• Journal of Radiation Protection and Research
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• v.28 no.1
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• pp.59-63
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• 2003

Purpose : Measurement of transmission dose is useful for in vivo dosimetry of QA purpose. The objective of this study is to develope an algorithm for estimation of tumor dose using measured transmission dose for open radiation field. Materials and Methods : Transmission dose was measured with various field size (FS), phantom thickness (Tp), and phantom chamber distance (PCD) with a acrylic phantom for 6 MV and 10 MV X-ray Source to chamber distance (SCD) was set to 150 cm. Measurement was conducted with a 0.6 cc Farmer type ion chamber. Using measured data and regression analysis, an algorithm was developed for estimation of expected reading of transmission dose. Accuracy of the algorithm was tested with flat solid phantom with various settings. Results : The algorithm consisted of quadratic function of log(A/P) (where A/P is area-perimeter ratio) and tertiary function of PCD. The algorithm could estimate dose with very high accuracy for open square field, with errors within ${\pm}0.5%$. For elongated radiation field, the errors were limited to ${\pm}1.0%$. Conclusion : The developed algorithm can accurately estimate the transmission dose in open radiation fields with various treatment settings.

• Current Photovoltaic Research
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• v.5 no.3
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• pp.95-99
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• 2017

The interconnecting shingled solar cells method shows extremely high ratio active area per total area and has the excellent potential for high power PV (photovoltaic). Compared to the conventional module, it can have much more active area due to busbar-free structure. The properties of ECA (electrically conductive adhesives) are significant to fabricate the shingled array PV since it should be used in terms of electric and structural connection. Various ECA were tried and characterized to optimize the soldiering conditions. The open circuit voltage of shingled array cells showed a three-fold increase and efficiency was also increased by 1.63%. The shingled array cells used in CE3103WLV showed the highest power and in CA3556HF the lowest curing temperature and very fast curing time.

• Journal of the Korean Society of Safety
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• v.23 no.5
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• pp.61-66
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• 2008

It is important to calculate the exact crack opening area in the cracked pipe subjected to axial force and bending moment. Among many solutions for obtaining the crack opening displacement, Paris-Tada's expression, which is derived from energy method, is open used in fracture analysis for piping crack problems because of its simplicity. But Paris-Tada's equation has conservativeness when radius over thickness ratio(R/t) is ten or less, for it is based on the stress intensity factor solution having a compliance function derived from a simple shell theory. In this paper we derived a new expression using a different stress intensity factor solution which is able to consider the variation of compliance through wall thickness in a cracked pipe. Conservativeness of both equations was examined and compared to finite element analysis results. Conservativeness of the new equation is decreased when R/t > 10 and increased slightly when R/t < 10 compared with Paris-Tada's. But Both equations were highly conservative when R/t < 10 compared with finite element analysis results.

• 한국해양학회지
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• v.24 no.1
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• pp.15-28
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• 1989

A study on quantitative phytoplankton samples, hydrographic conditions (temperature, salinity, dissolved oxygen), and nutrients has been performed in the southern waters of the Korean East Sea in early spring. Phytoplankton community showed close correlation with hydrographic conditions. This study area could be divided into three phytohydrographic regions; 1) East Korean Warm Water Region (a branch of Tsushima Current), 2) North Korean Cold Water Region, and 3) offshore water region not affected by other two water regions. Vertical distribution of phytoplankton is dependent upon stability of water column and nutrient concentration. Nutrient concentration shows characteristic distribution according to water masses. N/P ratio of ca. 3 in surface layer indicates that nitrogen is the major limiting nutrient in this area. N/P removal ratio was 12.54 ($r^2$ = 0.96), consistent with the Redified ratio. Primary nitrite maxima at the nitracline depths are thought to be formed by phytoplankton exudation. Secondary nitrite maximum was observed in coastal area with dissolved oxygen content of >5.2 ml/l much higher than <0.25 ml/l in other areas. The mechanism of secondary maximum is different from that of other regions, and whether it may be due to in situ degradation of organic matter by bacterial activity is still open to discuss.

• Journal of Korean Society of Rural Planning
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• v.25 no.3
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• pp.115-128
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• 2019

The A1B scenario predicts that the mean air temperature of South Korea will rise up to $3.8^{\circ}C$ by 2071. However, the effects of ecosystem services are declining because of various environmental problems, including climate change, land use change, stream intensification, non-point pollution, and untreated garbage. Moreover, horticultural sites which have various ecosystem services suffer highly absorbed heat from the heat island phenomenon associated with climate change. Therefore, we analyzed the heat island phenomenon occurring in an protected horticulture estimated area in Saemanguem, South Korea. Using an advanced measurement method, we examined the air temperature change derived from water channels as well as open spaces. The CFD analysis of coverage ratio 85% design showed wind speed of 2.09 m/s and temperature of $38.07^{\circ}C$. At a coverage ratio of 70%, the wind speed was improved to 2.61 m/s and the temperature was improved to $36.89^{\circ}C$. In Alternative 2 with wetlands and trees, the wind speed was 2.71 m/s and the temperature was $35.90^{\circ}C$. When the coverage ratio decreases to 55%, the wind speed increases showing 3.06 m/s and the temperature decreases showing $35.18^{\circ}C$.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.165-171
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• 2017

Reading Pen is used mostly in educational purpose, yet its possibility is great as an input device for various IT devices. Reading Pen recognizes tiny dot patterns printed in papers, converts the patterns to corresponding codes, and plays audio contents that match the codes. Recognizing dot patterns and converting to the codes are the main function of Reading Pens, on which we focus and propose a novel algorithm. Such technology is never open to public and this paper is the first open attempt in this area. We test the algorithm and obtain 85% recognition ratio.

• Korean Journal of Remote Sensing
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• v.16 no.1
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• pp.37-45
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• 2000

Since being launched for ocean observing in 1997, the SeaWiFS sensor has supplied data on ocean chlorophyll distribution and environmental conditions of the atmosphere. Until now, a lot of SeaWiFS data have been archived and utilized for ocean monitoring and land observation. The SeaWiFS sensor has 1km spatial resolution, therefore, it is difficult to obtain data at the coastal zone. Since atmospheric correction algorithms at the coastal area have not been confirmed for chlorophyll algorithm, the ocean color data analysis for coastal zone is not common. In particular, domestic coastal areas have high suspended sediments concentrations and higher absorption influence of colored dissolved organic matter (CDOM), released from in-land, than open-sea. Thus, a useful algorithm for analysis of chlorophyll distribution in domestic coastal areas has not been developed. In this study, empirical algorithms, using data from the ocean color sensor, were developed for monitoring of chlorophyll distribution of coastal areas. In the process of the development of the algorithms, we can find that the red band (665nm) should be used for analyzing of domestic coastal areas near the Yellow Sea.

• Archives of Craniofacial Surgery
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• v.22 no.2
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• pp.85-92
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• 2021

Background: Patients with secondary deformities associated with unilateral cleft lip and nose might also suffer from nostril stenosis due to a lack of tissue volume in the nostril on the cleft side. Here, we used full-thickness skin grafts (FTSGs) to reduce nostril stenosis and various methods for skin volume augmentation. We compared the changes in the symmetry of both nostrils before and after surgery. Methods: From February 2016 to January 2020, 34 patients underwent secondary cheiloplasty and open rhinoplasty for secondary deformities of the unilateral cleft lip and nose with nostril stenosis. FTSG was used on the nostril floor, nasal columella, and alar inner lining. The measured nasal profile included the nostril surface, nostril circumference, width of the nostril floor, and distance from the alar-facial groove to the nasal tip. The "overlap area," which was defined as the largest overlapping area when the image of the cleft nostril was flipped to the left and right and overlaid on the image of the normal side nostril, was also calculated. The degree of symmetry was evaluated by dividing the value of the cleft side by that of the normal side of each measured profile and expressed as "ratios." Results: The results of all profile ratios, except for the nostril floor width, became significantly close to 1, which represents full symmetry. The overlap area ratio improved from 62.7% to 77.3%, meaning that the length and width of the nostril as well as the overall shape became similar (p< 0.05). Conclusion: When performing cleft rhinoplasty with nostril stenosis, FTSG is useful to achieve symmetry in the nostril size and shape. Skin grafting is simpler to perform than the other types of local flap, and the results are generally satisfactory.

• Journal of Environmental Impact Assessment
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• v.24 no.3
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• pp.287-299
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• 2015

If the Nakdong River estuary is to be sustainable, land use management practices need to consider bird habitat requirements, especially given that the area serves as an important migratory bird sanctuary. In this study, bird habitats found in the Nakdong River estuary were classified into 11 different types including Phragmites australiss, mud flat, farmland, open surface in freshwater, sand bar, riparian forest, Scirpus planiculmis, waterway, construction, grasslands, and open surface in sea or brackish water. Taking into consideration the regional characteristics, habitat properties, and landscape indices, a total of 12 study sites were analyzed. Mud flat, construction, farmland, and P. australis account for 80% of the total land area. The high area ratio of construction and farmland to other types of habitat revealed a high amount of historical human activity and intervention in the area. Both patch numbers as well as patch density were high in West Nakdong River, Samrak Waterfront, Maekdo River, and Daejeo Floodgate, with these areas showing the greatest fragmentation as well. Total numbers of species and individuals had a positive correlation with the area and the number of habitat types. Findings suggest that protecting the habitat area, especially in S. planiculmis, is the most important factor for bird habitat management and that future development could result in habitat loss, having a profoundly adverse impact on bird populations. Therefore, it is important that the total area should be carefully protected by land use regulations in order to ensure that the Nakdong River estuary maintains its functional integrity as a migratory bird sanctuary.

• Journal of Korea Port Economic Association
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• v.32 no.4
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• pp.127-147
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• 2016

This study proposes the improvement scheme of the current lease rate assessment system (2003~2014), as a major problem solving area, for the Terminal Operating Company (TOC)'s wharf since the introduction of the TOC system in 1997. The study considers the reform system using three criteria: standardization, simplification, and fairness. The final alternative presented by the study adopts the lease rate assessment system, which newly reflects changes of facilities' property values for aprons, combining it with the related fees of the Korean seaport dues for open storage yards, warehouses (shed), passages, buildings and lands within leased facilities. The proposal anticipates that the new system will not only minimize stakeholders' confusion, but also resolve the main problems within the current system. The study, further, introduces the adjustment ratio, which will make the new lease rate of the apron equal to the current lease rate of a berth, for the individual TOC's wharf, in order to prevent a sharp increment in the lease rate of the apron. This is because the government or port authorities as lessors, need to give priority to lightening the burden of TOC's costs under the deteriorating business environment such as the slowdown in port throughputs' growth. This study makes a contribution by suggesting a new lease rate assessment system for the TOC's wharf, reflecting the value of property as well as leading to its simplification and standardization. Additionally, it may lead to the improvement of fairness by applying the same rate to all leased wharfs for the lease rates of open storage yards, warehouses (shed) and passages. However, it has a limitation that hinders the fairness: the lease rate for the apron cannot be imposed in proportion to the leased area, by applying the individual adjustment ratios. In the future, those adjustment ratios should be, gradually, rationalized to be the same target ratio (0.5) for each wharf, following an improvement in the terminal operating business environment.