• Composites Research
• /
• v.31 no.2
• /
• pp.51-56
• /
• 2018

A new study was carried out to utilize a pencil drawing paper sensor (PDPS), which drew a line using a pencil on the paper, as a sensor. The sensing effect on 3 different papers based on the properties of PDPS was compared. The specimens were prepared by drawing 4B pencils on plain (A4), Hwasun, and Han papers. The silver paste was used to give good electrical contacts of the copper wires and the pencil drawn line. The chemical structures of 3 papers for PDPS by FT-IR spectrum analysis were similar and the comparative compact states of each paper were observed by optical microscope. From statistical evaluation of tensile strength using 3 papers, plain paper was chosen to be best for the PDPD. The optimum drawing number of PDPD was determined by changing the thickness of the paper with the drawing number. Electrical resistance (ER) with graphite on 3 different papers were compared. The changes in compression was observed through cyclic compressive test of composite materials, it was possible to predict the degree of strain sensing under compressive test. It leads to expectation of properties.

• The Journal of Korean Society for Radiation Therapy
• /
• v.14 no.1
• /
• pp.79-84
• /
• 2002

The main cause factor for effective the output, especially in small & irregular shaped field of electron beam therapy, are collimation system, insert block diameter and energy. In the absorption deose of treatment fields, we should consider the lateral build-up ratio (LBR), which the ratio of dose at a point at depth for a given circular field to the dose at the same point for a 'broad-field', for the same incident fluence and profile. The LBR data for a small circular field are used to extract radial spread of the pencil beam, ${\sigma}$, as a function of depth and energy. It's based on elementary pencil beam. We consider availability of the factor, ${\sigma}$, in the small & irregular fields electron beam treatment.

• Composites Research
• /
• v.33 no.4
• /
• pp.228-233
• /
• 2020

In this paper, a single lap shear test was performed using a glass fiber reinforced composite material (GFRC). Pencil lead drawn paper sensor (PLDPS) was applied for single lap shear test being performed. Bisphenol-A epoxy and amine hardener were used as adhesives combining with composite materials. To make a difference in adhesive properties, the adhesive was cured under different conditions. PLDPS was made of a 4B pencil on A4 paper. Because graphite in a pencil was an electrically conductive substance, electric resistance (ER) could be measured. A change in ER was observed by a position where a PLDPS was attached to single lap shear specimens. It was confirmed that the change in ER was different depending on two attached positions and was observed by lap shear strain as well. In case the lap shear strain was large, the change in ER of PLDPS was high. This was because the larger the extension of the adhesive part, the larger the degree of bending of the specimen and thus the larger the distance change between two electrodes.

• Korean Chemical Engineering Research
• /
• v.62 no.2
• /
• pp.147-152
• /
• 2024

Most medical sensors are disposable products. In order to reduce inspection and diagnosis costs, it is more important to develop the inexpensive electrode materials. We fabricated the CuO NPs/PANI/E-PGE as an electrode material for disposable electrochemical sensors and applied it to a non-enzymatic glucose sensor. For surface activation of PGE, pretreatment was performed using chemical and electrochemical methods, respectively. Electrochemical properties according to the pretreatment method were analyzed through chronoamperometry (CA), cyclic voltammetry (CV) and electrochemical impedance (EIS). From these analytical results, the electrochemically pretreated PGE (E-PGE) was finally adopted. The non-enzymatic glucose sensor based on CuO NPs/PANI/E-PGE shows sensitivity of 239.18 mA/mM×cm² (in a linear range of 0.282~2.112 mM) and 36.99 mA/mM×cm² (3.75423~50 mM), detection limit of 17.6 μM and good selectivity. Based on the results of this study, it was confirmed that the modified PGE is a high-performance electrode material. Therefore, these electrodes can be applied to a variety of disposable sensors.

• Journal of The Korean Association For Science Education
• /
• v.28 no.1
• /
• pp.32-46
• /
• 2008

The purpose of this study was to analyse the qualitative and quantitative characteristics of paper-pencil tests for exploring its appropriateness as a selection tool of the gifted in science. For this purpose, we developed two (internal and external) item analysis frameworks, and applied these frameworks to analyse qualitative characteristics. Also, we analysed the relationship between two characteristics. The results of analysing qualitative characteristics revealed that the portion of items with acceleration context exceeding middle school curriculum level was relatively large, which caused low content validity. Furthermore, there was considerable deviation in content and context by subject matter and year, which caused test unstability. Items measuring knowledge domain was the most prevalent, and too much weight on data interpretation & analysis domain in inquiry process skills. In case of creativity test, the portion of items measuring convergent thinking was much larger than that of divergent or associative thinking. Most of these items were represented by using pictures and tables rather than using graphs. Item types of multiple-choice and short answers were superior to essay types. Discrimination index, on the whole, was appropriate (above 0.3), but item difficulty showed a vast deviation ($0.01{\sim}0.90$). Correlation coefficients among subject matters and test tools were very low, and test reliabilities were also low. Low item difficulty & high discrimination index item types were distinguishable. Items with acceleration context were more discriminating than enrichment context. Implications of developing quality paper-pencil test items in the selection of gifted students are discussed.

• Journal of the Korean Mathematical Society
• /
• v.37 no.5
• /
• pp.871-884
• /
• 2000

Polyharmonic operator with Dirichlet boundary condition is considered in a n-dimensional cone. The regularity properties of weak solutions are studied. In particular, it is proved the Holder contionuity of solutions near the vertex of the cone for dimensions n=2m+3,2m+4, where 2m is the order of the polyharmonic operator.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2000.11a
• /
• pp.163-166
• /
• 2000

This paper presents an image processing algorithm which gives an sketch effect on the real image taken by CCD camera. The essence of the technique is the expression of shading by the line touch. Several line patterns are developed to emulate pencil drawings, fusains, Indian ink paintings. This algorithm is expected to be used for computer portraits, character development, and souvenirs.

• Journal of Korean Academy of Nursing
• /
• v.39 no.6
• /
• pp.781-787
• /
• 2009

Purpose: The purpose of this study was to evaluate a computerized touch-screen version of the asthma-specific quality-of-life (cA-QOL) questionnaire against the conventional paper-and-pencil version (pA-QOL) for equivalence, time for completion, user preference, and ease of use. Methods: A total of 261 patients were recruited. A randomized cross-over design was used. Patients in group A completed the cA-QOL first while waiting to see a physician, and completed the pAQOL version after seeing the physician. Patients allocated in group B completed these questionnaires in the reverse order. The patients were asked questions about user preference and ease of use of the cA-QOL. The time taken to complete both versions of the questionnaire was measured. Results: Weighted kappa coefficients of all items showed almost perfect agreement. The time required to complete the pA-QOL is faster than the time for cA-QOL. The patients who preferred the cA-QOL were 37.5%, while those who preferred the pA-QOL were 29.9%. Most patients reported that the cA-QOL was "easy" or "very easy" to complete. Conclusion: The cA-QOL is the computerized equivalent of the pA-QOL. The findings herein demonstrate that the cA-QOL can be helpful to nurses in busy practices for assessing, collecting, and evaluating their patients' health related quality of life.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.24 no.4 s.175
• /
• pp.1024-1031
• /
• 2000

The plate waves propagating in thin plates have dispersive nature showing the dependence of velocities on the frequency. Wavelet transform (WT) using Gabor function can be used to analyze the dispersive waves in the time-frequency domain, and then to find the arrival time of the waves propagating in the plate. Plate waves in the aluminum plate of 3 mm thickness were identified and generated by pencil lead breaks and the lowest order symmetric ($S_o$) and antisymmetric ($A_o$) modes were analyzed by the WT method. The measured group velocities agreed very well with theoretical predictions in the frequency range of 50-400 kHz. The pencil breaks were also used to simulate acoustic emission sources in the plate, and the source location algorithm using the wavelet transform of dispersive plate waves was found to give accurate results.

• Journal of The Korean Association of Information Education
• /
• v.11 no.2
• /
• pp.147-155
• /
• 2007

Paper & pencil test provides limited informations about student. So many web-based computerized test systems are developed and tried. But These systems have drawbacks that cannot visit previous or next problems freely. So These systems cannot get deep informations such as elapsed time of each problem, history of answer modification, the number of visit time of each problem. These deep informations are very important in educational evaluation area. Therefore we develop educational evaluation system can get these deep informations including basic informations. And then we apply paper & pencil test and our system to 67 students, and execute survey. The reason of survey is to ascertain availabilty of our system.