• Survey Research
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• v.10 no.1
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• pp.113-139
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• 2009

It is desirable to use a monthly benchmarked construction indicator which contains the characteristics of statistical data in an annual survey in order to analyze the cyclical phenomenon of the construction activity. The benchmarked indicator is expected to improve the data quality in terms of accuracy, consistency, comparability, and completeness. In this paper, benchmarking methodologies of compiling monthly construction indicators arc researched by using a monthly prompt data holding short - term fluctuations and an annual survey data regarded as more accurate statistics than monthly data. The benchmarking is the methodology by which a high frequency data should he adjusted in order to hold the short-term and cyclical phenomena, and the long - term trend of two data groups with ensuring the consistency of an annual summation between a high frequency data and a low frequency data. This paper considered the numerical approach like pro rata distribution method, proportional Denton method, EFL or HP filter Benchmark - to - Indicator ratio method, and the model - based approach such as Chow and Lin method, $Fem{\acute{a}}ndez$ method. Also, the benchmarked construction indicators were estimated by early mentioned benchmarking methods with practical data, and these methods were empirically reviewed and compared. In case of construction indicators with severe seasonal fluctuations and irregulars, the numerical approach seemed to be performed more correctly than the model- based approach. Among numerical methods, the proportional Denton method used in general was a little nice. The HP filter Benchmark - to - Indicator ratio method may be considered with survey errors or measurement errors in an annual survey data.

• Korean Journal of Environment and Ecology
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• v.32 no.3
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• pp.313-322
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• 2018

To investigate the changing patterns of sub-alpine forest vegetation due to climate change requires accumulation of contiguous reference data and continuous monitoring. Furthermore, it is crucial to monitor short-term ecological change of lower level vegetation to understand the trend of long-term vegetation change. Therefore, this study carried out a vegetation survey and tree diameter measurement in 36 plots of Mt. Jiri inhabited by Abies koreana species from 2015 to 2017 to examine the short-term dynamics of Abies koreana seedling and the change of vegetation distribution according to altitude. We analyzed the importance value and MIV (mean importance value) of major species by each stratum as well as the importance value and species diversity index of major species and the change of seedling population by altitude. The results showed that Abies koreana had the highest importance value on tree layer, Rhododendron schlippenbachii on shrub layer and Tripterygium regelii on herb layer. MIV was high in the order of Abies koreana, Rhododendron schlippenbachii and Acer pseudosieboldianum. Regarding the species composition and species diversity index (H') along the altitudinal gradient, Sasa borealis showed high MI and low H' in the elevation less than 1,500 m, and IV of Tripterygium regelii and H' of herb layer were high in the elevation of 1,700 - 1,800 m. Abies koreana seedling decreased by 22.4% from 1,250 n/ha in 2015 to 970 n/ha in 2017 (p <0.05) throughout the investigated area. The decline rate along seedling and sapling height were 22.9% in less than 10 cm, 3.4% in 10-30 cm, 8.9% in 30-50 cm, 39.3% in 50-100 cm, and 55.1% more than 100 cm. Few of A. koreana seedlings appeared due to the dominance of Sasa borealis in the elevation of 1,500 m or less and due to the dominance and high species diversity of Tripterygium regelii in the elevation of 1,700-1,800 m. On the other hand, many of A. koreana seedlings appeared in the elevation of 1,600-1,700 m due to no distribution of S. borealis and T. regelii species in that altitude range. Therefore, we concluded that those seedlings and saplings of A. koreana could be more stable in the altitude of 1,600-1,700 m.

• The Korean Journal of Pain
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• v.35 no.1
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• pp.106-113
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• 2022

Background: Coccygodynia is one of the chronic, refractory painful musculoskeletal disorders. Interventional procedures are applied to patients unresponsive to initial treatment in coccygodynia. This study aims to compare the treatment outcomes of ganglion impar block (GIB) and caudal epidural steroid injection (CESI) in patients with chronic coccygodynia. Methods: This study was a prospective randomized comparison study conducted between June 2019 and January 2021. Patients diagnosed with chronic coccygodynia were randomly divided into two groups: the GIB group and the CESI group. The severity of pain, presence of neuropathic pain, and quality of life were evaluated using the Numeric Rating Scale, Leeds Assessment of the Neuropathic Symptoms and Signs Scale, and Short Form-12 Health Survey (SF-12), respectively. Results: A total of 34 patients in each group were included in the final analyses. While there was a significant decrease in pain intensity in both groups in the 3-month follow-up, this decrease was more significant in the GIB group at the 3rd week. There was a significant improvement in the SF-12 physical score and the number of patients with neuropathic pain in both groups in the 3rd week, but this improvement was not observed in the 3rd month. Conclusions: Although GIB may provide more pain relief in short term, both GIB and CESI are useful treatment methods in coccygodynia unresponsive to more conservative treatments.

• Transactions on Electrical and Electronic Materials
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• v.7 no.1
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• pp.16-20
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• 2006

In this paper, we investigated the effects of short-term oxygen plasma treatment of semiconducting silicone layer to improve interfacial performances in joints prepared with a insulating silicone materials. Surface characterizations were assessed using contact angle measurement and x-ray photoelectron spectroscopy (XPS), and then adhesion level and electrical performance were evaluated through T-peel tests and electrical breakdown voltage tests of treated semi-conductive and insulating joints. Plasma exposure mainly increased the polar component of surface energy from $0.21\;dyne/cm^2$ to $47\;dyne/cm^2$ with increasing plasma treatment time and then leveled off. Based on XPS analysis, the surface modification can be mainly ascribed to the creation of chemically active functional groups such as C-O, C=O and COH on semi-conductive silicone surface. This oxidized rubber layer is inorganic silica-like structure of Si bound with three to four oxygen atoms ($SiO_x,\;x=3{\sim}4$). The oxygen plasma treatment produces an increase in joint strength that is maximum for 10 min treatment. However, due to brittle property of this oxidized layer, the highly oxidized layer from too much extended treatment could be act as a weak point, decreasing the adhesion strength. In addition, electrical breakdown level of joints with adequate plasma treatment was increased by about $10\;\%$ with model samples of joints prepared with a semi-conducting/ insulating silicone polymer after applied to interface.

• KIEAE Journal
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• v.1 no.2
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• pp.21-28
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• 2001

Naturally-ocurring short-lived decay products of radon gas in indoor air are the dominant source of ionizing radiation exposure to the general public. It is written in BEIR VI Report(l999l the radon progeny were identified as the second cause of lung cancer next to cigarette or 10 % to 14 %(15,400 to 21,800 persons p.a.) of all lung cancer deaths in USA. Indoor radon concentrations in houses typically result from radon gaining access to houses mainly from the underlying soil. In the States, they have "Indoor Radon Abatement Act" which was converted from "Toxic Substance Control Act" in 1988 to establish the national long-term goal that indoor air should be as free of radon as the ambient air outside of buildings. To review and study techniques for controlling radon, two test cells were constructed for a series of tests and are under measuring indoor and soil gas (underneath of floor slab)radon concentrations according to EPA's measurement protocol. In this paper, important theoretical studies are previewed and the following paper will explain the test results and confirm the theories reviewed to find out suitable coefficients. On the basis of test analysis, it will be described and evaluated various techniques that can be used to mitigate elevated indoor concentration of radon including the control of radon and its decay products.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.18 no.4
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• pp.480-487
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• 2011

Purpose: This study was done to examine the effects of aroma hand massage on stress response and sleep in hospitalized elderly patients. Methods: A non-equivalent pre-and post-test design was used. Sixty-six hospitalized patients were recruited using a convenience sampling method and assigned to the experimental (n=34) or the control group (n=32). For the experiment, bergamot, lavender, and roman camomile oil were mixed in 2:1:1 ratio to provide aroma hand massage to both hands of each patient in the experimental group for 5 minutes per hand, for 3 days. Post-test data collection was conducted three days after completion of the hand massage. Results: The experimental group had significantly lower stress score (t=-2.648, p=.010, and anxiety scores (t=-4.166, p=.000), and higher sleep measurement scores (t=2.328, p=.023) than those in the control group. Conclusion: These results indicate that short-term application of aroma hand massage for hospitalized elderly patients has a positive effect on hospitalization stress, anxiety, and sleep. Therefore, aroma hand massage should be applied as a nursing intervention to reduce stress response and enhance sleep in elderly hospitalized patients.

• Journal of electromagnetic engineering and science
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• v.9 no.3
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• pp.118-123
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• 2009

This paper discusses the design and fabrication of a reference signal generator for a naval radar system, including the vibration environment test. The transmit signals of the S-band radar system are synthesized by the reference signal and the phase noise must lower than - 130 dBc/Hz at a 10 kHz offset frequency. To achieve this specification, the phase noise of the reference signal needs to be less than -165 dBc/Hz at a 10 kHz offset. For achieving very low phase noise performance by the reference signal generator, the phase locked loop technique is applied with a 10 Hz loop bandwidth. Also, this reference signal generator has ${\pm}0.35\;ppb$ short-term stability to minimize instant phase errors and high vibration sensitivity against a ship's shaking, unbalanced rotating of antennas and so on.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.12
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• pp.1279-1286
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• 2004

This paper continues companion paper, part I : measurement and analysis. As shown in companion Paper, information and energy in monaural signal is quite different from that of binaural signal. In this paper, difference between monaural and binaural signal of transportation noise are investigated in subjective response test. We executed hearing screening test before giving a subject response test and excluded subjects who had physical hearing loss. An annoyance response test was conducted using headphone to avoid cross-talk effect in binaural testing. Percentage of highly annoyed under binaural signal reproduction is higher than percentage of highly annoyed under monaural signal reproduction. Result implies binaural reproduction technique is proper for a study of human response to short-term noise exposure in a headphone simulated-environment.

• Journal of the Korean Society for Railway
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• v.9 no.2 s.33
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• pp.230-236
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• 2006

For a short-term measurement to reduce an accident on a railroad crossing, it is necessary to find out the weakness and problems of existing equipment in the railroad transportation system. The analysis of railroad crossing accidents shows that main causes of accidents (24.9%) are the careless driving including an engine problem, damage on the safety equipment, slide on the snow, and an engine stop on the railroad crossing. Therefore, it is required to install a sensor, or to make a crossing gate at the exist for detecting obstacles on a railroad to prevent collisions among trains. This paper suggests 'a panel sensor using the strain gauge' to make up the weaknesses of the sensing Dead Zone, which are caused by using a laser method, and to detect any small objects passing railroads in order to reduce the errors, which are occurred in the earth magnetic field for controlling Exit Slide Crossing Arm Detector. The device, suggested in this paper, is verified with detecting any small objects passing the railroad, with judging entry decision clearly, and with controlling passing gate and obstruction warnings/cautions obstacles at the same time, through an experimental test.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.4
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• pp.271-277
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• 1993

Indoor radon has been known as one of the notorious carcinogens. However, a safe environmental criterion of radon has not yet been established in Korea, The main objectives of this study were to study concentration distributions of radon, to trace radon sources in subways, and to obtain a strategy for radon reduction in Seoul metropolitan area. Radon concentrations had been extensively determined by several steps. The first step was to survey radon levels in all of 83 subway stations from October to November in 1991. The second step was to select 40 out of 83 stations and then to study seasonal variations in 1991 and 1992. The third step was to monitor radon levels by hourly-basis plans. The fourth step was to seek a radon reduction strategy by altering ventilation at Ankuk station where had the highest radon concentration during the first measurement step. Each underground floor in the station was divided into 10 sites to measure hourly radon variations. The final step of the study was to measure radon concentrations in groundwater that is one of the possible main sources radon place. The result of the various measuring approaches showed short-and long-term radon variation and indicated radon reduction schemes.