• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.317-321
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• 2006

The investigation of the formation of organic sulfur compounds (i.e., odor species), mainly methyl mercaptan and demethyl suifide, during kraft pulping has been conducted, in which both hardwood and softwood species were used. It was discovered that there is an organic sulfur compounds formation phase transition point with respect to delignification extent. The transition point occurs at a kappa number of approximately 35 and 20 for softwoods and hardwoods, respectively. The results also showed that both low sulfidity and anthraquinone (AQ) addition are helpful to control the formation of theses organic sulfur compounds during kraft pulping. Whereas Hexenuronic acid (HexA) has contribution to Kappa number, the extended delignification not only lead to low pulp yield, but also be adverse to odor control. A significant in-digester odor reduction can be achieved if the pulping is to be terminated before phase transition point and combined with AQ addition.

• Physical Therapy Rehabilitation Science
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• v.3 no.2
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• pp.142-147
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• 2014

Objective: This study aims to investigate high energy and low energy extracorporeal shockwave therapy (ESWT) and which one is more effective for shoulder pain. Design: Single blind randomized controlled trial. Methods: Fifty two subjects with upper trapezius (UT) trigger point (TrP) participated in this study. They were allocated to high energy (n=26) and low energy group (n=26). This study applies ESWT and investigates the changes of pressure pain threshold (PPT) and visual analogue scale (VAS). The high and low energy groups received focused piezo electric type ESWT 4 Hz, 1,000 pulses and 0.351 and $0.092mJ/mm^2$ respectively. Outcome measures of PPT and pain was measured by algometer and pain VAS. These measurements were performed before and after treatment. Results: The PPT value was significantly increased in both groups after treatment (p<0.05) and VAS scores were significantly decreased after treatment in both groups (p<0.05). However, there were no significant differences between groups. Conclusions: ESWT is an effective treatment for the application of the UT TrP. Although there were significant effects of extracorporeal shock wave therapy on PPT and VAS scores, there were no signficant differences between high and low energy extracorporeal shock wave therapy.

• Journal of Korean Clinical Health Science
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• v.3 no.3
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• pp.399-408
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• 2015

Objective. There were two objectives of the study, first was to identify the barriers as perceived by the patients and providers to access the low vision services and second was to identify the challenges faced by the main providers. Study design. Structured questionnaire based interviews of patients and providers Methodology. To find out the barriers to access of low vision services, the interviews based on structured questionnaire were conducted for two patient groups. The first group consisted of 97 visually impaired individuals attending the department of low vision services at Al-Shifa Trust Eye Hospital Rawalpindi while the second group included 56 visually impaired individuals attending the four rehabilitation centers/schools for the blind in Rawalpindi/Islamabad. To identify the barriers as perceived by the main providers of low vision services and challenges faced by them the interviews based on structured questionnaire were conducted for 19 low vision service providers. Results. From patients point of view, major barrier to low vision services identified was inability to visit hospital /rehabilitation center alone - 29.8% in hospital group and 33.9% in rehabilitation centers group, while the lack of social support, lack of family support, cost of travelling, long distance, afford ability, hesitation in using devices and lack of satisfaction were other important barriers identified. From providers' point of view, major barrier to uptake of services was the need for repeated follow-ups. Optometrists were the main provider of low vision services contributing to 47.4% of the providers. The major challenge faced by the providers was motivation of patients to use low vision devices. Conclusion. The major barrier to low vision services according to the patients is inability to visit the hospital alone, while according to providers, it is the need for repeated follow up which proves major barrier towards uptake of services. The motivation is the major challenge faced by providers, majority of which are optometrists.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.14
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• pp.5937-5940
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• 2014

Background: This study was conducted as a descriptive-correlational exercise with the aim of determining the effect of student perceptions of social skills on their pro and con perceptions of smoking. Materials and Methods: The study sample comprised 106 students at $6^{th}$, $7^{th}$ and $8^{th}$ grades in three primary schools. The data were collected through socio-demographic data collection form, Social Skill Perception Form and Child Decisional Balance Scale. Data were evaluated by percentage calculation, Student t test and correlation analysis. Results: While the point average of pro perception of smoking of the students with a high point average of social skill perception, was $8.6{\pm}3.1$, in those with a low social skill perception point average it was $10.7{\pm}4.2$, the difference being significant(p=0.012). The respective point averages of con perceptions were $26.8{\pm}3.7$ and $23.5{\pm}3.3$, again significant (p=0.000). While a positive medium level (r=0.410) relationship was determined between the point average of social skill perception and con perception of smoking, a negative low level (r=0.281) relationship was determined with the pro perception of smoking. Conclusions: As the social skill perception point average increases, children's con perceptions of smoking increase and their pro perceptions decrease.

• Journal of Technology Innovation
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• v.14 no.1
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• pp.147-175
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• 2006

One of the biggest problems of Korean economy is polarization of firms for export and domestic demand and that of conglomerates and SME's achievement. One of the culprits lies weakness of intermediate industry such as machine tool. Since intermediate industry is important path where export performance affects domestic demand and whose actor usually is SMEs with high spill over effect in labor market. Especially, intermediate industry Is vulnerable because of industrial policy biased In backward linkage effect. However if a country fails to develop intermediate industry above some critical point, that country would fall in low-tech equilibrium without growth. In case of benign circle where final goods industry growth leads growth of intermediate industry and again it leads that of final goods industry, it can reach high-tech equilibrium. By contrast, in opposite case where in industrialization latecomer fails to link industries likewise above some critical point that country would fall in low-tech equilibrium without growth. Moreover, for several reasons, machine tool firms of Korea have difficulty in catching up technology above critical point. Firstly. Conglomerate demander neglects their product. Secondly, even after success of development overcoming difficulties they fail to get market share for response of dumping of foreign competitors. And the last one is patent litigation of foreign competitors that incapacitate the technology development. For these, Korean machine tool firms fell in 'middle-income country trap' itself, since they stuck in some extent when they technologically catch up. Consequently, for latecomer country in machine tool industry to leapfrog meaningfully policy support is necessary, Weak intermediate industry does not Induce domestic firms and remained fragile. Therefore, localization, policy should reflect condition of technological catch up more than before, in order to be effective and fruitful. There should be turning point over relationship between conglomerates, major demander of machine tool and SME's, for only with active purchasing of conglomerate Korean machine industry can grow.

• Investigative Magnetic Resonance Imaging
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• v.15 no.1
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• pp.57-66
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• 2011

Purpose : A new inhomogeneity correction method based on two-point Dixon sequence is proposed to obtain water and fat images at 0.35T, low field magnetic resonance imaging (MRI) system. Materials and Methods : Joint phase-magnitude density function (JPMF) is obtained from the in-phase and out-of-phase images by the two-point Dixon method. The range of the water signal is adjusted from the JPMF, and 3D inhomogeneity map is obtained from the phase of corresponding water volume. The 3D inhomogeneity map is used to correct the inhomogeneity field iteratively. Results : The proposed water-fat imaging method was successfully applied to various organs. The proposed 3D inhomogeneity correction algorithm provides good performances in overall multi-slice images. Conclusion : The proposed water-fat separation method using JPMF is robust to field inhomogeneity. Three dimensional inhomogeneity map and the iterative inhomogeneity correction algorithm improve water and fat imaging substantially.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.673-676
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• 2009

Non-point pollutants, which mainly originate from high traffic roads and rural areas, contaminate the environment by flowing into various rivers and lakes and thus are of interest as an environmental issue. Accordingly, efforts have been made to design and maintain efficient filter systems for the control of the non-point pollutants. Meanwhile, clay-type materials are widely used for the absorption of chemicals included in pollutants and the absorption performances of various clays have been reported in the literature. Thus, the present study proposes a non-destructive monitoring method for the performance of a clay-type filter using electrical resistivity measurement. A series of experimental tests is performed on celite-based particulate filters with infiltrating non-point source pollutants having the same characteristics as pollutants on high traffic roads. Each test measures permeability, resistivity of the filter materials and resistivity of the filtrated water. As the particulate filter materials filtrate pollutants and absorb heavy chemicals (e.g., $Cr^{6+}$, lead, nickel, among others), ionic concentration increases resulting as the electrical resistivity decrease. When the filter systems approach the end of their lifetime, the electrical resistivity of the filter material converges to a very low value due to lowered filter absorption efficiency. Hence, the electrical resistivity of the filtrated water also converges to a low value due to high concentrations of heavy metals. The permeability converges to a very low value because of significantly reduced porosity due to clogging and absorption of pollutants on the filter material. The experimental results show that electrical resistivity monitoring of filter materials is a promising approach to estimation of filter performance and its life expectancy.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.9
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• pp.777-781
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• 2001

This paper presents an image contrast enhancement technique for improving the low contrast images using the improved IAFC(Integrated Adaptive Fuzzy Clustering) model. The low pictorial information of a low contrast image is due to the vagueness or fuzziness of the multivalued levels of brightness rather than randomness. Fuzzy image processing has three main stages, namely, image fuzzification, modification of membership values, and image defuzzification. Using a new model of automatic crossover point selection, optimal crossover point is selected automatically. The problem of crossover point selection can be considered as the two-category classification problem. The improved IAFC model is used to classify the image into two classes. The proposed method is applied to several experimental images with 256 gray levels and the results are compared with those of the histogram equalization technique. We utilized the index of fuzziness as a measure of image quality. The results show that the proposed method is better than the histogram equalization technique.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1867-1875
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• 2011

In this paper, a low-area 256-point FFT structure is proposed. For low-area implementation CSD(Canonic Signed Digit) multiplier method is chosen. Because multiplication type should be less for efficient CSD multiplier application to the FFT structure, the Radix-$4^2$ algorithm is chosen for those purposes. After, in the proposed structure, the number of multiplication type is minimized in each multiplication block, the CSD multipliers are applied for implementation of multiplication. Furthermore, in CSD multiplier implementation, cell-area is more reduced through common sub-expression sharing(CSS). The Verilog-HDL coding result shows 29.9% cell area reduction in the complex multiplication part and 12.54% cell area reduction in overall 256-point FFT structure comparison with those of the conventional structure.

• Journal of Auto-vehicle Safety Association
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• v.14 no.2
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• pp.39-44
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• 2022

This paper presents LiDAR static obstacle map based vehicle position correction algorithm for urban autonomous driving. Real Time Kinematic (RTK) GPS is commonly used in highway automated vehicle systems. For urban automated vehicle systems, RTK GPS have some trouble in shaded area. Therefore, this paper represents a method to estimate the position of the host vehicle using AVM camera, front camera, LiDAR and low-cost GPS based on Extended Kalman Filter (EKF). Static obstacle map (STOM) is constructed only with static object based on Bayesian rule. To run the algorithm, HD map and Static obstacle reference map (STORM) must be prepared in advance. STORM is constructed by accumulating and voxelizing the static obstacle map (STOM). The algorithm consists of three main process. The first process is to acquire sensor data from low-cost GPS, AVM camera, front camera, and LiDAR. Second, low-cost GPS data is used to define initial point. Third, AVM camera, front camera, LiDAR point cloud matching to HD map and STORM is conducted using Normal Distribution Transformation (NDT) method. Third, position of the host vehicle position is corrected based on the Extended Kalman Filter (EKF).The proposed algorithm is implemented in the Linux Robot Operating System (ROS) environment and showed better performance than only lane-detection algorithm. It is expected to be more robust and accurate than raw lidar point cloud matching algorithm in autonomous driving.