• Journal of KIISE:Information Networking
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• v.31 no.1
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• pp.37-52
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• 2004

Broadcast has been often used to disseminate the frequently requested data efficiently to a large volume of mobile units over a single or multiple channels. Since the mobile units have limited battery power, the minimization of the access time for the broadcast data is an important problem. There have been many research efforts that focus on the improvement if the broadcast techniques by providing indexes on the broadcast data. In this paper, we studied an efficient index allocation method for the broadcast data over multiple physical channels, which cannot be coalesced into a single high bandwidth channel. Previously proposed index allocation techniques either require the equal size of index and data or have a performance degradation problem when the number of given physical channels is not enough. These two problems will result in the increased average access time for the broadcast data. To cope with these problems, we propose an efficient tree- structured index allocation method for the broadcast data with different access frequencies over multiple physical channels. Our method minimizes the average access time for the broadcast data by broadcasting the hot data and their indexes more often than the less hot data and their indexes. We present an in-0e0th experimental and theoretical analysis of our method by comparing it with other similar techniques. Our performance analysis shows that it significantly decrease the average access time for the broadcast data over existing methods.

• Journal of Food Hygiene and Safety
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• v.13 no.3
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• pp.252-257
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• 1998

Bamboo salt has been used as a traditional remedy for gastric ulcer and gastro-intestinal disorders. It is produced by baking the salt packed in bamboo cylinder nine times under the fire of pine tree. Three of commercially available bamboo salt products (bamboo salt A, B, and C) were characterized by qualitative and quantitative analyses using inductively coupled plasma (ICP) spectrometer, ion chromatograph (IC), X-ray diffractometer (XRD), and electron microscope (EM). Compared with crude salt, the contents of iron, silicon, potassium, and phosphate in the bamboo salt products were higher whereas the sulfate content was lower. Water-insoluble fraction of bamboo salts contained the following compounds; MgO, $SiO_2,\;Mg_2Si0_4,\;and\;CaMgSi0_4$. The study on the microscopic structures of the bamboo salts were shown to have smooth surface and fused shape compared with crude salt. Among the three bamboo salt products, product A was used to test a possible inhibitory effect on gastric acid secretion. Each test material (bamboo salt A, crude salt, and reagent-grade NaCl) was given orally to Sprague-Dawley rats at doses of 0.2, 1.0, and 2.0 g/kg for 28 days before pyrolus ligation. Twenty four hours after the last administration of the test materials, volume, pH, total acidity, and pepsin activity of gastric juice were measured by the Shay-ligation method. No significant differences were observed in the secretion of gastric acid between treated groups (bamboo salt-, crude salt- and reagent-grade NaCI-treated groups) and control group (distilled water-treated group). This result demonstrated that bamboo salt did not exert anti-ulcer activities in experimental animals used in the present study.

• Korean Journal of Head & Neck Oncology
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• v.16 no.2
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• pp.167-171
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• 2000

Objectives: To compare the outcomes of treatment with a focus on the effectiveness of the two primary techniques of radiation used for treating parotid gland malignancies. Materials and Methods: A retrospective analysis of 70 patients with parotid gland cancer treated between 1981-1997. Radiation was delivered through an ipsilateral field of high energy electron and photon in 37 patients(52.9%). Two wedge paired photon was used to treat in 33 patients(47.1%). The median dose was 60 Gy, typically delivered at 1.8-2.0Gy per fraction. The median follow-up times for surviving patients was 60 months. Results: The overall and disease free 5 year survival rates were 71.6% and 69.5%, respectively. Wedge paired photon and photon-electron treatment disease tree 5 year survival rates were 61.1% and 80.5%, respectively. Overall local failure rate was 18.6%. Local failure rate of wedge paired photon technique was higher than that of mixed beam technique. Late complication rate was 37.1%, but most of them were mild grade. Conclusion: Techniques of radiation were associated with local control. The technique of using an ipsilateral field encompassing the parotid bed and treated with high energy electrons often mixed photons was effective with minimal severe late toxicity. To irradiate deep sited tumors, we consider 3-D conformal treatment plan for well encompassing the target volume.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.5
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• pp.76-87
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• 2014

Today the energy consumption of ICT networks is about 10% of the worldwide power consumption and is predicted to increase remarkably in the near future. For this reason, this paper studies energy saving strategies assuring the network-level QoS. In the strategies, the energy consumption of NIC(network interface card) on both endpoint of links decreases by selecting links and making them sleep when the total traffic volume of the IP network is lower than a threshold. In this paper, we propose a heuristic routing algorithm based on so-called delegating/delegated routers, and evaluate its characteristics using computer simulation considering network-level QoS. The selection of sleep links is determined in terms of the number of traffic paths (called min_used path) or the amount of traffics(called min_used traffic) through those kinks. To our experiment, the min_used traffic method shows a little better energy saving but the increased path length compared to the min_used path method. Those two methods have better energy saving characteristics than the random method. This paper confirms that the delegating/delegated router-based routing algorithm results in energy saving effects and sustains network-level QoS in IP networks.

• Korean journal of applied entomology
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• v.42 no.4
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• pp.315-321
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• 2003

Larval entrance and adult emergence holes of Japanese pine sawyer (Monochamus alternatus), primary vector of pinewood nematode (Bursaphelenchus xylophilus), were measured in dead pine logs from 1999 to 2002. Their distributions within pine log were also analyzed. More numbers of entrance and emergence holes were distributed on crown than trunk part as 56.2 and 27.7 holes/m$^2$, respectively Higher proportions of entrance (27.5％) and emergence holes (22.4%) were distributed on the log with 8 to 10 cm diameter; the larger or the smaller logs had fewer holes. Surface area of entrance hole was 65.8 $\textrm{mm}^2$ and diameter of emergence holes was 7.0 mm in average. Average depth of pupal chamber was 24.8 mm from surface to the bottom of the chamber, and its volume ranged from 200 to 2.000 ㎣ Average distance between entrance and emergence holes on bark surface was 3.3 cm. Gallery length from the beginning of entrance hole to the end of emergence hole was 46.2 mm.

• Journal of Korea Foresty Energy
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• v.24 no.2
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• pp.10-15
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• 2005

This study was achieved by purpose to measure carbon emissions by conversion of forest land in Korea to correspond to UNFCCC. The conversion of forest land data extracted in forest basis statistical data during the latest 5 years from 2000 to 2004, and biomass carbon emissions used biomass extension factor by forest types and carbon conversion factor. During the latest 5 years, the forest land of the annual means about 7,200ha was conversed as other expenditure and tree volume of the annual mean about $212,000m^3$ was felled. It was calculated that total biomass carbon emissions by conversion of the forest land emits annual mean 105,000tC during the latest 5 years. Biomass carbon emissions by forest types was calculated that coniferous forest emits 54,000tC and deciduous forest emits 51,000tC. It was calculated that carbon emissions per ha by conversion of the forest land emits annual mean 14.4tC/ha during the latest 5 years. Seeing by forest types, coniferous forest emits 13.3tC/ha and deciduous forest emits 18.5tC/ha. Therefore, it was shown that deciduous forest emits more carbon per unit area than coniferous forest.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.793-799
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• 2016

This study examined Platanus orientalis and Ulmus davidiana planted in downtown parks to identify the correlations among microclimatic factors such as temperature in the crown, air flow, and wind speed. For the field survey, measurements were taken at 1 hour intervals from 09:00 am to 06:00 pm in August. For the measurement of microclimatic factors, data on temperature, light intensity, air flow, and wind speed were collected using a quantum sensor (PAR Quantum Sensor SKP215), a precision thermometer (Pt1000-Sensor), and a combination anemometer (1467 G4 & HG4). The results of the analysis demonstrated that both Platanus orientalis and Ulmus davidiana, showed a greater cooling effect inside the crown as compared with the outside temperature. The cooling effect inside the crown was more evident with air flow and wind speed factors. With relation to wind, the inner temperature of the crown of Platanus orientalis decreased due to air flow while that of Ulmus davidiana decreased due to wind speed. With no wind, the average variation in temperature inside the crown was $-0.9^{\circ}C$ for Ulmus davidiana and $-0.958^{\circ}C$ for Platanus orientalis, indicating that Platanus orientalis was relatively more effective in lowering the temperature of the planting space than Ulmus davidiana. This study is significant because it shows that different tree species have different effects on the microclimate and that factors affecting the formation of the microclimate of trees may vary with species. Further studies on species other than broad leaf trees, such as evergreen trees and shrubs, are required in order to plan the distribution of landscaping trees that are effective in regulating the microclimate within urban green spaces.

• KSBB Journal
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• v.11 no.1
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• pp.71-76
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• 1996

Studies were carried out to examine some factors affecting the supercritical carbon dioxide extraction of taxol from the bark of Taxus cuspidata using a continuous packed bed extractor. The factors investigated in this study were pressure, temperature, volume of carbon dioxide, and co-solvent. It was found out that the amount of taxol extracted was not significantly affected by the operating pressure in the absence of a co-solvent although it increased by about 20% at 5500 psig. With $24\ell$ of carbon dioxide the saturated amount of taxol was extracted at 318K and 5500psig. Methanol was found to be the most effective co-solvent in terms of amount of taxol extracted among six different co-solvents used. When methanol was used as a co-solvent the effect of operating pressure became significant; approximately 50% increase in the amount of taxol extracted was observed at 3000 psig as compared to at 2500 or 3500psig. The optimum methanol concentration in supercritical fluid was 13% (w/w)at 308K, 3000psig.

• Journal of Korean Society of Forest Science
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• v.77 no.2
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• pp.186-192
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• 1988

This study was carried out to estimate the stand form factor that is necessary to estimate stand volume by STRAND method among plotless sampling methods. The data measured for this study were based on the 380 sample plots from Larix leptolepis and 358 sample plots from Pinus koraiensis which were distributed in the region of Kyeongi, Kangweon, Chungbuk, Chungnam, Chun-buk and Kyeongbuk. 1. Stand form factor was highly correlated with in the following order, stand form height, stand average height, average diameter, stand age, distance of stem, and basal area height. 2. The best fitted equation of stand form factor of above two tree species were presented in table 3. 3. Stand form factor tables using estimated equations on the table 3 were prepared and presented in table 4, 5(Larix leptolepis), 6, 7(Pinus karaiensis). 4. The relatioinships between estimated value and actual value were Y=bx, where b approached nearly 1.0, and there were not any significant differences between them. 5. The percentages of estimated error on stand form factor table were ranged from 2.39% to 4.15% in Larix leptolepis and from 1.73% to 2.50% in Pinus koraiensis. Therefore, the stand form factor could be exactly estimated by use of these tables.

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.438-445
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• 1999

The concentrations of some ions ($NO{_3}^-$, $Ca^{2+}$, $Mg^{2+}$, $NH{_4}^+$) in soil solution collected by zero tension lysimeter in mature Pinus rigida plantations in Goksung, Jeonranam-do were measured at two soil depths (10cm and 30cm) following various levels of cutting intensity treatment (uncut, $6m{\times}50m$, $10m{\times}50m$, $20m{\times}50m$ strip crearcutting) three times (July 6. July 30, and August 4) between June 20 and August 4 1998. The ion concentrations in the soil solution were significantly different among sampling times, while the concentrations were not different among cutting levels or sampling depths. The ion concentrations in the soil solution decreased in the order of $NO{_3}^-$ > $Ca^{2+}$ > $Mg^{2+}$ > $NH{_4}^+$ and the mean concentration was 3.60mg/L for $NO{_3}^-$, 1.7mg/L for $Ca^{2+}$, 0.5mg/L for $Mg^{2+}$, and 0.04mg/L for $NH{_4}^+$ respectively. These ion concentrations except for $NH{_4}^+$ ion were negatively correlated with the volume of collected soil solutions (r=-0.31~-0.41). The results suggest that the change of nutrient concentrations in the soil solution collected from the P. rigida plantations was related to the temporal input patterns of precipitation rather than the cutting intensity.