0.33, indicating that Syndella gel was a mildly irritating formulation.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.6
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• pp.371-379
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• 2015

This study is purposed to seek the characteristics of both asbestos in accordance with acid and heat treatment for chrysotile and amosite used mainly as building materials. Results of acid treatment, the refractive index, the elongation sign, the extinction of acid-treated chrysotile were mostly similar to those of untreated chrysotile regardless of pH, elapsed time. But the characteristics of acid-treated chrysotile were different from those of untreated chrysotile after 8 weeks, at pH 1.2 acidic solution. When chrysotile treated with acid, weight ratio (%) of O and Mg fluctuated greatly in accordance with acid treatment unlike Si. But the change of constituents ratio (%) was small as time passed after acid treatment. The refractive index, the elongation sign and the extinction of acid-treated amosite were mostly similar to those of untreated amosite regardless of pH, elapsed time. When amosite was treated with acid, weight ratio (%) of Fe slightly increased. But in case of O, a contrary tendency was seen. Results of heat treatment, the higher the temperature, the more increased the refractive index of chrysotile. When chrysotile was heated for 10 minutes at $1,100^{\circ}C$, the elongation sign of chrysotile changed from positive(+) to negative(-). The extinction of chrysotile didn't change apparently in accordance with heat treatment. Also weight ratio (%) of O and Mg fluctuated greatly in accordance with heat treatment unlike Si. The higher the temperature, the more increased the refractive index of amosite. The elongation sign and the extinction of amosite didn't change apparently in accordance with heat treatment. Also weight ratio (%) of O and Fe fluctuated greatly in accordance with heat treatment. But weight ratio (%) of Si and Mg of heated amosite were mostly similar to those of untreated amosite regardless of temperature, heating time.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.6
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• pp.543-552
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• 2014

This research covers correlation analysis between the machine data measured from EPB Shield TBM construction site and the ground condition during excavation, and figures out how the machine data are affected by the change of ground conditions through single and mixed parameter analysis. It was found that when the ground is changed from hard rock to soft rock, the ratio of the cutter torque to thrust force increases. The relationship between the ratio of the cutter torque to thrust force and the penetration rate shows that the ratio has a certain range of values for hard rock; on the other hand, it increases for soft rock. It means that we can recognize a sign of appearance of weak zone by assessing the ratio of the cutter touque to thrust force according to each penetration rate. Multiple regression analysis of the machine data showed that the cutter torque increases with the increases of the total thrust force, and it decreases with the increase of the uniaxial compressive strength of the ground.

• Investigative Magnetic Resonance Imaging
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• v.20 no.4
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• pp.224-230
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• 2016

Purpose: The purpose of this study was to compare the grade of fatty degeneration and atrophy of rotator cuffs on immediate postoperative MRI to those on preoperative MRI in patients with rotator cuff tears. Materials and Methods: Seventy patients were included in this study, who received arthroscopic rotator-cuff repair and underwent both preoperative magnetic resonance imaging (MRI) and immediate postoperative MRI in our institution. Fatty degeneration of rotator cuffs and the atrophy of supraspinatus muscles were evaluated with T1 oblique sagittal images in the Y-shaped view. Fatty degeneration was evaluated using a Goutallier classification system, and the atrophy of supraspinatus muscles was evaluated using a modified tangent sign and a visual occupation ratio. Results: From 70 patients, a total of 100 tendons were repaired: 18, 69, and 13 tendons were treated for subscapularis, supraspinatus, and infraspinatus, respectively. The Goutallier grades (P = 0.012), modified tangent signs (P = 0.000), and visual occupation ratios (P = 0.000) of supraspinatus muscles were significantly decreased in immediate postoperative MRIs when compared to preoperative MRIs. In immediate postoperative MRIs, the Goutallier grades of supraspinatus muscles were decreased by one grade in 18.8% (n = 13) of the patients, and the atrophy of supraspinatus muscles was improved by one grade in 26.1% (n = 18) for modified tangent signs and 21.7% (n = 15) for visual occupation ratios. However, fatty infiltration by the Goutallier grades of subscapularis (P = 1.000) and infraspinatus (P = 0.157) muscles were not significantly changed after arthroscopic surgery. Conclusion: Immediate postoperative MRIs showed a significant improvement of fatty degeneration and muscle atrophy in supraspinatus muscles when compared to preoperative MRIs.

• Parasites, Hosts and Diseases
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• v.26 no.4
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• pp.229-238
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• 1988

In vitro culture of Toxoplasma gondii in HL-60 cells and cell-mediates immunity against Toxoplasma in dimethylsulfoxide(DMSO) -induced HL-60 cells, i.e., differentiation into granulocytes, were pursued. HL-60 calls were treated with various concentrations of DMSO, and 1.3%(v/v) for 3 day incubation was chosen as the optimal condition icy differentiation into granulocytes. The degree of differentiation was assayed in physiological and functional aspects in addition to morphological point. When treated with 1.3% DMSO for 3 days, HL-60 cells did not synthesiar DNA materials beyond background level, and showed active chemotactic response to chemotactic peptide, formal-methionyl-leucyl-phenylalanine(FMLP). Morphologically promyelocytes of high nuclearlcytoplasmic(NIC) ratio changed to granulocytes of relatively low WJC ratio. The relationships between HL-60 cells or DMSO-induced HL-60 cells and Toxoplasma were examined after stain with Giemsa and Buorescent dye (acridine orange). HL-60 cells did not show any sign of torso- plasmacidal activity but showed intracellular proliferation of Texoplasma to form rosette for 72 hr co-culture. In contrast, OMSO-induced HL-60 cells phagocytosed Toxoplasma within 1 hr, and performed a process of intracellular digestion of Toxoplasma thereafter. With the above results, it is suggested that phagosome-Iysosome fusion is one of the critical events for the parasitism by Toxoplasma or for susceptibility of host cells. The in vitro culture system of this study has offered a defined condition to study the protozoan parasite-host cell interactions.

• Journal of Korea Port Economic Association
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• v.37 no.4
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• pp.127-144
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• 2021

The purpose of this study is to derive service factors based on the "Rail Statistical Yearbook" data of railroad service providers from 1990 to 2019, and to analyze the effect of the service factors on the operating profit ratio(OPR), a representative management performance variable of railroad transport service providers. In particular, it has academic significance in terms of empirical research to evaluate whether the management innovation of the KoRail has changed in line with the purpose of establishing the corporation by dividing the research period into the first period (1990-2003) and the latter (2004-2019). The contents of this study investigated previous studies on the quality of railway passenger transportation service and analyzed the contents of government presentation data related to the management performance evaluation of the KoRail. As an empirical analysis model, a research model was constructed using OPR as a dependent variable and service factor variables of infrastructure, economy, safety, connectivity, and business diversity as explanatory variables based on the operation and management activity information during the analysis period 30 years. On the results of research analysis, OPR is that the infrastructure factor is improved by structural reform or efficiency improvement. And economic factors are the fact that operating profit ratio improves by reducing costs. The safety factor did not reveal the significant explanatory power of the regression coefficient, but the sign of influence was the same as the prediction. Connectivity factor reveals a influence on differences between first period and latter, but OPR impact direction is changed from negative in before to positive in late. This is an evironment in which connectivity is actually realized in later period. On diversity factor, there is no effect of investment share in subsidiaries and government subsidies on OPR.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.289-293
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• 2001

Objectives : The optimal treatment of craniopharyngioma is controversial. Despite recent advances in microsurgical management, complete surgical removal of craniopharyngioma remains very difficult. Radiation added to surgery is effective, but radiation therapy resulted in untoward side effect in young patient. Gamma knife radiosurgery offers the theoretical advantage of a reduced radiation dose to surrounding structures during the treatment of residual or recurrent craniopharyngioma compared with fractionated radiotheraphy. We described retrospective analysis of tumor size and clinical symptoms of patients after gamma knife radiosurgery in residual or recurrent craniopharyngioma were performed. Material and Methods : From September 1990 to January 2000, 18 patients of craniopharyngioma were treated by gamma knife radiosurgery. All patient had undergone surgery, but residual or recurrent tumor was found and all of them treated postoperative gamma knife radiosurgery. The mean age was 19(from 6 to 66) and male to female ratio was 10 to 8 and 8 patients were below 15 years old. In young age group(below age 15), the average volume of the tumor was $2904.8mm^3$ and mean maximal gamma knife dose was 34.9Gy. In old age group(older than 15), the average volume of the tumor was $2590.4mm^3$ and mean maximal gamma knife dose was 45.2Gy. The size of the tumor was average $2730.1mm^3$($88-12000mm^3$), mean average radiation dose was 40.7Gy and the mean prescription dose was 17.6 Gy(4-35Gy) delivered to a median prescription 50.7% isodose. Results : The follow up was from 1 year to 9 years(mean 59.1 months) after gamma knife radiosurgery. The tumor was controlled in 13(72.2%) patients. The tumor decreased in 9 patients and not changed in 4 patients. The tumor size increased in 4(22.2%) patients during follow up period. In two cases the tumor size increased because of its cystic portion was increased, but their solid portion of the tumor was not changed. In another two patients, the solid portion of the tumor was increased. So, one patient underwent reoperation and the other patient underwent operation and repeated gamma knife radiosurgery. The tumor recurred in one case(5.6%) that is a outside of irradiated site. The presenting symptoms were improved in 4 patients(improved visual acuity in 1, controlled increased intracranial presure sign in 3 patients). In one case, visual acuity decreased after gamma knife radiosurgery. The endocrine symptoms were not influenced by gamma knife radiosurgery. Conclusion : Craniopharyngioma can be treated successfully by gamma knife radiosurgery. Causes of the tumor regrowth are inadequate dose planning because of postoperatively poor margination of the tumor, close approximation of optic nerve and residual tumors outside the target lesion. Recurrence can develop 4 years after gamma knife radiosurgery. Volume is important, but the accurate targeting is more important to prevent tumor recurrence. If the tumor definition is not clear during planning gamma knife surgery, long-term image follow up is required.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.10 no.2
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• pp.145-157
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• 1999

This study was performed by the children and adolescents who were abused or neglected physically, emotionally that were selected in child & adolescents psychiatric ward. We investigated the number of these case in admitted children & adolescents, and also observed characteristics of symptoms, developmental history, characteristics of abuse style, characteristics of abusers, family dynamics and psychopathology. We hypothesized that all kinds of abuse will influnced to emotional, behavioral problems, developmental courses on victims, interactive effects on family dynamics and psychopathology. That subjects were 22 persons of victims who be determined by clinical observation and clinical note. The results of the study were as follows：1) Demographic characteristics of victims：ratio of sex was 1：6.3(male：female), mean age was $11.1{\pm}2.5$. According to birth order, lst was 12(54.5%), 2nd was 5(23%), 3rd was 2(9%) and only child was 3(13.5%). 2) Characteristics of family：According to socioeconomic status, middle to high class was 3(13.5%), middle one was 9(41.% ), middle to low one was 9(41%), low one was 1(0.5%). according to number of family, under the 3 person was 3(13.5%), 4-5 was 17(77.5%), 6-7 was 2(9%). according to marital status of parents, divorce or seperation were 5(23%), remarriage 2(9%), severe marital discord was 19(86.5%). In father, antisocial behavior was 7(32%), alcohol dependence was 10(45.5%). In mother, alcohol abuse was 5(23%), depression was 17(77.3%), history of psychiatric management was 6(27%). 3) Characteristics of abuse：Physical abuse was 18(81.8%), physical and emotional abuse and neglect were 4(18.2%). according to onset of abuse, before 3 years was 15(54.5%), 3-6 years was 5(27.5%), schooler was 1(15%). Only father offender was 2(19%), only mother offender was 8(35.4%), both offender was 8(35.4%), accompaning with spouse abuse was 7(27%), and accompaning with other sibling abuse was 4(18.2%). 4) General characteristics and developmental history of victims：Unwanted baby was 12(54.5%), developmental delay before abuse was9(41%), comorbid developmental disorder was 15(68%). there were 6(27.5%) who didn‘t show definite sign of developmental delay before abuse. 5) Main diagnosis and comorbid diagnosis：According to main diagnosis, conduct disorder 6(27.3%), borderline child 5(23%), depression4(18%), attention deficit hyperactivity disorder(ADHD) 4(18%), pervasive developmental disorder not otherwise specified 2(9%), selective mutism 1(5%). According to comorbid diagnosis, ADHD, borderline intelligence, mental retardation, learning disorder, developmental language disorder, oppositional defiant disorder, chronic tic disorder, functional enuresis and encoporesis, anxiety disorder, dissociative disorder, personality disorder due to medical condition. 5) Course of treatment：A mean duration of admission was $2.4{\pm}1.5$ months. 11(15%) showed improvement of symtoms, however 11(50%) was not changed of symtoms.