• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.4
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• pp.415-421
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• 2015

This paper describes the study of the design procedure for the step-by-step setup parameters and of the magnetizing method for performance and size reduction in the development of a haptic vibrator. The study of magnetization was accomplished by comparing the electromagnetic force in accordance with the horizontal and the vertical magnetization. The theoretical results indicated that the horizontal magnetization resulted in a better performance. The systematic design of a step-by-step procedure for establishing the design parameters was verified by testing the characteristics of the fabricated prototype product. The vibration response function analysis and electric field analysis were processed by decoupling of the analytical method, and these were determined to be in good agreement with the test results. The design parameters to contributing to the product reliability included the spring height, the welding position, and the coil position. The sensitivity of the electromagnetic field and the performance change were analyzed based on the design parameters. As a result, we proposed a design method to implement a reliability-based, high performance haptic vibrator.

• Journal of Energy Engineering
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• v.18 no.1
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• pp.56-62
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• 2009

With weld metal of X65 steel, hydrogen was charged by electro-chemical method and mechanical behavior such as strength was measured by the small punch test. The weld metal was more sensitive to hydrogen charging than the case of base metal. The small punch (SP) strength was decreased as the hydrogen contents increased. Magnitude of strength decrease was dependent on current density, temperature, charging time. Current density and charging time have significant effect on the mechanical properties but temperature of electrolyte has limited effect. Fractured surfaces of the tested specimens were observed by SEM (scanning electron microscope). In the hydrogen charged specimens cleavage fracture were observed, which is consistent with the SP test results. Since the testing procedure for studying hydrogen embrittlement proposed in this study has shown good reproducibility of test results, the proposed method can be assumed to be a reliable test procedure. Using the electrochemical charging and the small punch test, the change of SP strength for X65 weld metal due to hydrogen embritlement could be evaluated sensitively.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.5 no.2
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• pp.313-323
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• 1998

This study was a descriptive research on the level of self-care available to continous ambulatory peritoneal dialysis patients (hereinafter referred to as 'CAPD patient') related to the specific area of infection management. The method employed for the collection of data was a modified instrument of the self-care survey essentially based on Young Sook Choi's instrument. The relevant data was collected from september 1, 1996 to september 30, 1996. The subjects were provided with an open-ended question regarding the reasons behind why they did not seek self-care. The answers provided about self-care compliance were analyzed by SPSS for frequency, percentage, mean, t-test, ANOVA. Reasons for non-compliance were analyzed by content analysis. The results of the study were as follows : 1. The percentage of patients engaging in self-care were according to the following self performed tasks : preparation of dialysis : 30.58 points Dialysate exchange procedures : 49.40 points - Two bag type : 50.50 points - Spike type : 48.80 points - Neo type : 48.90 points Catheter exit site care : 25.13 points More specifically, in relation to the preparation of dialysis as referred to above, those patients engaging in self care was relatively high with respect to the cleaning of the dialysis before use and for the preservation of peritosol. However, in dialysate exchange procedures, data revealed that those patients engaging in self-care are relatively low with respect to putting on a mask during the performance of peritosol exchange. Similary in peritosol exchange procedure and catheter exit care, low levels of self-care performance were found in the area of putting on a mask during the peritosol exchange procedures and catheter line testing procedures, respectively. 2. In general characteristics, there appeared to be no distinction in self-care compliance among CAPD patients. 3. The main reasons for non-compliance were based in the following factor : intellectual, attitude, enviromental surrounding and physical. As a result of the foregoing finding, nurses should provide adequate assistance to promote self-care compliance by CAPD patients by checking the preparation of dialysis, dialysate exchange procedure, and catheter exit site care which recieved low point in this research.

• Science of Emotion and Sensibility
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• v.19 no.4
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• pp.95-110
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• 2016

The purpose of this study was to propose a proper method for the multilevel mediation analysis, for which the hierarchical method should be utilized, then MLM (multilevel modeling) approach as a hierarchical method has been popularly utilized until MSEM (multilevel structural equation modeling) approach was not proposed. This purpose was covered by three research questions about statistical methods, analytic procedure, and real example. First, MSEM statistical method was preferred to MLM method for its estimation accuracy and analytic flexibility. Second, the four-step procedures of model building, assumption examination, model comparison, and coefficient testing were proposed for the multilevel mediation analysis. Third, the real data of 2695 students of elementary and secondary schools and 89 teachers were analyzed in the multilevel directions of $2{\rightarrow}2{\rightarrow}1$ and $1{\rightarrow}1{\rightarrow}2$. Out of these directions of $2{\rightarrow}2{\rightarrow}1$, and $1{\rightarrow}1{\rightarrow}2$ model, only the coefficient of $2{\rightarrow}2{\rightarrow}1$ model was significant at the 95% CI. Mplus programs used for the real example are attached on the Appendix. Based on the results, significance and limitations of this study, were discussed in detail.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.6
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• pp.25-34
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• 2012

New calibration method for the near-field scanning (NFS) system is presented. The proposed calibration method consisted of a new near-field antenna (NFP) and newly devised patterns as circular patch patterns (CPPs) and meander patterns (MPs). The proposed patterns were used for improving spatial resolutions and simplifying a calibration procedure of the NFP compared to the conventional method defined in the IEC61967-3 and 6. Also, the effect of the length of NFPs on attenuation characteristics was investigated with length of 8mm and 30mm. For them, we designed and fabricated CPPs of diameter (D) = 20, 40, 60, and 100mm and MPs of various widths and spaces. We found the reverse relations between spatial resolutions and heights of measuring points by using simplified calibration procedure. The testing result shows that the spatial resolution of $120{\mu}m$ at height of $200{\mu}m$ was verified without complex correlation algorithms under 8GHz. For manufacturing cost all patterns and the NFP were realized with low-cost fabrication using PCB (FR-4) not by a conventional LTCC process. For verification of chip-level EMC from the results, near-field scanning system (NFSS) having step resolution of Sub-micron scale was produced and by using the proposed NFSS and proposed NFP measurement of chip shows accurately the shape of the resolution of $200{\mu}m$ patterns for securing a high level of chip-level EMC verification.

• Journal of Food Hygiene and Safety
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• v.38 no.3
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• pp.89-98
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• 2023

Currently, no guidelines exist regarding the maximum residues of pesticides in edible oil which is a processed food commonly consumed in Korea. This lack of guidelines hinders the evaluation of the safety of edible oil in terms of pesticide contamination. In this study, an analysis method based on heat distillation and GC-MS/MS was established by optimizing the extraction and purification procedure for 68 pesticides. Important variables in the thermal distillation procedure included heating temperature and time, and we found the nitrogen flow rate as a mobile phase and the type of dissolving solvent were not considerably affected. The determination coefficient (R²) of the residual pesticide was 0.99 or higher, and the quantitative limit (LOQ) was 0.01-0.02 mg/L. The average recovery rate (n=5) was 66.1-120.0% and the relative standard deviation was lower than ±10% when 68 pesticides were spiked at concentrations of 0.01-0.02, 0.1, and 0.5 mg/L. In addition, the within-laboratory precision was less than ±11%, meeting the Korea Food and Drug Safety Evaluation Institute's Guidelines on Standard Procedures for Preparing Food Testing Methods (2016). Therefore, the test method developed in this study can be used as a test method for managing the safety of the residual pesticide concentration in edible oil.

• Journal of radiological science and technology
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• v.26 no.4
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• pp.27-32
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• 2003

To evaluate usefulness of a functional tracheobronchial phantom for interventional procedure. The functional phantom was made as a actual size with human normal anatomy used silicone and a paper clay mold. A tracheobronchial-shape clay mold was placed inside a square box and liquid silicone was poured. After the silicone was formed, the clay was removed. We measured film density and tracheobronchial angle at the human, animal and phantom, respectively. The film density of trachea part were 0.76(${\pm}0.011$) in human, 0.97(${\pm}0.015$) in animal, 0.45(${\pm}0.016$) in phantom. The tracheobronchial bifurcation part measured 0.51(${\pm}0.006$) in human, 0.65(${\pm}0.005$) in animal, 0.65(${\pm}0.008$) in phantom. The right bronchus part measured 0.14(${\pm}0.008$) in human, 0.59(${\pm}0.014$) in animal and 0.04(${\pm}0.007$) in phantom. The left bronchus were 0.54(${\pm}0.004$) in human, 0.54(${\pm}0.008$) in animal and 0.08(${\pm}0.008$) in phantom. At the stent part were 0.54(${\pm}0.004$) in human, 0.59(${\pm}0.011$) in animal and 0.04(${\pm}0.007$) in phantom, respectively. The tracheobronchial angle of the left bronchus site were $42.6({\pm}2.07)^{\circ}$ in human, $43.4({\pm}2.40)^{\circ}$ in animal and $35({\pm}2.00)^{\circ}$ in phantom, respectively. The right bronchus site were $32.8({\pm}2.77)^{\circ}$ in human, $34.6({\pm}1.94)^{\circ}$ in animal and $50.2({\pm}1.30)^{\circ}$ in phantom, respectively. The phantom was useful for in-vitro testing of tracheobronchial interventional procedure, since it was easy to reproduce.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.1
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• pp.71-81
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• 1987

To fuly utilize the availability of the ISDN, it is very important to develop the ISDN user terminals which can provide various user services. In this paper, the basic concept of the ISDN user terminal is briefly studied and, based on this study, a stimulus type digital telephone which can be connected directly to the ISDN is designed. This digital telephone can provide the basic voice service and has general functions such as voice encoding / decoding(PCM is used), user-network signalling, digital tone supply, channel selection, key pad and atatus display. Echo cancellation method is adopted for the digital subscirber loop transmission and user-network signalling is implemented according to the LAPD(Link Access Procedure on D-channel) protocol recommended by the CCITT's recommendations I.440-I.441. The validity of designed S/W and H/W functions are verified by testing them with ISDN circuit switching emulator described in the first part of this paper.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.80-82
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• 2012

다양한 정보보호 제품이 개발됨에 따라, 정보보호 제품 보증을 위해 자체의 보안성 평가 및 인증이 중요시되고 있다. 정보보호 제품의 평가 및 인증을 위해서는 보안기능 검사와 취약점 분석 단계가 매우 중요하지만 이를 위한 정보보호 제품의 보안기능 시험과 취약성 분석을 위한 테스팅 절차에 대한 연구는 그 중요성에 비해 많이 수행되지 않았다. 현재까지는 보안제품을 기능별로 제품을 분류하여 보안성을 평가하였는데, 본 논문에서는 보안 제품들에서 공격에 취약한 SW 모듈 중심으로 테스팅 대상을 분류하는 방법을 제안한다. 분류된 SW 모듈별로 적합한 보안 테스팅 기법을 정의하고, 보안제품의 취약점을 효과적으로 탐지하기 위해 공개되어 있는 관련 취약점도 분석하였다. 이를 통해 정보보호 제품의 취약점 분석 및 제품 보안성 평가를 위한 SW 모듈별 보안 테스팅 절차를 수립하고, 테스트하였다. 실험을 통해 취약한 SW 모듈별 적절한 공격 기법 선정 시 제안 절차가 정보보호 제품 평가 인증에 활용될 수 있음을 확인하였다.

• Annals of Clinical Neurophysiology
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• v.10 no.2
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• pp.83-97
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• 2008

Cervical and thoracic radiculopathies are among the most common causes of neck pain. The most common causes are cervical disc herniation and cervical spondylosis in patients with cervical radiculopathy, and diabetes mellitus and thoracic disc herniation in thoracic radiculopathy. A thorough history, physical examination, and testing that includes electrodiagnostic examination and imaging studies may distinguish radiculopathy from other pain sources. Although various electrodiagnostic examinations may help evaluate radiculopathy, needle electromyography is the most important, sensitive, and specific method. Outcome studies of conservative treatments have shown varying results and have not been well controlled or systematic. When legitimate incapacitating symptoms continue despite conservative treatment attempts, more invasive spinal procedures and intradiscal treatment may be appropriate. Surgery has been shown to have excellent clinical outcomes in patients with disc extrusion and neurological deficits. However, patients with minimal disc herniation have fair or poor surgical outcomes. In addition, conventional open disc surgery entails various inadvertent surgical related risks. Although there has not yet been a non-surgical interventional procedure developed with the therapeutic efficacy of open surgery, conservative procedures can offer substantial benefits, are less invasive, and avoid surgical complications. While more invasive procedures may be appropriate when conservative treatment fails, prospective studies evaluating cervical and thoracic radiculopathies treatment options would help guide practitioners toward optimally cost-effective patient evaluation and care.