• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.219-220
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• 2006

Laser surface hardening technologies have been used to improve characteristics of wear and to enhance the fatigue resistance for mold parts. The objective of this research work is to investigate the influence of the process parameters, such as power of laser and defocused spot position, on the characteristics of laser surface hardening for the case of SKD61 steel. CW Nd:YAG laser is selected as the heat source. The optical lens with the elliptical profile is designed to obtain a wide surface hardening area with a uniform hardness. From the results of the experiments, it has been shown that the maximum hardness is approximatly 740 Hv when the power, focal position and the travel of laser are 1,095 W, +1mm and 0.3 m/min, respectively. In addition, the hardening width using the elliptical lens was three time larger than that using the defocusing of laser beam.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.18 no.3
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• pp.411-420
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• 2011

Purpose: The aim of this study was to exam differences in awareness and ethical attitudes associated with Do-Not- Resuscitate (DNR) among emergency department's team. Method: The participants in this study were 402 emergency department's team working in the 41 hospitals. The data was collected by using "awareness measuring tool" by Kang (2003) and "ethical attitudes measuring tool" by Ko (2004) from May 1 to September 15, 2009. Collected data were analyzed by descriptive statistics, t-test, Pearson correlation coefficient using SPSS WIN 14.0 program. Results: 74.4% of subjects was responded that they had never been educated about DNR, but 73.9% of subjects was responded that they had experienced DNR in the emergency room. The majority of subjects responded that the patients and their families should make a decision about the DNR. There was a difference in an appropriate time for explanation of DNR among emergency department's team. There was a difference in ethical attitudes associated with Do-Not- Resuscitate among emergency department's team. Conclusion: For a professional and systematic approach to the problem, DNR guideline sufficient to elicit a social consensus is needed.

• Journal of the Korea Society of Computer and Information
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• v.28 no.2
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• pp.1-7
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• 2023

In this paper, we propose a base address candidate selection method using the $gp register and page granularity as a way to build a static analysis environment for firmware based on MIPS architecture. As a way to shorten the base address search time, which is a disadvantage of the base address candidate selection method through inductive reasoning in existing studies, this study proposes a method to perform page-level search based on the $gp register in the existing base address candidate selection method as a reference point for search. Then, based on the proposed method, a base address search tool is implemented and a static analysis environment is constructed to prove the validity of the target tool. The results show that the proposed method is faster than the existing candidate selection method through inductive reasoning.

• Transactions of Materials Processing
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• v.24 no.5
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• pp.361-367
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• 2015

The forming limit diagram (FLD) is the most commonly used tool for evaluating of sheet metal formability in the manufacturing field as well as the finite element analysis (FEA)-based design process. Determination of the forming limits is considerably influenced by testing/measuring machines, techniques and conditions. These influences may cause a large scatter in FLD from laboratory to laboratory. Scatter is especially true when the ‘position-dependent method’, as is specified in most national and international standards, is used. In the current study a new ‘time-dependent method’ is proposed, which is to determine the forming limit strains more accurately and reasonably when producing a FLD from experimental data. This method is based on continual strain measurement during the test. The results are compared to those from the existing standardized methods.

• Cartoon and Animation Studies
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• s.13
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• pp.237-253
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• 2008

Visual Effects have been revered as 'Spectacular' film elements for a long time, and once there was a misunderstanding that they destroyed the actual 'Story'. But, now they are becoming a valuable tool for storytellers. A film pursues a perfect narrative structure and visual reality so that the audience can believe the story as a real. Giving a narrative motif to the audience, they use Visual Effects that provide the technical solutions and -at the same time- they create and preserve the diegetic world that Is either believable or not. This research suggests that we analyze precisely and make a classified table of the narrative use of Visual Effects based on the previous research of Shilo T. McClean. First, we can ask if the narrative motif would be there in front of the camera, From there, we then can get two desired answers. One is, if there is nothing to visually stand up, Visual Effects can intervene as an alternative tool for creating the diegetic world. The other is that Visual Effects can be used for preserving the diegetic world as a necessary tool. Then, in the latter, we can consider whether there is a storyteller's purpose to be added, so we can distinguish the details. This classified Visual Effects for the narrative is able to dispense proof that they can be worthy as to provide a 'Spectacuiar' aura as to create and preserve the diegetic world. I would like to argue that this research could be a foundation for the inter-progress of future studies for visual effects as well as for their amazing technological improvements.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.6
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• pp.14-22
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• 2008

This study is aimed at suggesting a linear-type diffuser which is excellent in terms of range and elegance like existing diffusers in which amount and direction of wind can be freely controled, out of linear-type diffusers with the highest possibility to be adopted for living space of apartments whose height between floors is not so high and utilizing the linear-type diffuser in design. For the purpose, I examined necessary flow and noise properties of linear-type diffusers. Besides, I evaluated its ventilation capacity for persons in there by applying this in the actual living space. I evaluated features and air blast and found that in time of horizontal and vertical effusion, its T/L ratio is 1-1.5, similar to existing cardioid-type linear diffusers, while in time of slope effusion, it is similar to horizontal effusion in terms of range and it has medium figure in terms of pressure drop and effusion speed, indicating it can provide safe and pleasant indoor environment for persons in there in terms of ventilation.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.5
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• pp.36-43
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• 2008

This research is tendencious to manufacture solid piston-rod of shock absorber as hollow piston-rod using friction welding. The SM45C has been welded to the SM45C-pipe in order to investigate the effect of upset pressure on friction weldability. The friction time and upset pressure was variable conditions under the conditions of spindle revolution of 2,000rpm, friction pressure of 55MPa, and upset time of 2.0seconds. Under these conditions, the microstructure of weld interface, tensile fracture surface and mechanical tests were studied of friction weld, and so the results were as follows. When the upset pressure is sufficient, gets the high tensile strength. The optimal welding conditions were n=2,000rpm, $P_1$=55MPa, $P_2$=95MPa, $t_1$=1.5sec, $t_2$=2.0sec when the total upset length is 4.5mm.

• Women's Health Nursing
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• v.30 no.2
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• pp.128-139
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• 2024

Purpose: This study aimed to translate the Perinatal Infant Care Social Support (PICSS) instrument into Chinese and to verify the reliability and validity of the translated version. Methods: This study used a cross-sectional design to examine the reliability and validity of the Chinese version of the PICSS (C-PICSS). A cohort of 150 first-time mothers in China participated, attending hospital follow-up care at 6 weeks postpartum. Data were collected after obtaining informed consent from the mothers. Results: The majority of mothers were aged between 20 and 29 years, with a mean age of 26.25 (±3.90) years. An item analysis of the 19 items in the C-PICSS showed that all items had an item-total score correlation above 0.2. This resulted in a Kaiser-Meyer-Olkin value of 0.92 and a significant Bartlett's test of sphericity (χ²=1,778.65, p<.001), confirming the suitability of the data for factor analysis. Correlation analyses revealed a strong positive relationship between infant care social support and general social support (r=.62, p<.001), and a negative relationship between infant care social support and postpartum depression (r=-. 38, p<.001). Higher scores for infant care social support were associated with reporting positive relationships with their husbands (t=3.72, p<.001) and high levels of spousal involvement (t=4.09, p<.001). In terms of structural support, spouses were identified as the primary source. Conclusion: The research results indicate that C-PICSS is reliable and valid as an indicator of social support for infant care among Chinese mothers.

• Investigative Magnetic Resonance Imaging
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• v.7 no.1
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• pp.39-46
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• 2003

Purpose : To develop a theoretical model for magnetic relaxation behavior of the superparamagnetic nano-particle agent, which demonstrates multi-functionality such as liver- and lymp node-specificity. Based on the developed model, the computer simulation was performed to clarify the relationship between relaxation time and the applied magnetic field strength. Materials and Methods : The ultrasmall superparamagnetic iron oxide (USPIO) was encapsulated with biocompatiable polymer, to develop a relaxation model based on outsphere mechanism, which was resulting from diffusion and/or electron spin fluctuation. In addition, Brillouin function was introduced to describe the full magnetization by considering the fact that the low-field approximation, which was adapted in paramagnetic case, is no longer valid. The developed model describes therefore the T1 and T2 relaxation behavior of superparamagnetic iron oxide both in low-field and in high-field. Based on our model, the computer simulation was performed to test the relaxation behavior of superparamagnetic contrast agent over various magnetic fields using MathCad (MathCad, U.S.A.), a symbolic computation software. Results : For T1 and T2 magnetic relaxation characteristics of ultrasmall superparamagnetic iron oxide, the theoretical model showed that at low field (<1.0 Mhz), $\tau_{S1}(\tau_{S2}$, in case of T2), which is a correlation time in spectral density function, plays a major role. This suggests that realignment of nano-magnetic particles is most important at low magnetic field. On the other hand, at high field, $\tau$, which is another correlation time in spectral density function, plays a major role. Since $\tau$ is closely related to particle size, this suggests that the difference in R1 and R2 over particle sizes, at high field, is resulting not from the realignment of particles but from the particle size itself. Within normal body temperature region, the temperature dependence of T1 and T2 relaxation time showed that there is no change in T1 and T2 relaxation times at high field. Especially, T1 showed less temperature dependence compared to T2. Conclusion : We developed a theoretical model of r magnetic relaxation behavior of ultrasmall superparamagnetic iron oxide (USPIO), which was reported to show clinical multi-functionality by utilizing physical properties of nano-magnetic particle. In addition, based on the developed model, the computer simulation was performed to investigate the relationship between relaxation time of USPIO and the applied magnetic field strength.

• Journal of Korean Neurosurgical Society
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• v.65 no.2
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• pp.276-286
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• 2022

Objective : Spinal cord stimulation (SCS) is an effective treatment for chronic neuropathic pain. However, its clinical efficacy in regard to specific types of pain has not been well studied. The primary objective of this study was to retrospectively analyze the clinical outcomes of paddle-type SCS according to the type of neuropathic pain. Methods : Seventeen patients who underwent paddle-lead SCS at our hospital were examined. Clinical outcomes were evaluated pre- and postoperatively (3 months, 1 year, and last follow-up) using the Neuropathic Pain Symptom Inventory (NPSI). The NPSI categorizes pain as superficial, deep, paroxysmal, evoked, or dysesthesia and assess the duration of the pain (pain time score). Changes in NPSI scores were compared with change in Visual analogue scale (VAS) scores. Results : After SCS, the pain time score improved by 45% (independent t-test, p=0.0002) and the deep pain score improved by 58% (independent t-test, p=0.001). Improvements in the pain time score significantly correlated with improvements in the VAS score (r=0.667, p=0.003, Spearman correlation). Additionally, the morphine milligram equivalent value was markedly lower after vs. before surgery (~49 mg, pared t-test, p=0.002). No preoperative value was associated with clinical outcome. Conclusion : The NPSI is a useful tool for evaluating the therapeutic effects of SCS. Chronic use of a paddle-type spinal cord stimulation improved the deep pain and the pain time scores.