• Title/Summary/Keyword: phase difference

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The Comparison of the Perceived Needs between Patients with Cancer, their Caregivers, and Nurses According to the Cancer Patient,s Phases of Illness (질병단계에 따라 암환자, 돌보는 가족원, 간호사의 간호요구 지각 비교)

  • 양영희
    • Journal of Korean Academy of Nursing
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    • v.27 no.4
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    • pp.787-795
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    • 1997
  • This descriptive study was conducted to ascertain whether the needs of patients with cancer, their caregivers and their nurses changed according to the illness phases and if the perceived needs of the three groups were different for three categories of nursing needs. At two hospitals in Seoul and Choongnam, three groups of subjects, -patients with cancer(79), caregivers(92), and nurses(72) - responded to a questionnaire consisting of items on educational need(11 items), physical need(8 items), emotional need(9 items) using a 4-point Likert scale. The patients and caregivers were selected according to the phase of the cancer (initial, intermediate or recurred, terminal phases). Finding revealed that the level of perception and degree of satisfaction of the needs were low, just around two points in patients and caregivers. Of the three categories of needs, physical needs were received the highest score and the degree of satisfaction of physical needs was also the highest. There was no significant difference between the level of perception and satisfaction of needs in patients and caregivers according to the phases of the illness and the degree of per reception and the satisfaction of the patients were not significantly different and caregivers showed the same result. There was a significant difference in the level of importance of the needs of nurses according to the phases of the cancer. They perceived emotional needs were the most important in first phase and second phase, physical needs in third phase and the educational needs were more important in the first phase than in any other phase. The degree of importance of needs was significantly lower than the degree to which needs were addressed, according to the nurses response. In a comparison of patient and caregiver's perceived degrees of need, and need satisfaction, and nurse's perceived degree of need provision, patient and caregiver scores were lower than the nurses.

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Inhibitory Effect of adding Phase Change Material (PCM) to Fire Fighter Protective Clothing on Burn Injuries (Phase Change Material (PCM) 소재 적용 소방보호복의 화상발생 억제효과에 관한 연구)

  • Lee, Jun Kyoung
    • Fire Science and Engineering
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    • v.30 no.3
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    • pp.16-22
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    • 2016
  • Fire fighters rely on fire fighter protective clothing (FFPC) to provide adequate protection in the various hazardous environments. To enhance its protection performance, the FFPC material must be thick and thus it is difficult to achieve weight reduction. One of the methods of overcoming this problem, the addition of phase change material (PCM) to FFPC, is a new technology. In previous studies, the researches was mostly related to the temperature characteristics of the fibers incorporating PCM, but little information is available about its effect on burn injuries. Thus, in this study, the inhibitory effects of adding PCM to FFPC on second degree burns were investigated through numerical calculations. Thermal analyses of biological tissues and FFPC with embedded PCM exposed to several fire conditions causing severe tissue damage were studied by using a finite difference method based on the Pennes bio-heat equation. FFPC with embedded PCM was found to provide significantly greater protection than conventional fire fighting clothing, because the heat of absorption due to the phase change within the material is used to limit the heat conduction of the material.

Reflection-Type 5-bit Digital Phase Shifter with Constant Insertion Loss (균일 삽입 손실 특성을 갖는 반사형의 5-비트 디지털 위상 변위기)

  • 고경석;최익권
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.6
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    • pp.582-589
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    • 2002
  • This paper presents 12.2 GHz ~ 12.7 GHz frequency band reflection type 5-bit digital phase shifter with constant insertion loss property that was fabricated with relatively low cost's InGaAs HEMT for amplifier. The unavoidable large insertion loss difference between on and off states of HEMT, when it is designed by conventional design theory based on ideal switching device, is removed by transforming the HEMT impedances at on and off states to other proper values connecting a certain length transmission line to HEMT and then applying the conventional design theory. The fabricated 5-bit digital phase shifter shows very good insertion loss properties of less than 1.5 dB insertion loss difference and -4.5 dB ~ -6 dB insertion loss in 35 phase steps at 12.2 GHz ~ 12.7 GHz. These results verify the design method presented in this paper, which is useful to design phase shifter of constant insertion loss with non-ideal switching device.

Crystallization Properites of $Te_x(Sb_{85}Ge_{15})_{100-x}$ Thin Film as Phase Change Optical Recording Media ($Te_x(Sb_{85}Ge_{15})_{100-x}$ 상변화 광기록 박막의 결정화 특성)

  • 김홍석;이현용;정홍배
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.4
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    • pp.314-320
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    • 1998
  • In this study, we have investigated crystallization properties of $Te_x(Sb_{85}Ge_{15})_{100-x}$ (x=0.3, 0.5, 1.0) thin films prepared by thermal evaporation. The change of reflectance according to phase change from amorphous to crystalline phases with annealing and exposure of diode laser is measured b the n&k analyzer and the surface morphology between amorphous and crystalline phase is analyzed by SEM and AFM. The difference in reflectance($\DeltaR$) between amorphous and crystalline phase appears approximately 20% at the diode laser wavelength, 780nm in all prepared films. Especially, the reflectance difference,$\DeltaR$ comes up to about 30% in $Te_{0.5}(Sb_{85}Ge_{15})_{99.5}$ thin film. Also, amorphous-to-crystalline phase change is observed in all prepared films. As a result of the measurement of the reflectance using diode laser, the reflectance is increased in proportion to the laser power and exposure time in all films. As a result of observing each film with the SEM and AFM, the surface morphology of the annealed and the exposed films are evidently increased than those of as-deposited films. The fast crystallization is occurred by increasing in Te content. Therefore, we conclude that the $Te_{0.5}(Sb_{85}Ge_{15})_{99.5}$ and $Te_1(Sb_{85}Ge_{15})_{99}$ thin films can be evaluated as an attractive optical recording medium with high contast ratio and fast erasing time due to crystallization.

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The Selection of Optimum Measurement Method of Antimicrobial Activity and Constituent Phase of Yuggi Alloy according to Heat Treatment Condition (유기합금의 열처리조건에 따른 구성상의 제어와 최적 항균특성 측정방법의 선정)

  • Park, Kyu-Ha;Hwang, Dae Youn;Son, Hong-Joo;Choi, Ji Woong;Kim, Hye Sung
    • Journal of the Korean Society for Heat Treatment
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    • v.34 no.5
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    • pp.233-238
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    • 2021
  • The mechanical, anti-tarnishing, and corrosion characteristics of Yuggi (Cu-22wt%Sn) alloy are greatly affected by fraction of constituent phases according to heat treatment method. The Yuggi heat-treated at 750℃ has a β1' phase of 98% or more, which is a high-temperature disordered beta phase, on the other hand, cast Yuggi that Sn is solid-solutioned into Cu consists with α-phase over 60v/o. This difference of constituent phases of Yuggi may cause a difference in dissolution of Cu under antimicrobial test condition. Nonetheless, few studies have been conducted on the effect of fraction of constituent phases and constituent phases in antimicrobial activity. In addition, few studies have also been conducted on the suitable method measuring the antimicrobial activity of Yuggi. Hence, the purpose of this study is to provide an optimum measurement method of antimicrobial activity, and to evaluate quantitatively the effect of constituent phases on antimicrobial activity.

Comparison of Lower Extremity Electromyography and Ground Reaction Force during Gait Termination according to the Performance of the Stop Signal Task (정지신호과제의 수행에 따른 보행정지 시 다리 근전도 및 지면반발력 비교)

  • Koo, Dong-Kyun;Kwon, Jung-Won
    • PNF and Movement
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    • v.20 no.1
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    • pp.135-145
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    • 2022
  • Purpose: The purpose of this study was to investigate the association between cognitive and motor inhibition by comparing muscle activity and ground reaction force during unplanned gait termination according to reaction time measured through the stop-signal task. Methods: Sixteen young adults performed a stop-signal task and an unplanned gait termination separately. The subjects were divided into fast and slow groups based on their stop-signal reaction time (SSRT), as measured by the stop-signal task. Electromyography (EMG) and ground reaction force (GRF) were compared between the groups during unplanned gait termination. The data for gait termination were divided into three phases (Phase 1 to 3). The Mann-Whitney U test was used to compare spatiotemporal gait parameters and EMG and GRF data between groups. Results: The slow group had significantly higher activity of the tibialis anterior in Phase 2 and Phase 3 than the fast group (p <0.05). In Phase 1, the fast group had significantly shorter time to peak amplitude (TPA) of the soleus than the slow group (p <0.05). In Phase 2, the TPA of the tibialis anterior was significantly lower in the fast group than the slow group (p <0.05). In Phase 3, there was no significant difference in the GRF between the two groups (p >0.05). There were no significant difference between the two groups in the spatiotemporal gait parameters (p >0.05). Conclusion: Compared to the slow group, the fast group with cognitive inhibition suppressed muscle activity for unplanned gait termination. The association between SSRT and unplanned gait termination shows that a participant's ability to suppress an incipient finger response is relevant to their ability to construct a corrective gait pattern in a choice-demanding environment.

Simplified Noise Modeling of GPS Measurements for a Fast and Reliable Cycle Ambiguity Resolution

  • Park, Byung-Woon;Kee, Chang-Don
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.535-540
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    • 2006
  • The relationship between the observable noise model and the satellite elevation angle can be modeled quite well by an exponential function.[Jin, 1996] Noise size and dependence on the elevation angle are, however, different for each observation and receiver type. Therefore, the coefficient determination of this model is an issue, and various methods including PR-CP, single difference, and time difference have been suggested. The limitations of them are difficulty to model the carrier phase noise and to eliminate bias. To overcome these disadvantages for using Jin's model, we suggest zero baseline double difference (DD) and noise sorting algorithm. Data DD technique in zero baseline is useful to eliminate all the troublesome GPS biases, and the remaining error is the sum of GPS measurement noises from two satellites. These DD residuals for hours should be sorted by the combination of satellite elevation angles, and then variance value of the residual for each combination can be estimated. Using these values, we construct an over-determined linear equation whose solution is a set of noise variance for each satellite elevation angle. With 24hr Trimble 4000ssi data, we easily worked out the coefficients of the noise model not only for pseudorange but also for carrier phase. We estimated the standard deviation of the measurement DD using our model, and plotted 1 and 3 sigma lines for every epoch to verify the representation of the residual error. 63.3% of pseudorange residual and 65.9% of phase error did not exceed the 1 sigma lines. Additionally, 99.2% and 99.5% of them lied within 3sigma line. These figures prove that the Gaussian property of measurement noise, and that the suggested model by our algorithm corresponds to the observable noise information.

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A NEW PRESSURE GRADIENT RECONSTRUCTION METHOD FOR A SEMI-IMPLICIT TWO-PHASE FLOW SCHEME ON UNSTRUCTURED MESHES (비정렬 격자 기반의 물-기체 2상 유동해석기법에서의 압력기울기 재구성 방법)

  • Lee, H.D.;Jeong, J.J.;Cho, H.K.;Kwon, O.J.
    • Journal of computational fluids engineering
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    • v.15 no.2
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    • pp.86-94
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    • 2010
  • A thermal-hydraulic code, named CUPID, has been developed for the analysis of transient two-phase flows in nuclear reactor components. A two-fluid three-field model was used for steam-water two-phase flows. To obtain numerical solutions, the finite volume method was applied over unstructured cell-centered meshes. In steam-water two-phase flows, a phase change, i.e., evaporation or condensation, results in a great change in the flow field because of substantial density difference between liquid and vapor phases. Thus, two-phase flows are very sensitive to the local pressure distribution that determines the phase change. This in turn puts emphasis on the accurate evaluation of local pressure gradient. This paper presents a new reconstruction method to evaluate the pressure gradient at cell centers on unstructured meshes. The results of the new scheme for a simple test function, a gravity-driven cavity, and a wall boiling two-phase flow are compared with those of the previous schemes in the CUPID code.

Effect of $P_2O_5$ on the Phase Separation of $PbO-B_2O_3$ Glasses ($PbO-B_2O_3$ 계 유리의 상분리에 미치는 $P_2O_5$의 영향)

  • 최춘식;김철영
    • Journal of the Korean Ceramic Society
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    • v.22 no.4
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    • pp.47-53
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    • 1985
  • Various amount of $P_2O_5$ were added to $PbO-B_2O_3$ binary glass system to investigate its effect on the phase separation and physical properties of the glass. Experiments such as infrared spectroscopy scanning electron microscopy thermal expansion softening point and microhardnesses were done. Phase separation with $B_2O_3$ rich phase matrix and PbO rich phase droplet was observed for the glasses con-taining less than 10m/o of PbO while the opposite morphology of phase separation for the glasses containing more than 11m/o of PbO. By adding increasing amount of $P_2O_5$ their phase separation region was extended to the glass containing more than 20m/o of PbO. These effects can be interpreted in terms of the inoic field strength difference of each ions in the glasses. The abrupt changes of physical properties such as softening point thermal expansion and microhardness were observed for the glass with around 10m/o of PbO in this system. These changes are by the matrix composition change from TEX>$B_2O_3$ rich phase to PbO rich phase depending on PbO concentration.

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IMPROVEMENT OF A SEMI-IMPLICIT TWO-PHASE FLOW SOLVER ON UNSTRUCTURED MESHES (비정렬 격자계에서의 물-기체 2상 유동해석코드 수치 기법 개선)

  • Lee, H.D.;Jeong, J.J.;Cho, H.K.;Kwon, O.J.
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.380-388
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    • 2010
  • A thermal-hydraulic code, named CUPID, has been developed for the analysis of transient two-phase flows in nuclear reactor components. A two-fluid three-field model was used for steam-water two-phase flows. To obtain numerical solutions, the finite volume method was applied over unstructured cell-centered meshes. In steam-water two-phase flows, a phase change, i.e., evaporation of condensation, results in a great change in the flow field because of substantial density difference between liquid and vapor phases. Thus, two-phase flows are very sensitive to the local pressure that determines the phase change. This in turn puts emphasis on the accurate evaluation of local pressure gradient. This paper presents a new numerical scheme to evaluate the pressure gradient at cell centers on unstructured meshes. The results of the new scheme for a simple test function a gravity-driven cavity, and a wall boiling two-phase flow are compared with those of the previous schemes in the cupid code.

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