• School Mathematics
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• v.7 no.4
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• pp.427-444
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• 2005

The Purpose of this study is to explore he mathematical discovery and justification of six 10th grade students through mathematical modeling activities in spreadsheet environments. The students investigated problem situations with a spreadsheet, which seem to be difficult to solve in paper and pencil environment. In spreadsheet environments, it is easy for students to form a data table and graph by inputting and copying spreadsheet formulas, and to make change specific variable by making a scroll bar. In this study those functions of spreadsheet play an important role in discovery and justification of mathematical rules which underlie in the problem situations. In modeling activities, the students could solve the problem situations and find the mathematical rules by using those functions of spreadsheets. They used two types of trial and error strategies to find the rules. The first type was to insert rows between two adjacent rows and the second was to make scroll bars connecting specific variable and change the variable by moving he scroll bars. The spreadsheet environments also help students to justify their findings deductively and convince them that their findings are true by checking various cases of the Problem situations.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.1
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• pp.92-98
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• 1991

The structures such as railway bridges can be modelled as the multi-span beam on the elastic foundation. These structures are usually subject to the moving load, which has a great effect on dynamic stresses and can cause severe motions, especially at high velocities. In this paper, the dynamic responses of the multi-span beam on the elastic foundation were obtained by using the Galerkin's method and the numerical time integration technique. As trial functions, the same orthogonal polynomial functions obtained in part 1, were used. From the numerical results, it was found that the one term expansion of the assumed solution usually leads to the accurate solutions. However, in the case that the stiffness of the transnational spring is very high or the rotational spring is placed where the slope of the first mode is zero, the higher modes must be included to obtain the accurate solutions.

• Genomics & Informatics
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• v.4 no.3
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• pp.110-117
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• 2006

In microarray technology, many diverse experimental features can cause biases including RNA sources, microarray production or different platforms, diverse sample processing and various experiment protocols. These systematic effects cause a substantial obstacle in the analysis of microarray data. When such data sets derived from different experimental processes were used, the analysis result was almost inconsistent and it is not reliable. Therefore, one of the most pressing challenges in the microarray field is how to combine data that comes from two different groups. As the novel trial to integrate two data sets with batch effect, we simply applied standardization to microarray data before the significant gene selection. In the gene selection step, we used new defined measure that considers the distance between a gene and an ideal gene as well as the between-slide and within-slide variations. Also we discussed the association of biological functions and different expression patterns in selected discriminative gene set. As a result, we could confirm that batch effect was minimized by standardization and the selected genes from the standardized data included various expression pattems and the significant biological functions.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.3
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• pp.140-148
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• 1992

The free vibration problem of symmetrically laminated composite rectangular plates is formulated based on anisotropic thick plate theory including the effects of shear deformation and rotary inertia. Considering the difficulty of obtaining closed-form solutions, Rayleigh-Ritz analysis using polynomials having the property of Timoshenko beam functions as trial functions is adopted. The boundary conditions elastically restrained against rotation are accomodated as well as classical boundary conditions. From the results of numerical studies, the validity of the present method is verified. And it is also found that the adoption of thick plate theory for the vibration analysis of laminated composite plates is essential because of the relatively large shear deformation effect, and that the convergence of the Rayleigh quotient to the stationary value is less rapid in anisotropic composite plates than that in the orthotropic ones due to more complicated mode shapes of the former.

• Clinical Pain
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• v.19 no.1
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• pp.1-7
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• 2020

Objective: A prospective, assessor-blinded, randomized controlled trial was conducted in patients with chronic low back pain to evaluate the efficacy of portable low power laser therapy (LPLT) and the effect when combined with exercise therapy on pain and functions. Method: 60 patients were recruited and 56 patients, excluding 4 dropouts, were randomly allocated to the LPLT group (Group 1: 19 patients), placebo laser therapy with exercise group (Group 2: 18 patients), and LPLT with exercise group (Group 3: 19 patients). Laser therapy and exercise was performed five times a week for 4 weeks. Visual analogue scale (VAS), Schober test, lumbar range of motion (ROM) measures (flexion, extension and lateral flexion), Oswestry Disability index (ODI) were measured at baseline, at 4 weeks after intervention, and at 6 weeks after 2 weeks of no intervention. Results: Statistically significant improvements were noted in all group by time interaction with respect to all outcome parameters (p<0.05). All parameters in each group improved not only in the period of treatment (4 weeks), but also in the final evaluation (6 weeks) 2 weeks after the end of treatment. Post-hoc analysis showed statistically significant difference between the LPLT with exercise group and the other groups in all outcome parameters except for the ODI at 4 weeks and at 6 weeks. Conclusion: Portable LPLT is effective treatment in reducing pain and improving lumbar ROM and with exercise is more effective than laser or exercise monotherapy for the chronic low back pain patients.

• Journal of Physiology & Pathology in Korean Medicine
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• v.36 no.5
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• pp.169-174
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• 2022

In Korean medicine, the "five viscera" theory develops into the theory of homeostasis, in which the dynamic equilibrium state of the yin yang and five elements in the body maintain the balance of the physiological functions. The "five viscera" of the "five elements" can also be referred to as the "functional system," a conceptual system that includes all functional interactions mediated by the organ as well as the organ itself. Nowadays, the structure and function of the organs and tissues in the body are being re-examined, and there is now enough evidence that organs, structures, and their functions that belong to the same "element" are all connected in terms of energy metabolism. The functional system of the "kidney" includes the kidney itself, as well as other components that belong to "water" of the five elements such as bladder, bone, ear, essence, memory, and fear. The authors will discuss the latest findings in science and medicine to expand the understanding of the "Kidney" functional system to the level of molecular physiology.

• IMMUNE NETWORK
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• v.24 no.1
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• pp.9.1-9.21
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• 2024

The cytokine IL-7 plays critical and nonredundant roles in T cell immunity so that the abundance and availability of IL-7 act as key regulatory mechanisms in T cell immunity. Importantly, IL-7 is not produced by T cells themselves but primarily by non-lymphoid lineage stromal cells and epithelial cells that are limited in their numbers. Thus, T cells depend on cell extrinsic IL-7, and the amount of in vivo IL-7 is considered a major factor in maximizing and maintaining the number of T cells in peripheral tissues. Moreover, IL-7 provides metabolic cues and promotes the survival of both naïve and memory T cells. Thus, IL-7 is also essential for the functional fitness of T cells. In this regard, there has been an extensive effort trying to increase the protein abundance of IL-7 in vivo, with the aim to augment T cell immunity and harness T cell functions in anti-tumor responses. Such approaches started under experimental animal models, but they recently culminated into clinical studies, with striking effects in re-establishing T cell immunity in immunocompromised patients, as well as boosting anti-tumor effects. Depending on the design, glycosylation, and the structure of recombinantly engineered IL-7 proteins and their mimetics, recombinant IL-7 molecules have shown dramatic differences in their stability, efficacy, cellular effects, and overall immune functions. The current review is aimed to summarize the past and present efforts in the field that led to clinical trials, and to highlight the therapeutical significance of IL-7 biology as a master regulator of T cell immunity.

• Journal of Dairy Science and Biotechnology
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• v.42 no.2
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• pp.23-34
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• 2024

Milk, which is often referred to as a healthy beverage, is the first food encountered at birth. During digestion, A1-type milk often leads to digestive disorders due to increased levels of 𝛽-casomorphin-7. It also tends to induce inflammatory responses in the gut immune system by altering the gut microbiota and triggering conditions such as diabetes and respiratory hypersensitivity. In contrast, A2-type milk is gaining attention because of fewer associated problems than A1 milk and its unique functional benefits. However, information on the efficacy of A2 milk relies primarily on limited clinical and animal trial data, and substantiating its efficacy and functional superiority remains a challenge. Therefore, various studies, including research on the distinctive efficacy and functions of A2 milk compared with conventional A1 milk and investigations into the mechanisms underlying its effects on human health following consumption, are necessary in the future.

• Structural Engineering and Mechanics
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• v.39 no.6
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• pp.813-831
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• 2011

This paper presents an efficient version of Hilbert-Huang transform for nonlinear non-stationary systems analyses. An ensemble empirical mode decomposition (EEMD) is introduced to alleviate the problem of mode mixing between intrinsic mode functions (IMFs) decomposed by EMD. Yet the problem has not been fully resolved when a signal of a similar scale resides in different IMF components. Instead of using a trial and error method to select the "best" outcome generated by EEMD, a hybrid algorithm based on EEMD and EMD is proposed for multi-mode signal processing. The developed approach comprises the steps from a bandpass filter design for regrouping modes of the IMFs obtained from EEMD, to the mode extraction using EMD, and to the assessment of each mode in the marginal spectrum. A simulated two-mode signal is tested to demonstrate the efficiency and robustness of the approach, showing average relative errors all equal to 1.46% for various noise levels added to the signal. The developed approach is also applied to a real bridge structure, showing more reliable results than the pure EMD. Discussions on the mode determination are offered to explain the connection between modegrouping form on the one hand, and mode-grouping performance on the other.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.7
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• pp.634-642
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• 2004

Unlike actual vehicles, a vehicle driving simulator is limited in kinematic workspace and bounded on dynamic characteristics. So it is difficult to simulate dynamic motions of a multi-body vehicle model. In order to overcome these problems, a washout algorithm which controls the workspace of the simulator within the kinematic limitation is needed. However, a classical washout algorithm contains several problems such as generation of wrong sensation of motions by filters in tilt coordination, requirement of trial and error method in selecting the proper cut-off frequencies, difficulty in returning the simulator to its origin using only high pass filters and etc. This paper proposes a new tilt coordination method as an algorithm which gives more accurate sensations to drivers. In order to reduce time for returning the simulator to its origin, a new washout algorithm that the proposed algorithm selectively onset mode from high pass filters and return mode from error functions is proposed. As a result of this study, the results of the proposed algorithm are compared with the results of classical washout algorithm through the human perception models. Also, the performance of the suggested algorithm is evaluated by using human perception and sensibility of some drivers through experiments.