• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.5
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• pp.57-65
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• 2004

This study was carried out to measure the growth and photosynthesis of Iris pseudoacorus, the reduction rate of nitrogen(T-N) and phosphoric acid($P_2O_5$) from soils, and the increase rate of two substance into plants which cultivated at waterway soils of different concentration of two substance. The results are summarized as follows; 1. The contents of nitrogen and phosphoric acid at waterway soils of Mangyeong river showed the highest level in the around Samrye railway bridge where was located in the downstream and sewage of stock raising flowed in 2. The Iris pseudoacorus which cultivated at waterway soils showed the leaf and root growth of 43~50 and 9~13cm, respectively. And the growth was higher in the waterway soils contained high level of nitrogen The rate of photosynthesis was $3.5-5.9{\mu}mol\;m^{-2}s^{-1}$ ranges and this rate increased from the end of June to August and then decreased. The rate of photosynthesis was higher in waterway soils contained high nitrogen regardless of seasons. 4. The Iris pseudoacorus removed nitrogen and phosphoric acid from waterway soils about 19~21% and 13~15%, respectively. The Iris pseudoacorus was effective to remove nitrogen more than phosphoric acid. And the waterway soil which included high concentration of two substance showed highly removal 5. The results of Iris pseudoacorus vegetation in the waterway soils showed that nitrogen and phosphoric acid of inside plant increased with 0.2-1.0% and 0.01-0.10% ranges, respectively. The contents of nitrogen and phosphoric acid in plants were increase in the soils of higher contents of nitrogen and phosphoric acid, and the rate of increase of nitrogen and phosphoric acid was higher at roots than leaves.

• Journal of Ocean Engineering and Technology
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• v.25 no.3
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• pp.73-84
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• 2011

This is the fifth in a series of companion papers dealing with the dynamic hardening properties of various marine structural steels at intermediate strain rates. Five steps of strain rate levels (0.001, 1, 10, 100, 200/s) and three steps of temperature levels (LT ($-40^{\circ}C$), RT, and HT ($200^{\circ}C$)) were taken into account for the dynamic tensile tests of three types of marine structural steels: API 2W50 and Classifications EH36 and DH36. The total number of specimens was 180 pieces. It was seen that the effects of dynamic hardening became clearer at LT than at RT. Dynamic strain aging accompanying serrated flow stress curves was also observed from high temperature tests for all kinds of steels. The dynamic hardening factors (DHFs) at the two temperature levels of LT and RT were derived at the three plastic strain levels of 0.05, 0.10, 0.15 from dynamic tensile tests. Meanwhile, no DHFs were found for the high temperature tests because a slight negative strain rate dependency due to dynamic strain aging had occurred. A new formulation to determine material constant D in a Cowper-Symonds constitutive equation is provided as a function of the plastic strain rate, as well as the plastic strain level. The proposed formula is verified by comparing with test flow stress curves, not only at intermediate strain rate ranges but also at high strain rate ranges.

• Journal of Broadcast Engineering
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• v.17 no.3
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• pp.480-490
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• 2012

When interpolating chrominance signal, the H.264/AVC standard uses linear interpolation. In this paper, we suggest more effective method that uses a high precision filter, 6-tap FIR filter, 2-tap linear filter for chroma interpolation. The experimental result shows that the proposed method achieves the BD-Rate decrease without the PSNR decrease compared with Jm11.0kta2.7. The maximum BD-rate improvements on Y component are 1.3%, those of Cb and Cr components are 19.8%, 25.0%, respectively. The average BD-rate improvements on Y component are 0.5%, those of Cb and Cr components are 6.1%, 6.9%, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.12B
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• pp.2109-2119
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• 2000

In this paper, the Packet CDMA Reservation ALOHA protocol is proposed to support the multi-traffic services such as voice and videophone services with handoff calls, high-rate data and low-rate data services efficiently on the multi-rate transmission in uplink cellular systems. The frame structure, composed of the access slot and the transmission slot, and the proposed access permission probability based on the estimated number of contending users for each service are presented to reduce MAI. The assured priority to the voice and the videophone handoff calls is given through higher access permission probability. And through the proposed code assignment scheme, the voice service can be provided without the voice packet dropping probability in the CDMA/PRMA protocols. The code reservation is allowed to the voice and the videophone services. The low-rate data service uses the available codes during the silent periods of voice calls and the remaining codes in the codes assigned to the voice service to utilize codes efficiently. The high-rate data service uses the assigned codes to the high-rate data service and the remaining codes in the codes assigned to the videophone service. Using the Markov-chain subsystem model for each service including the handoff calls in uplink cellular systems, the steady-state performances are simulated and analyzed. After a round of tests for the examples, through the proposed code assignment scheme and the access permission probability, the Packet CDMA Reservation ALOHA protocol can guarantee the priority and the constant QoS for the handoff calls even at large number of contending users. Also, the data services are integrated efficiently on the multi-rate transmission.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.3
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• pp.83-89
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• 2000

In hydraulic control system turbine and gear motor type flowmeters are widely used to measure the flow rate under steady flow conditions. With the recent growth of interest in the measurement of instantaneous values of unsteady flow rate the test of the transient response of these flowmeters are in some significance. however an unsteady flow rate mea-surment and its calibration method with a fast response and a high accuracy have not beendeveloped. In this research particularly the dynamic characteristics of turbine and gear motor type flowmeters are investigated experimentally and simple mathematical models are proposed. The measured flow rate waveforms are compared with those by remote instan-taneous flow rate measurement method(RIFM) which has been developed by author and used for calibration As the result of frequency response test gain and phase between the measured flow rate waveforms by turbine type flowmeter and those estimated by RIFM are in good agreement up to 70Hz For the gear motor type flowmeter th simulated results by a math-ematical model proposed here agree well with the experiment nearly up to 100Hz. Also it if sound that the pressure drop across the flowmeter is increased in proportion to the frequency of the flow rate variation in a high frequency region of more than 100Hz. It can be explained that the dealy of gear motor type flowmeter in high frequency regionis mainly attributed to a first order delay consisting of the inertia of gears and internal leakage of the gear motor.

• Smart Media Journal
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• v.2 no.4
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• pp.51-59
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• 2013

With increasing transmission speed of backbone networks, it is getting to provide enough available bandwidth. However, the bandwidth is not effectively utilized in volumetric data transfer. This mainly comes from the transmission protocol, TCP, which is used for most applications. TCP is inherently difficult to adapt the available bandwidth because of it's own characteristic of transfer mechanism. UDT is a prominent application level data transfer protocol which is targeting high speed network. In this paper, we propose UDT parallel transfer technologies which is adaptive to network status and then evaluate their performance in two points of view. Firstly, we measure data transfer rate of UDT with rate congestion control methods, and compare them with basic UDT. Secondly, we apply parallel transfer technologies adapted to network status, and measure their performance. Experimental results showed that UDT rate congestion control method outperforms UDT with 106% improvement in RTT 100ms section set with jitter 30ms. In addition, performance of parallel transfer with rate congestion control method showed 107% improvement than that of parallel transfer in RTT 400ms section set with jitter 20ms.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.3
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• pp.47-56
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• 2018

Research was initiated to investigate germination characteristics and germination pattern of 14 herbaceous plant entries used on the road slope during 30 days. An alternative germination condition for 14 herbaceous plant entries required by International Seed Testing Association(ISTA) was applied in the experiment, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$. Significant differences were observed in the first germination rate(0.3%~40.7%)and in the final germination rate(7.7%~93.3%). Days to the first germination(2~8days), days to the 30% germination(2~6days) and days to the peak germination(6~18days) were different among 14 herbaceous plant entries in the study. From this result, we could find out higher final germination rate of 14 herbaceous plant entries in the following order; First, forage crops and cool-season turfgrasses; Second, herbeceous flowers; Third, wild plants. We could also divide germination rate among 14 herbaceous plant entries as 6 groups(I;very high, II;high, III;medium high, IV;medium low, V;low, VI;very low) based on the final germination rate and divide germination speed as 5 groups(A;very fast, B;fast, C;normal, D;slow, E;very slow)based on days to the peak germination. Considering germination characteristics and pattern of 14 herbaceous plant entries Medicago sativa, Lolium perenne, Festuca arundinacea and Cosmos sulphureus were regard as dominating species while Lespedeza cuneata, Silene armeria, Lotus corniculatus var.japonicus, Coreopsis tinctoria and Centaurea cyanus as competitive species following dominating species. However, Chrysanthemum burbankii, Pennisetum alopecuroides, Chrysanthemum boreale., Artemisia princeps var. orientalis and Arundinella hirta were not almost expected to emerge.

• The Journal of Korean Medicine
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• v.33 no.4
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• pp.50-59
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• 2012

Objectives: This study aimed to compare the effects of high frequency electroacupuncture, low frequency electroacupuncture and manual acupuncture on the autonomic nervous system in stroke patients by using a heart rate variability measuring device. Methods: Thirty-nine participants were recruited and each participated in the high frequency electroacupuncture group, low frequency electroacupuncture group, manual acupuncture group and non-acupuncture group. Some participants received needle insertion with 100 Hz stimulation, with 2Hz stimulation and manual stimulation under mental arithmetic stress during 2 sections. Other participants maintained in the supine position without acupuncture under mental arithmetic stress during the 2 sections. Acupuncture needles were directly inserted perpendicularly to the right Liv 3 acupoint followed by delivery of electric pulses to these points for 8 minutes. Heart rate variability was measured 8 minutes before and 16 minutes after acupuncture stimulation by a heart rate variability measuring system. Results: We found a significant elevated HF total power between 1 section and 2 section and between 1 section and 4 section in the non-acupuncture group, between 3 section and 4 section in the 100Hz electroacupuncture group, and between 1 section and 2 section in the manual acupuncture group and with no change in the 2Hz electroacupuncture group. We also found a significant VLF total power between 2 section and 3 section in the 2Hz electroacupuncture group and between 1 section and 4 section and between 2 section and 4 section in the 100Hz electroacupuncture group. All four groups showed no significant differences in other parameters including heart rate mean, low-frequency power, and the ratio of low-frequency power to high-frequency power. Conclusions: This study may be a basis for research about effects of acupuncture and electroacupuncture because the parameters measured, heart rate variability, showed differences according to acupuncture.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.357-366
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• 1998

Brachytherapy is an essential part of radiotherapy for uterine cervical cancer. The low dose rate (LDR) regimen has been the major technique of intracavitary therapy for cervical cancer. However, there has been an expansion in the last 20 years of high dose rate (HDR) machines using Ir-192 sources. Since 1979, HDR brachytherapy has been used for the treatment of uterine cervical cancer in Korea. The number of institutions employing HDR has been increasing, while the number of low dose rate system has been constant. In 1995, there was a total 27 HDR brachytherapy units installed and 1258 cases of patients with cervical cancer were treated with HDR Most common regimens of HDR brachytherapy are total dose of 30-39 Gy at point A with 10-13 fractions in three fractions per week. 24-32 Gy with 6-8 fractions in two fractions per week, and 30-35 Gy with 6-7 fractions in two fractions per week. The average fractionation regimen of HDR brachytherapy is about 8 fractions of 4.1 Gy each to Point A. In Korea, treatment results for HDR brachytherapy are comparable with the LDR series and appears to be a safe and effective alternative to LDR therapy for the treatment of cervical carcinoma. Studies from the major centers report the five-year survival rate of cervical cancer as. 78-86$\%$ for Stage 1, 68-85$\%$ for stage 11, and 38-56$\%$ for Stage III. World-wide questionnaire study and Japanese questionnaire survey of multiple institutions showed no survival difference in any stages and dose-rate effect ratio (HDR/LDR) was calculated to be 0.54 to 0.58. However the optimum treatment doses and fractionation schemes appropriate to generate clinical results comparable to conventional LDR schemes have yet to be standardized. In conclusion, HDR intracavitary radiotherapy is increasingly practiced in Korea and an effective treatment modality for cervical cancer. To determine the optimum radiotherapy dose and fractionation schedule, a nation-wide prospective study is necessary in Korea. In addition, standardization of HDR application (clinical, computer algorithms, and dosimetric aspects) is necessary.

• The Journal of the Korean life insurance medical association
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• v.1 no.1
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• pp.133-139
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• 1984

In the 2,218 healthy cases-male 1,574 female 644-who were conducted serum examination from May 1st 1983 to November 1st 1983 by the medical selection of Dae Han Kyouk life insurance Co., the results which investigated the HBsAg by using the Reverse Passive Hemagglutination(RPHA) method are as follows; 1. The number of 167 from 2,218 cases proved to be positive, showing 7.52%, the number of 143 from 1,574 male positive, showing 9.08%, and the number 24 from 644 female positive, showing 3.73%. The positive rate of the male was indicated by 5.36% higher than that of the female as the former marked 2.4 times higher distribution than the latter. 2) The positive rate by the type of occupations appears as follows; The highest positive rate group is that of discharger from military service in 1983, the number of 70 from 736 persons marking 9.51% and the next is the merchant 8.79%(8/91), employee of a company markes 8.53%(44/516), high school boy 7.69%(19/247), house wife 5.71%(10/210), carrier woman 3.45%(10/290) and the group of the high school girl records the minimum rate of all, 3.13%(4/128). 3. The positive rate by the age group appears as follows; The highest rate group is that of 31 to 35 years, marking 9.80% positive rate, and the next is $26{\sim}30$(9.3%), $21{\sim}25$(8.01%), $41{\sim}45$(6.96%), $36{\sim}40$(6.9%), those below 20(5.99%), 46 to 50 years shows the minimum rate of all(2.94%) Among the male case, 26 to 30 years shows the highest positive rate by 10.59% and female, 31 to 35 years shows the highest rate by 7.89%. 4. The positive rate by the blood type represents as follows; Blood type A shows 7.30%, type B 7.17%, type O 6.11% and type AB indicates 5.88% in order.