• Economic and Environmental Geology
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• v.46 no.6
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• pp.485-494
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• 2013

$CO_2$ Monitoring, Mitigation and Verification (MMV) is the essential part in the Carbon Capture and Storage (CCS) project in order to assure the storage permanence economically and environmentally. In large-scale CCS projects in the world, the seismic time-lapse survey is a key technology for monitoring the behavior of injected $CO_2$. In this study, we developed a basic process procedure for 3-D seismic baseline data from the Aquistore project, Estevan, Canada. Major target formations of Aquistore CCS project are the Winnipeg and the Deadwood sandstone formations located between 1,800 and 1,900 ms in traveltime. The analysis of trace energy and similarity attributes of seismic data followed by spectral decomposition are carried out for the characterization of $CO_2$ injection zone. High trace energies are concentrated in the northern part of the survey area at 1,800 ms and in the southern part at 1,850 ms in traveltime. The sandstone dominant regions are well recognized with high reflectivity by the trace energy analysis. Similarity attributes show two structural discontinuities trending the NW-SE direction at the target depth. Spectral decomposition of 5, 20 and 40 Hz frequency contents discriminated the successive E-W depositional events at the center of the research area. Additional noise rejection and stratigraphic interpretation on the baseline data followed by applying appropriate imaging technique will be helpful to investigate the differences between baseline data and multi-vintage monitor data.

• Journal of Chest Surgery
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• v.38 no.6 s.251
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• pp.410-414
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• 2005

There are several options for choosing a graft in CABG, we routinely chose LIMA for LAD and great saphenous vein for other target vessels. To evaluate the posoperative graft patency, we have studied the results using a 16 slices multi-detector computed tomography. Material and Method: From 1995 to 2003, 80 CABG patients who did not complain any event of MACE have been examined by 16-MDCT, mostly in an out patient clinic. Result: There were 61 men and 19 women. MDCT was used as early as 7 days to 9 years post-operatively with a median follow-up period of 6.5 years, and mean follow-up peiod of $31.5\pm25.4$ months. Mean age was $58.4\pm12.6$ years old in men and $61.5\pm17.2$ years old in women. 72180 patients received LIMA to LAD, and all other patients received vein grafts for bypass. The target vessel of vein grafts were 8 in LAD, 47 in RCA, 60 in diagonals, and 61 in obtuse marginals. Among them 42 sequential anastomoses were performed. The mean graft number was $3.1\pm1.8$ grafts. 5 year graft patency rate of each grafts was as followings; $93.1\%$ in LIMA to LAD, $94.9\%$ in vein to diagonals, $92.1\%$ in vein to obtuse marginals, and $79.2\%$ in vein to RCA. Sequential grafting showed better graft patency than the isolated grafting $(95.2\%\;vs\;78.7\~95.0\%)$. Conclusion: In this study, CABG with LIMA and saphenous veins showed satisfactory longterm results. 16-MDCT provided good images for follow-up study after CABG. Additionally, as radiologic tools (64-MDCT, MRI) improve more in the future, they can be used for diagnosing preoperative anatomical coronary disease as well as cardiac functions.

• Geophysics and Geophysical Exploration
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• v.8 no.3
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• pp.224-231
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• 2005

In geophysical field surveys, commercial equipments often fail to resolve the subsurface target or even sometimes fail to be applied because they do not fit to the various field situations or the physical properties of the medium or target. We developed a geophysical measurement system, which can be easily adapted for the various field situations and targets. The system based on PXI with A/D converter and some stand alone equipment such as Network Analyzer was applied to borehole radar survey, borehole sonic measurement and electromagnetic noise measurement. The system for borehole radar survey consists of PXI, Network Analyzer, dipole antennas, GPIB interface is used for PXI to control Network Analyzer. The system for borehole sonic measurement consists of PXI, 24 Bit A/D converter, high voltage pulse generator, transmitting and receiving piezoelectric sensors. The electromagnetic noise measurement system consists of PXI, 24 Bit A/D converter, 2 horizontal component electric field sensors and 2 horizontal and 1 vertical component magnetic filed sensors. The borehole radar system has been successfully applied to detect the width of the artificial tunnel through which the borehole pass and to image buried steel pipe, while the commercial borehole radar equipment failed. The borehole sonic system was tested to detect the width of artificial tunnel and showed a reasonable result. The characteristic of electromagnetic noise was grasped at an urban area with the data from the electromagnetic noise measurement system. The system is also applied to characterize the signal distortion by induction between the electric cables in resistivity survey. The system can be applied various geophysical problems with a simple modification of the system and sensors.

• Korean Journal of Radiology
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• v.22 no.10
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• pp.1658-1670
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• 2021

Objective: To assess the two-year treatment outcomes of chemoembolization with drug-eluting embolics (DEE) for nodular hepatocellular carcinoma (HCC). Materials and Methods: This study was a prospective, multicenter, registry-based, single-arm trial conducted at five university hospitals in Korea. Patients were recruited between May 2011 and April 2013, with a target population of 200. A DC Bead loaded with doxorubicin was used as the DEE agent. Patients were followed up for two years. Per-patient and per-lesion tumor response analysis, per-patient overall survival (OS) and progression-free survival (PFS) analysis, and per-lesion tumor control analysis were performed. Results: The final study population included 152 patients, with 207 target lesions for the per-lesion analysis. At one-month, six-month, one-year, and two-year per-patient assessments, complete response (CR) rates were 40.1%, 43.0%, 33.3%, and 19.6%, respectively. The objective response (OR) rates were 91.4%, 55.4%, 35.1%, and 19.6%, respectively. The cumulative two-year OS rate was 79.7%. The cumulative two-year PFS rate was 22.4% and the median survival was 9.3 months. In multivariable analysis, the Child-Pugh score (p = 0.019) was an independent predictor of OS, and tumor multiplicity (p < 0.001), tumor size (p = 0.020), and Child-Pugh score (p = 0.006) were independent predictors of PFS. In per-lesion analysis, one-month, six-month, one-year and two-year CR rates were 57.5%, 58.5%, 45.2%, and 33.3%, respectively, and the OR rates were 84.1%, 65.2%, 46.6%, and 33.3%, respectively. The cumulative two-year per-lesion tumor control rate was 36.2%, and the median time was 14.1 months. The Child-Pugh score (p < 0.001) was the only independent predictor of tumor control. Serious adverse events were reported in 11 patients (7.2%). Conclusion: DEE chemoembolization for nodular HCCs in the Korean population showed acceptable survival, tumor response, and safety profiles after a two-year follow-up. Good liver function (Child-Pugh score A5) was a key predictor of per-patient OS, PFS, and per-lesion tumor control.

• Journal of Chest Surgery
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• v.38 no.8 s.253
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• pp.551-556
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• 2005

Background: Complete arterial off-pump coronary artery bypass grafting (OPCAB) by sequential anastomoses with one or two arterial grafts provides favorable outcomes. However, problems of insufficient graft length, hypopefusion, kinking of graft, and unfavorable course of graft may be encountered. To solve these problems, we have used different technique with multiple arterial Y composite graft to allow end-to-side rather than sequential anastomoses and evaluated the results of this method. Material and Method: Between February 2003 and October 2004, If patients underwent total arterial OPCAB using multiple arterial V composite grafts with left internal mammary artery (LIMA), radial artery (RA), and right internal mammary artery (RIMA). We divided RA into multiple segments by number of distal target site after measuring of individual proper length and constructed arterial composite graft. One of segments was sutured end-to-side to LIMA and other segment was sutured end-to-side to the previously constructed radial graft. Postoperative graft patency was evaluated in 6f patients by multi-slice computed tomegraphy. Result: An average of $2.5\pm0.6$ arteries and $3.7pm0.7$ distal anastomoses per patient were done. There was no perioperative myocardial infarction, clinical hypoperfusion syndromes, and operative mortality. Postoperative mean CK-MB level was $17.4pm29.7\;IU/L.$Overall graft patency was $99.1\%\;(214/216)(LIMA:\;100\%,\;RA:\;98.4\%,\;RIMA:\;100\%).$ Conclusion: This technique allows total arterial OPCAB without technical problems and provides excellent early clinical results and graft patency. We believe that this technique is more convenient in the obtuse marginal area compared to sequential technique, and helpful in patients who require complex arterial grafting.

• Korean Chemical Engineering Research
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• v.53 no.1
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• pp.31-38
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• 2015

At present, carbon dioxide ($CO_2$) emission, which causes global warming, is a major issue all over the world. To reduce $CO_2$ emission directly, commercial deployment of $CO_2$ separation processes has been attempted in industrial plants, such as power plant, oil refinery and steelmaking plant. Besides, several studies have been done on indirect reduction of $CO_2$ emission from recycle of reducing gas (carbon monoxide or hydrogen containing gas) in the plants. Unlike many competing gas separation technologies, pressure swing adsorption (PSA) and membrane filtration are commercially used together or individually to separate a single component from the gas mixture. However, there are few studies on operation of sequential separation process of multi-component gas which has more than two target gas products. In this paper, process simulation model is first developed for two available configurations: $CO_2$ PSA-CO PSA-$H_2$ PSA and $CO_2$ PSA-CO PSA-$H_2$ membrane. Operation optimization and economic evaluation of the processes are also performed. As a result, feed gas contains about 14% of $H_2$ should be used as fuel than separating $H_2$, and $CO_2$ separation should be separated earlier than CO separation when feed gas contains about 30% of $CO_2$ and CO. The simulation results can help us to find an optimal process configuration and operation condition for separation of multicomponent gas with $CO_2$, CO, $H_2$ and other gases.

• Journal of Environmental Impact Assessment
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• v.24 no.2
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• pp.134-153
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• 2015

When making urban planning, it is important to understand climate effect caused by urban structural changes. Seoul city applies UPIS(Urban Plan Information System) which provides information on urban planning scenario. Technology for analyzing climate effect resulted from urban planning needs to developed by linking urban planning scenario provided by UPIS and climate analysis model, CAS(Climate Analysis Seoul). CAS develops for analyzing urban climate conditions to provide realistic information considering local air temperature and wind flows. Quantitative analyses conducted by CAS for the production, transportation, and stagnation of cold air, wind flow and thermal conditions by incorporating GIS analysis on land cover and elevation and meteorological analysis from MetPhoMod(Meteorology and atmospheric Photochemistry Meso-scale model). In order to reflect land cover and elevation of the latest information, CAS used to highly accurate raster data (1m) sourced from LiDAR survey and KOMPSAT-2(KOrea Multi-Purpose SATellite) satellite image(4m). For more realistic representation of land surface characteristic, DSM(Digital Surface Model) and DTM(Digital Terrain Model) data used as an input data for CFD(Computational Fluid Dynamics) model. Eight inflow directions considered to investigate the change of flow pattern, wind speed according to reconstruction and change of thermal environment by connecting green area formation. Also, MetPhoMod in CAS data used to consider realistic weather condition. The result show that wind corridors change due to reconstruction. As a whole surface temperature around target area decreases due to connecting green area formation. CFD model coupled with CAS is possible to evaluate the wind corridor and heat environment before/after reconstruction and connecting green area formation. In This study, analysis of climate impact before and after created the green area, which is part of 'Connecting green network across the north and south in Seoul' plan, one of the '2020 Seoul master plan'.

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.663-674
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• 2019

Birds are effective ecological indicators but there is no national protocol in place to monitor population dynamics of forest birds in Korea. To support the establishment of future monitoring protocols, we compared the results of two generally used monitoring methods for forest bird surveys in two temperate mixed forests in central Korea. There was no statistical difference in the number of species and individuals detected per unit survey effort when comparing line transects and point counts. The number of species and individuals were higher in a five-minute count than in a three-minute point count, but the total accumulated number of expected observed species showed no difference between the two count durations. The number of observed species and individuals increased in both methods as plot radius or transect width increased, suggesting that multi-layer or multi-band surveys may be useful for quantitative and qualitative objectives. The decreasing number of observed species and individuals after sunrise suggested that bird monitoring should be conducted earlier in the morning, within four hours after sunrise. To detect 70% of the total number of species, 7.0 to 7.6 survey hours, equivalent to 42 three-minute counts (95% confidence interval [CI]: 26 to 61) or 33 five-minute counts (95% CI: 19 to 53) were needed for unlimited radius point counts. On the other hand, 4.8 survey hours, equivalent to 26 line transect counts (95% CI: 15 to 45) using 200-m transects with unlimited width, were required to achieve the same level of species detection. Therefore, the line transect method may be more effective than the point count method, at least in terms of local species richness assessment. For national forest bird monitoring, our data indicated that one or both survey methods can be selected as a basic protocol, based on the goals and scales of monitoring, forest types, and the conditions of the target areas.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.4
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• pp.36-48
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• 2010

The objectives of this study are to research and analyze the positioning of Mt. Back Hwa(白華山) and the characteristics of its neighboring cultural scenery based on the Two Seated Buddah Temple, a small Buddhist temple of Taeul in Taean and to view both landscape geographic codes and religious attractions over Mt. Back Hwa by discussing its expression and meaning for the scenery scattered or nested over this districts. The panoramic view of west shows the character of Mt. Back Hwa as a magnanimity of Buddhist Goddess of Mercy which is viewed as a view point field no less than its location as a landscape target and its singularity as a rocky mountain. The ancient castle, signal beacon post and the small Buddhist temple of Taeul to be read importantly in the old map and SinjeungDongkukyeojiseungram(新增東國輿地勝覽) form the core of place identity, and a number of carve(engrave) letters such as Eopungdae(御風臺), Youngsadae(永思臺), etc. show the prospect of this mountain and monumentality derived from place characteristics. In addition removing of Taeiljeon, a portrait scroll of Dangun, national ancestor makes possible to guess the national status hold by Mt. Back Hwa in advance and to know that it has symbiotic relationship with indigenous religion and shares with the universal locality which have been continued for a long time through a portrait scroll of Dangun enshrined in Samsunggak. More than anything else, however the Rock-carved Buddha Triad in Taean, Giant Buddha of Baekjae era enshrined in the small Buddhist temple of Taeul is not only why Mt. Back Hwa, magnanimity of Buddhist Goddess of Mercy exists but also a signifier. In spite of such a placity, the union ideas of confucianism, buddhism and doctrinism of buddhism prevailed in the Late Joseon Dynasty allows the cultural phenomenon of taoism to be read in the same weight through Ilsogae(一笑溪) and Gammodae(感慕臺) which are mountain stream and pond area respectively centered in the carve letter, 'Taeeuldongcheon(太乙洞天)' constructed in front of the small Buddhist temple of Taeul, the Baduk board type of rock carvings engraved over them and a number of traces of carve letters made by confucian scholars since the Middle of Joseon Dynasty. The reason such various cultural sceneries are mixed in Mt. Back Hwa is in the results of inheritance of religious places and fusion of sprit of the times, and the various type of cultural scenery elements scattered in Mt. Back Hwa are deemed as unique geographic code to understand the multi-layered placity and the characteristics of scenery of Mt. Back Hwa in Taean.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.6
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• pp.334-342
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• 2016

Conventional eco-design has been implemented based only on the environmental aspects of a product. Key components of a product identified from the analysis of the environmental aspects have been the target for improvement in the conventional eco-design. The use of eco-design index (EDI) considering both the environmental and economic aspects, and utility value (UV) of a product can be envisaged as an alternative way of implementing and assessing the eco-design. The objective of this study was to propose the logic of the EDI and apply it to the components for performing printing function of the multi-function printer. The EDI was formulated by quantifying the UV, life cycle environmental impact (LCE) and life cycle cost (LCC) of the components of a product, here components of the printer. Of the eight components investigated, roller was identified as the best performing consumable in both the environmental and economic aspects. However, its UV was the lowest among the eight. The EDI of the roller was mere $4^{th}$ in ranking out of the eight. Transfer belt ranked $8^{th}$ and $5^{th}$ in the environmental and economic aspects, respectively, while $2^{nd}$ in the utility value with its EDI ranked $3^{rd}$. This indicates that not only the environmental aspects but also economic and utility value aspects should be considered when identifying the key components for improvement in the eco-design.