• Food Science and Biotechnology
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• v.17 no.1
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• pp.102-105
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• 2008

The freezing patterns of commercial frozen foods were characterized by using proton nuclear magnetic resonance ($^1H$ NMR) relaxometry and differential scanning calorimetry (DSC). The liquid-like components like unfrozen water were investigated as a function of temperature (10 to $-40^{\circ}C$) and then compared with the unfrozen water content measured by DSC. The formation of ice crystals and the reduction of water in the foods during freezing were readily observed as a loss of the NMR signal intensity. The proton NMR relaxation measurement showed that the decreasing pattern of the liquid-like components varied depending on the samples even though they exhibited the same onset temperature of ice formation at around $0^{\circ}C$. When compared with the unfrozen water content obtained by the DSC, the NMR and DSC results could be closely correlated at the temperature above $-20^{\circ}C$. However, the distinct divergence in the values between 2 methods was observed with further decreasing temperatures probably due to the solid glass formation which was not detected by DSC.

• Atmosphere
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• v.33 no.4
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• pp.367-385
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• 2023

The variabilities of precipitation and particulate matters (i.e., PM₁₀ and PM_2.5) and the scavenging efficiency of PMs by precipitation were quantified using long-term measurements in Seoul, Korea. The 21 years (2001~2021) measurements of precipitation and PM₁₀ mass concentrations, and the 7 years (2015~2021) of PM_2.5 mass concentrations were used. Statistical analysis was performed for each period (i.e., year, season, and month) to identify the long-term variabilities of PMs and precipitation. PM₁₀ and PM_2.5 decreased annually and the decreasing rate of PM₁₀ was greater than PM_2.5. The precipitation intensity did not show notable variation, whereas the annual precipitation amount showed a decreasing trend. The summer precipitation amount contributed 61.10% to the annual precipitation amount. The scavenging efficiency by precipitation was analyzed based on precipitation events separated by 2-hour time intervals between hourly precipitation data for 7 years. The scavenging efficiencies of PM₁₀ and PM_2.5 were quantified as a function of precipitation characteristics (i.e., precipitation intensity, amount, and duration). The calculated average scavenging efficiency of PM₁₀ (PM_2.5) was 39.59% (35.51%). PM₁₀ and PM_2.5 were not always simultaneously scavenged due to precipitation events. Precipitation events that simultaneously scavenged PM₁₀ and PM_2.5 contributed 42.24% of all events, with average scavenging efficiency of 42.93% and 43.39%. The precipitation characteristics (i.e., precipitation intensity, precipitation amount, and precipitation duration) quantified in these events were 2.42 mm hr^-1, 15.44 mm, and 5.51 hours. This result corresponds to 145% (349%; 224%) of precipitation intensity (amount; duration) for the precipitation events that do not simultaneously scavenge PM₁₀ and PM_2.5.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.47-47
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• 2009

The photoconductive $CdGa_2Se4$ layer has been investigated using photocurrent (PC) spectroscopy as a function of temperature. Three peaks corresponding to the band-to-band transitions were observed in the PC spectra for all temperature ranges. Also, contrary to our expectation, the PC intensities decreased with decreasing temperatures. From the relation of log $J_{ph}$ vs 1/T, where $J_{ph}$ is the PC density, two dominant levels by the exponential variation of the PC with varying temperature were observed, one at high temperatures and the other at low temperatures.

• Bulletin of the Korean Chemical Society
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• v.30 no.6
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• pp.1337-1340
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• 2009

Electrical properties of a fluorinated carbon black (CB)-filled high-density polyethylene (HDPE) polymeric switch were investigated as a function of fluorination pressure at 0.1 ~ 0.4 MPa. From the FT-IR results, the absorption spectra of the fluorinated CB show an absorption band at 1400 ~ 1000 $cm^{-1}\;for\;{\nu}_{C-F}$ and the peak intensity increased with increasing fluorination pressure. Also, the analysis of XPS spectra of the fluorinated CB indicated that fluorine content increased with increasing fluorination pressure. Meanwhile, the surface free energy of the fluorinated CB decreased with increasing fluorination pressure. Consequently, the increase of fluorine contents of CB made a disappearance of negative temperature coefficient (NTC) behavior of the polymeric switch, which was probably due to the reduction of CB reaggregation after melting point of the HDPE, resulted from the decreasing of London dispersive component of the surface free energy for CB particles.

• Journal of Korean Academy of Nursing
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• v.36 no.1
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• pp.94-102
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• 2006

Purpose: The purpose of this study was to confirm the effects of a moderate and fast walking exercise program on middle-aged women's fatigue, serum lipids and immunoglobulins. Method: A non-equivalent control group pretest-posttest design was used for this study. The experiment was conducted for 10 weeks from May 17th to July 25th, 2004 with 44 middle-aged women, consisting of 16 for the moderate walking group, 15 for the fast walking group and 13 for the control group. Result: Walking exercise at both a moderate and fast speed was effective in middle-aged women in reducing fatigue and serum lipids. It was also revealed that extended periods of exercise was more effective in decreasing fatigue while for reducing serum lipid, high intensity exercise was more effective. In this study, serum immunoglobulins were reduced after moderate and fast walking exercise but its cause was not fully understood so further research is needed. Conclusion: This study helps us recognize the importance of regular exercise and promotes motivation to exercise for a healthy life among middle-aged women.

• Convergence Security Journal
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• v.10 no.1
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• pp.55-61
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• 2010

It is of great practical interest to deciding when to stop testing a software system in development phase and transfer it to the user. This decision problem called an optimal release policies. In this paper, because of the possibility of introducing new faults when correcting or modifying the software, we were researched release comparative policies which based on infinite failure NHPP model and types of interval failure times. The policies which minimize a total average software cost of development and maintenance under the constraint of satisfying a software reliability requirement can optimal software release times. In a numerical example, applied data which were patterns, if intensity function constant or increasing, decreasing, estimated software optimal release time.

• Atmosphere
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• v.22 no.1
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• pp.13-28
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• 2012

The $PM_{10}$ concentration data is useful for indentifying intensity and a transport way of Asian dust. However, it is difficult to identify them properly due to the limited spatial resolution and coverage. Therefore, a methodology to estimate $PM_{10}$ concentration using visibility data obtained from synoptic observation was developed. To derive the converting function, correlation between visibility and $PM_{10}$ concentration is investigated using visibility and $PM_{10}$ concentration data observed at 20 stations in Korea from 2005 to 2009. To minimize bias due to atmospheric moisture, data with higher relative humidity over a critical value were eliminated while deriving $PM_{10}$-visibility relationship. As a result, an exponentially decreasing function of visibility is obtained under the condition that relative humidity is less than 82%. Verification of the visibility converting function to $PM_{10}$ concentration was carried out for the dust cases in 2010. It was found that spatial distributions of $PM_{10}$ calculated by visibility are in good agreement with the observed $PM_{10}$ distribution, especially for the strong dust cases in 2010. And correlation between the derived and observed $PM_{10}$ concentration was 0.63. We applied the function to obtain distributions of $PM_{10}$ concentration over North Korea, in which concentration data are not available, and compared them with satellite derived dust index, IODI distributions for dust cases in 2010. It is shown that the visibility function estimates quite similar patterns of dust concentration with IODI image, which suggests that it can contribute for prediction by indentifying transport route of Asian dust.

• Journal of International Academy of Physical Therapy Research
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• v.10 no.2
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• pp.1803-1809
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• 2019

Background: Cervical mobilization has been applied mainly for the improvement of arm and neck movements and pain reduction, and little research has been done to improve the executive function. Since this kind of so-called mechanical neck pain is one of most common symptoms, there are controversial issues about this with spine alignment. Posteroanterior (PA) mobilization from the Maitland concept is a process of examination, assessment, and treatment of neuromusculoskeletal disorder by manipulative physical therapy. Objective: To examine the short-term benefits of mobilization for patients with non-specific neck pain. Design: Dual-group Pretest-Posttest Design from the Quasi-Experimental research Methods: Fourteen participants (male 8, female 6; 20's of their age) with non-specific neck pains which are distributed all the unilateral or bilateral body side were recruited. Participants were categorized to Neck Pain with Movement Coordination Impairments (NPMCI) and Neck Pain with Mobility Deficits (NPMD) groups according to the results of physical examination. Professional physical therapist who has over 15-years-of clinical experience applicated manipulative therapy for the neck pain, an occupational therapist only conducted evaluations; K-NDI (Korean version of the Neck Disability Index), VAS (Visual Analog Scale), BDS-K (Korean version of Behavioral Dyscontrol Scale) for decreasing possible adverse effects; there were no person who reported other symptoms followed 4 weeks from the trial. Results: In the NPMCI group, data analysis indicated statistical differences between the PA mobilization interventions in NDI and BDS-K; even though, pain was reduced in VAS, this is not a significantly differ. In the NPMD group, data analysis represented statistical differences between the PA mobilization interventions in NDI, VAS and BDS-K; the scores were represented to be increased or the pain got relief. Conclusions: PA mobilization techniques according to Maitland concept have beneficial effects in patients with neck pain and other clinical positive effects which included neck disability, pain itself and motor function of upper extremity.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.4
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• pp.351-358
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• 2016

Science and technology is developing rapidly as more powerful software with the rapid development of software testing and reliability assessment by the difficulty increases with the complexity of the software features of the larger increases NHPP software reliability models for failure analysis can have, in the literature, exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, finite failure NHPP models that assuming the expected value of the defect and infinite failures NHPP models that repairing software failure point in time reflects the situation, were presented for comparing property. Commonly used in the field of software reliability based on Erlang distribution software reliability model finite failures and infinite failures were presented for performance comparative evaluation problem. As a result, finite failure model is better than infinite failure model effectively. The parameters estimation using maximum likelihood estimation in the course of this study was conducted. As the results of this research, software developers to identify software failure property be able to help is concluded.

• Journal of Energy Engineering
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• v.20 no.4
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• pp.338-345
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• 2011

The swirl flow applied for high efficiency and reduction of emission such as NOx, CO in a gas turbine engine makes recirculation zone by shear layer in the combustion chamber. This recirculation zone influences a decreasing flame temperature and flame length by burned gas recirculation. Also it is able to suppress from instability in lean-premixed flame. In this study, it was found that the swirl flow field was characterized as function of swirl number using PIV measurement in dump combustor. As increasing swirl number, a change of flow field was presented and recirculation zone was shifted in the nozzle exit direction. Also turbulent intensity and turbulent length scale in combustor were decreased in combustion. It has shown reduction of eddies scale with swirl number increasing.