• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.7
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• pp.46-56
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• 2002

In this paper, we describe a hardware-software co-verification methodology and environment in developing a mobile station modem chip for cdma2000 1x which is one of the 3rd generation mobile communication standards. By constructing an efficient co-verification environment for a register-transfer-level hardware model and a physical-layer software model combining a channel link simulator and a versatile test-bench, we can drastically reduce both time and cost for developing a complex three-million-gate class system integrated circuit.

• 한국생태학회:학술대회논문집
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• 2002.08a
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• pp.127-131
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• 2002

In order to elucidate the characteristics of standing crop biomass, production and nutrient content of dead bole in mature ecosystem, we surveyed the dynamics of decaying bole of old-aged deciduous forest in 1993 and 2002 in Kwangnung Experimental Forest Station. In addition, we and estimated annual bole production, water content, wood density and nutrient content and compared the results with that of temperate ecosystem. Total dead wood biomass was estimated to be 5.6ton/ha in 1993 and 17.6ton/ha in 2002. Standing dead tree accounted for a total of 1.1ton/ha in 1993 and 4.8ton/ha in 2002, which was 20% and 27% of the sum of dead bole mass in 1993 and 2002, respectively. Annual production of bole biomass was 1.3 ton/ha/yr. These values fall into the low range of dead wood biomass for the mature temperate ecosystems. Tree species composing standing bole was mainly Quercus and Carpinus trees. This bole species composition resembles alive species composition of this forest. Water content of bole increased as positive logarithmically, but wood density of bole decreased as negative exponentially along with the progress of decay. N, P, Ca and Mg concentrations in decaying boles generally increased with decay, except for K. Annual nutrient input via dead bole is 1.6kg/ha/yr for N, 0.04 kg/ha/yr for P. 1.0 kg/ha/yr for K, 1.7kg/ha/yr for Ca and 0.3 kg/ha/yr for Mg, respectively.

• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.890-895
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• 2012

Duration curves describe the percentage of time that a certain water quality (total/fecal coliform (=TC/FC)) or discharge is exceeded. The curves methodology are usually based on daily records and are useful in estimating how many days per year and event will be exceeded. The technique was further applied to estimated TC/FC loading to the Geumho River, using the daily mean flow rate and TC/FC concentration data during January, 2001 and December, 2011 for the Geumhogang6 (=Seongseo water level station) where an automated monitoring station is located in Gangchang-bridge. Low flow of the Seongseo (=11.1 cms) was equivalent to 75.3% on an exceedance probability scale. Load Duration curve for TC/FC loading at the Seongseo was constructed. Standard load duration curve was constructed with the water quality criteria for class III (TC/FC concentration = 5000/1000 CFU/ 100 mL). By plotting TC/FC observed load duration curve with standard load duration curve, it could be revealed that water quality do not meet the desired water quality for 68.8/11.2% on an exceedance probability scale. IF linear correlation between flow rate and coliform concentration is assumed, it can be interpreted that water quality exceed desired criteria when daily average flow rate is over 11.9/109.9 cms.

• The Korean Journal of Ecology
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• v.25 no.4
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• pp.261-265
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• 2002

In order to elucidate the characteristics of standing crop biomass, production and nutrient content of dead bole in mature ecosystem, we surveyed the dynamics of decaying bole of old-aged deciduous forest in 1993 and 2002 in Kwangnung Experimetal Forest Station. In addition, we and estimated annual bole production, water content, wood density and nutrient content and compared the results with that of temperate ecosystem. Total dead wood biomass was estimated to be 5.6ton/ha in 1993 and 17.6 ton/ha in 2002. Standing dead tree accounted for a total of 1.1 ton/ha in 1993 and 4.8 ton/ha in 2002, which was 20% and 27$\%$ of the sum of dead bole mass in 1993 and 2002, respectively. Annual production of bole biomass was 1.3 ton/ha/yr. These values fall into the low range of dead wood biomass for the mature temperate ecosystems. Tree species composing standing bole was mainly Quercus and Carpinus trees. This bole species composition resembles alive species composition of this forest. Water content of bole increased as positive logarithmically, but wood density of bole decreased as negative exponentially along with the progress of decay. N, P, Ca and Mg concentrations in decaying boles generally increased with decay, except for K. Annual nutrient input via dead bole is 1.6 kg/ha/yr for N, 0.04 kg/ha/yr for P, 1.0 kg/ha/yr for K, 1.7 kg/ha/yr for Ca and 0.3 kg/ha/yr for Mg, respectively.

• Journal of the FoodService Safety
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• v.4 no.1
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• pp.35-41
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• 2023

This study was based on the results of the study of 'Cheonyeon and Chunghyun Taste Alley Pilgrimage- Introducing Hidden Restaurants in Our Town', which was adopted as a project to revitalize urban regeneration as part of the Cheonyeon and Chunghyun Urban Regeneration New Deal project. This study was conducted in total of two stages, as a first step, the commercial district of Seodaemun Station was analyzed by analyzing the hashtag (#) mentioned along with the "Seodamun Station Restaurant" on Instagram from 2015 to 2020. As a result of the analysis, it was found to be an office commercial district related to "office workers", and it was found to be a commercial district with the characteristics of "small but certain happiness" where you can find hidden restaurants in front of your house. Based on the characteristics of these commercial districts, five stores utilizing the characteristics of the region were selected and cooking classes were conducted for students of Kyonggi University, who are local residents. The purpose of this study was to revitalize the aging Seoul city and contribute to the formation of positive relationships between local residents and merchants through cooking classes. In addition, the process was produced as digital media content and used as local promotional materials.

• Journal of Environmental Science International
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• v.22 no.2
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• pp.139-149
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• 2013

Anthropogenic increases in greenhouse gas concentrations, primarily through radiative forcing from carbon dioxide, continue to challenge earth's climate. This study quantified $CO_2$ storage and uptake by dominant forest types and age classes in the middle region of Korea. In addition, the role of forest landscapes in reducing atmospheric $CO_2$ against $CO_2$ emissions based on energy consumption was evaluated. Mean $CO_2$ storage and uptake per unit area by woody plants for three forest types and four age classes were estimated applying regression equations derived to quantify $CO_2$ storage and uptake per tree; and computations per soil unit area were also performed. Total $CO_2$ storage and uptake by forest landscapes were estimated by extrapolating $CO_2$ storage and uptake per unit area. Results indicated mean $CO_2$ storage per unit area by woody plants and soils was higher in older age classes for the same forest types, and higher in broadleaved than coniferous forests for the same age classes, with the exception of age class II (11-20 years). $CO_2$ storage by broadleaved forests of age class V (41-50 years) averaged 662.0 t/ha (US$331.0 hundred/ha), highest for all forest types and age classes evaluated. Overall, an increased mean $CO_2$ uptake per unit area by woody plants was evident for older age classes for the same forest types. However, decreased $CO_2$ uptake by broadleaved forests at age class V was observed, compared to classes III and IV with an average of 27.9 t/ha/yr (US$14.0 hundred/ha/yr). Total $CO_2$ storage by woody plants and soils in the study area was equivalent to 3.4 times the annual $CO_2$ emissions, and woody plants annually offset the $CO_2$ emissions by 17.7%. The important roles of plants and soils were associated with 39.1% of total forest area in South Korea, and $CO_2$ emissions comprised 62.2% of the total population. Therefore, development of forest lands may change $CO_2$ sinks into sources. Forest landscape management strategies were explored to maintain or improve forest roles in reducing atmospheric $CO_2$ levels.

• Journal of Korean Society of Forest Science
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• v.90 no.3
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• pp.227-235
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• 2001

This study was conducted to investigate the effects of adjacent stand on the invasion of Robinia pseudoacacia plantations. The results were as follows. 1) Robinia pseudoacacia tended to invade into all directions regardless of the kinds of adjacent stands. But it was estimated that the invasion of Robinia pseudoacacia into adjacent stands could be very difficult, if the layer structure of adjacent stands were well developed. Whereas, it was estimated that Robinia pseudoacacia more rapidly intruded into adjacent stands, if adjacent stands were opened and bared. 2) Robinia pseudoacacia tended to invade into all aspects regardless of the kinds of vegetation units in the adjacent stands. But the dominance class of Robinia pseudoacacia in the adjacent stands showed a little differences among the vegetation units. The dominance class of Robinia pseudoacacia in Quercus aliena community and Quercus serrata community showed low level as + ~2, while the dominance class of Pinus densiflora community, Pinus rigida community, Quercus variabilis community and Quercus acutissima community represented high level as 1~4. Also the dominance class of Isodon inflexus subgroup among three subgroups of Pinus densiflora community showed the lowest level as + ~2.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.3
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• pp.554-561
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• 2017

IoT (Internet of Things) devices are often located in environments where indoor or underground, signals are difficult to reach. In addition, the transmission power is low, the base station should be designed to be able to receive signals even at low reception sensitivity. For this reason, a device having a poor channel condition can be transmitted at a low data rate using a low coding rate or repetition. When the coverage class is divided according to the channel condition and the data rate, the packet length may vary from one coverage class to another, and the performance of the slotted aloha random access may be degraded. We will focus on two methods of using shared-resource and seperate resources among multiple slotted aloha methods. In particular, when devices with different coverage classes use shared resources, performance of a device with a bad channel condition may deteriorate. Conversely, when using separate resources for each coverage class, there is a problem that congestion may occur which increases the number of devices that perform random access to one resource area. In this paper, we propose some methods to overcome this problem. This study is mainly focused on MTC devices, and is considered to be a high possibility of future development.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.432-461
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• 1995

The basic principles in the design of Class II amalgam cavity preparations have been modified but not changed in essence over the last 90 years. The early essential principle was "extension for prevention". Most of the modifications have served to reduce the extent of preparation and, thus, increase the conservation of sound tooth structure. A more recent concept relating to conservative Class II cavity preparations involves elimination of occlusal preparation if no carious lesion exists in this area. To evaluate the ideal ClassII cavity preparation design, if carious lesion exists only in the interproximal area, three cavity design conditions were studied: Rodda's conventional cavity, simple proximal box cavity and proximal box cavity with retention grooves. In this study, MO amalgam cavity was prepared on maxillary first premolar. Three dimensional finite element models were made by serial photographic method. Linear, eight and six-nodal, isoparametric brick elements were used for the three dimensional finite element model. The periodontal ligament and alveolar bone surrounding the tooth were excluded in these models. Three types model(B option, Gap option and R option model) were developed. B option model was assumed perfect bonding between the restoration and cavty wall. Gap option model(Gap distance: $2{\mu}m$) was assumed the possibility of play at the interface simulated the lack of real bonding between the amalgam and cavity wall (enamel and dentin). R option model was assumed non-connection between the restoration and cavty wall. A load of 500N was applied vertically at the first node from the lingual slope of the buccal cusp tip. This study analysed the displacement, 1 and 2 direction normal stress and strain with FEM software ABAQUS Version 5.2 and hardware IRIS 4D/310 VGX Work-station. The results were as followed. 1. Rodda's cavity form model showed greater amount of displacement with other two models. 2. The stress and strain were increased on the distal marginal ridge and buccopulpal line angle in Rodda's cavity form model. 3. The stress and strain were increased on the central groove and a part of distal marginal ridge in simple proximal box model and proximal box model with retention grooves. 4. With Gap option, Rodda's cavity form model showed the greatest amount of the stress on distal marginal ridge followed by proximal box model with retention grooves and simple proximal box model in descending order. 5. With Gap option, simple proximal box model showed greater amount of stress on the central groove with proximal box model with retention grooves. 6. Retention grooves in the proximal box played the role of supporting the restorations opposing to loads.

• Journal of Photoscience
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• v.9 no.2
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• pp.278-280
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• 2002

We have cloned a hydromedusan opsin cDNA and showed that the deduced amino acid sequence of the cytoplasmic loop between helices 5 and 6 (loop 5-6) was clearly different from that reported so far. The amino acid sequence of the loop 5-6 is important on determination of the specificity for the coupled G- protein. To clarify which class of G-protein mediates the phototransduction system in the ocellus of the hydromedusan, we investigated G-proteins expressed in the ocellus. By PCR against the cDNA of the ocellus with primers designed according to the conserved amino acid sequence in G-protein a subunit, we obtained three kinds of cDNA fragments. Based on the sequence similarities, ttwo of them (JGI and JG3) were classified as $G_{i}$ and $G_{q}$, respectively. The other one (JG2) was a new subtype within $G_{*}$ class. Electron microscopic immunocytochemistry with the antiserum against the C-terminal sequence of $G_{q}$ or $G_{t}$ revealed the presence. of the both classes in the ocellus. The similarity of the C-terminal sequence of the JG2 with that of bovine $G_{t}$ suggests that the anti- $G_{t}$ antiserum would bind to JG2. These results suggest the possibility that the hydromedusan rhodopsin decides the specificity for the coupled G-protein by the other domain than the loop 5-6.oop 5-6.5-6.