• Progress in Medical Physics
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• v.12 no.1
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• pp.41-50
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• 2001

The quantification analysis of renal scintigraphy is strongly affected by the location, shape and size of region of interest(ROI). When ROIs are drawn manually, these ROIs are not reproducible due to the operators' subjective point of view, and may lead to inconsistent results even if the same data were analyzed. In this study, the effect of the ROI variation on the analysis of renal scintigraphy when the ROIs are drawn manually was investigated, and in order to obtain more consistent results, methods for automated ROI definition were developed and the results from the application of the developed methods were analyzed. Relative renal function, glomerular filtration rate and mean transit time were selected as clinical parameters for the analysis of the effect of ROI and the analysis tools were designed with the programming language of IDL5.2. To obtain renal scintigraphy, $^{99m}$Tc-DTPA was injected to the 11 adults of normal condition and to study the inter-operator variability, 9 researchers executed the analyses. The calculation of threshold using the gradient value of pixels and border tracing technique were used to define renal ROI and then the background ROI and aorta ROI were defined automatically considering anatomical information and pixel value. The automatic methods to define renal ROI were classified to 4 groups according to the exclusion of operator's subjectiveness. These automatic methods reduced the inter-operator variability remarkably in comparison with manual method and proved the effective tool to obtain reasonable and consistent results in analyzing the renal scintigraphy quantitatively.

• The Korean Journal of Nuclear Medicine
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• v.34 no.6
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• pp.456-464
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• 2000

Purpose: To evaluate the effect of acupuncture on regional cerebral blood flow (rCBF) at acupoints suggested by oriental medicine to be related to the treatment of cerebrovascular diseases. Materials and Methods: Rest/acupuncture-stimulation Tc-99m ECD brain SPECT using a same-dose subtraction method was performed on 54 normal volunteers (34 males, 20 females, age range from 18 to 62 years) using six paradigms: acupuncture at acupoints GV. 20, GV. 26, LI. 4, ST. 36 and SP. 6. In the control study, needle location was chosen on a non-meridian focus 1 cm posterior to the right fibular head. All images were spatially normalized, and the differences between rest and acupuncture stimulation were statistically analyzed using SPM$^{(R)}$ for Windows$^{(R)}$. Results: Acupuncture applied at acupoint GV. 20 increased rCBF in both the anterior frontal lobes, the right frontotemporal lobes, and the left anterior temporal lobe and the left cerebellar hemisphere. Acupuncture at GV 26 increased rCBF in the left prefrontal cortex. Acupuncture at LI. 4 increased rCBF in the left prefrontal and both the inferior frontal lobes, and the left anterior temporal lobe and the left cerebellar hemisphere. Acupuncture at ST. 36 increased rCBF in the left anterior temporal lobe, the right inferior frontal lobes, and the left cerebellum. Acupuncture at SP. 6 increased rCBF in the left inferior frontal and anterior temporal lobes. In the control stimulation, no significant rCBF increase was observed. Conclusion: The results demonstrated a correlation between stimulation at each acupoint with increase in rCBF to the corresponding brain areas.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.4
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• pp.176-184
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• 2011

Cold air on sloping surfaces flows down to the valley bottom in mountainous terrain at calm and clear nights. Based on the assumption that the cold air flow may be the same as the water flow, current models estimate temperature drop by regarding the cold air accumulation at a given location as the water-like free drainage. At a closed catchment whose outlet is blocked by man-made obstacles such as banks and roads, however, the water-like free drainage assumption is no longer valid because the cold air accumulates from the bottom first. We developed an empirical model to estimate quantitatively the effect of cold pool on nocturnal temperature in a closed catchment. In our model, a closed catchment is treated like a "vessel", and a digital elevation model (DEM) was used to calculate the maximum capacity of the cold pool formed in a closed catchment. We introduce a topographical variable named "shape factor", which is the ratio of the cold air accumulation potential across the whole catchment area to the maximum capacity of the cold pool to describe the relative size of temperature drop at a wider range of catchment shapes. The shape factor is then used to simulate the density profile of cold pool formed in a given catchment based on a hypsometric equation. The cold lake module was incorporated with the existing model (i.e., Chung et al., 2006), generating a new model and predicting distribution of minimum temperature over closed catchments. We applied this model to Akyang valley (i.e., a typical closed catchment of 53 $km^2$ area) in the southern skirt of Mt. Jiri National Park where 12 automated weather stations (AWS) are operational. The performance of the model was evaluated based on the feasibility of delineating the temperature pattern accurately at cold pool forming at night. Overall, the model's ability of simulating the spatial pattern of lower temperature were improved especially at the valley bottom, showing a similar pattern of the estimated temperature with that of thermal images obtained across the valley at dawn (0520 to 0600 local standard time) of 17 May 2011. Error in temperature estimation, calculated with the root mean square error using the 10 low-lying AWSs, was substantially decreased from $1.30^{\circ}C$ with the existing model to $0.71^{\circ}C$ with the new model. These results suggest the feasibility of the new method in predicting the site-specific freeze and frost warning at a closed catchment.

• 한국해양학회지
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• v.14 no.1
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• pp.15-25
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• 1979

A study on field bioassay test using four species of commercially important shellfish was carried out to assess the effect of pollutants and determine the extent of marine environmental pollution of the Masan Bay from 9 to 15 August 1978. Water quality analysis and planktological examination of sea water were made during the experiment and the examination gave the following results. The water temperature was so high at 31.7$^{\circ}C$ in maximum and rather subject to change on weather condition of the land than on the effect of the water mass from outer bay. The range of DO,COD and SS at the stations were 0.3-7.08cc/l, 0.07-3.31ppm and 5.5-117ppm, respectively with the high values of COD and SS at the stations 7 and 1. The concentrations of the dissolved inorganic nitrogen in sea water, NH$\sub$4/-N, NO$\sub$2/-N, NO$\sub$3/-N, and PO$\sub$4/-P were 18.90-99.80, 2.48- 19.60, 13.00-39.00 and 1.04-14.0$\mu\textrm{g}$ at/l, respectively with decrease of their values in the outer part of the Bay. The high values mentioned above were caused by the sewage and industrial activities. The effects of organic waste are increased oxygen demand, nutrient concentration, turbidity and a higher input of pathogens, leading to structural changes in the marine ecosystems and to a considerable hazard to public health. The percentage composition of phytoplankton standing crop between diatom and dinoflagellate was characterized by making a difference between the two groups in respect of location: a decrease of diatom and a increase of dinoflagellate in numerical abundance toward inner part from outer part of the bay. Namely phytoplankton organisms were composed of 80% of diatom and 20% of dinoflagellate in outer bay, on the contrary, only 4% of diatom and 96% of dinoflagellate occupied by 94% of prorocentrum micans known as tolerant species to polluted reaas in the inner bay. On the occurrence and composition of zooplankton, there are two significant communities in the bay:one is characterized by the predominance of Oithona nana and the other by Favella sp They were composed of a range from 84% to 90% of the total organisms and monotonously constituted of themselves only at most inner station 3 even small numbers. From the results mentioned above, Oithona nana, Favella and prorocentrum micans recommed themselves as valuable indicators for judging the extent of the marine pollution.During the period of the biossays Mytilus edulis showed the highest mortality and Tapes japonica the lowest one between the four test species. The highest death rate by stations was found at most inner stations 3'and 4near Masan Free Export Zone with the most sensitive response and the lowest one occured at outer station 13 where no death specimen of oyster and arkshell was found during the whole test period.As for mussel,85 percent death rate appeared after 72 hours and 100percent rate after 120hours at station 4. It was found that the significant high mortality of the test shellfish mentioned above was caused by severe pollution with mainly organic pollutants from domestic sewage and industrial wastes from the results of too much higher concentrations of dissolved inorganic nitrogen especially ammonia-N,COD,SS and lack of dissolved oxygen,and furthermore occurrence and abundance composition of Prorcentrum,Favella and Oithona nana by stations, valuable indicator species of coastal pollution by orgnic and boilogical pollutants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.85-92
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• 2008

An RIL population from a Shinpaldalkong2/GC83006 cross was employed to identify quantitative trait loci (QTL) associated with agronomic traits in soybean. The genetic map consisted of 127 loci which covered about 3,000cM and were assigned into 20 linkage groups. Phenotypic data were collected for the following traits; plant height, leaf area, flowering time, pubescence color, seed coat color and hilum color in 2005. Seed weight was evaluated using seeds collected in 2003 to 2005 at Suwon and in 2005 at Pyeongchang and Miryang sites. Three QTLs were associated with 100-seed weight in the combined analysis across three years. Among the three QTLs related to seed weight, all GC83006 alleles on LG O ($R^2\;=\;12.5$), LG A1 ($R^2\;=\;10.1$) and LG C2 ($R^2\;=\;11.5$) increased the seed weight. A QTL conditioning plant height was linked to markers including Satt134 (LG C2, $R^2\;=\;25.4$), and the GC83006 allele increased plant height at this QTL locus. For two QTLs related to leaf area, 1aM on LG M ($R^2\;=\;10.0$) and laL on LG L ($R^2\;=\;8.6$), the Shinpaldalkong2 alleles had positive effect to increase the leaf area. Satt134 on LG C2 ($R^2\;=\;41.0$) was associated with QTL for days to flowering. Satt134 (LG C2) showed a linkage to a gene for pubescence color. Satt363 (LG C2) and Satt354 (LG I) were linked to the hilum color gene, and Sat077 (LG D1a) was linked to the seed coat color. The QTL conditioning plant height was in the similar genomic location as the QTLs for days to flowering in this population, indicating pleiotropic effect of one gene or the tight linkage of several genes. These linked markers would be useful in marker assisted selection for these traits in a soybean breeding program.

• Management & Information Systems Review
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• v.37 no.3
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• pp.83-113
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• 2018

The purpose of this study to empirically examine a smart work investment and job performance by change resistance. Firstly, There investigates mediating role of the communication between the smart work investment and the job performance. Secondly, It will identify the job productivity differences through a level of organizational change resistance that reduced smart work investment. The smart work is to provide the flexibility of time and location and is a working method to improve a work productivity of organization members. The introduction of smart work means the adoption of new organizational culture, institution and technology and requires a novel change of a custom and pattern on existing organization culture and institution because of transformation form of communication and collaboration. The method of this study adopts a structural equation model to test a mediating effect of communication and a moderating effect of change resistance level. This model confirms whether smart work investments provide a positive impact on communication and organizational productivity. In addition, I will classify a change resistance level of smart work by cluster analysis and then check a critical path difference of job productivity between each group. As a result, The organizational IT, institution and culture on the smart work investment appeared to important influencers in communication and also had a direct influence of individual performance. Also, The three independent variables of smart work investment have an indirect influence of individual and organizational performance through communication mediating variables. However, the organizational IT and institution as independent variables do not provide direct influence of organization performance. Nevertheless, two independent variables of organizational IT and institution have an indirect influence the organization performance through communication mediating variables. As a result of confirming a productivity of three groups on organization resistance, there was a difference the individual and organizational performance among groups. The low-level group of organizational resistance showed high coefficient value of performance compared to other groups. The group analysis implications, The smart work investment appeared significantly to revise the institution first, build culture secondly and advanced technology lastly. The theoretical implication from this study contributes an extension of social science theory through socio-technical systems, institution, culture, change resistance and job performance based on smart work. The practical implications explain the smart work success in step-by-step investment rather than radical investment as level management of change resistance. In future research, the smart work performance between private and public firms will analyze a difference of the organizational culture, institution, technology and performance.

• Radiation Oncology Journal
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• v.25 no.3
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• pp.177-184
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• 2007

Purpose: To evaluate the palliative effect of endobronchial brachytherapy (EBB) for patients with lung cancer that previously received external beam radiotherapy (EBRT). Materials and Methods: From July 1992 to May 2003, 29 patients with a recurrent or persistent lung cancer were treated with palliative EBB at our institute. EBB consisted of three fractions (once a week) of a dose of 5 Gy using the high dose-rate remote afterloader. Symptomatic improvement was assessed subjectively, and patients were divided into two groups according to whether symptoms were improved or not. Factors such as age, performance status, duration from EBRT to EBB and the location of the tumor were compared between the improved and unimproved groups of patients. Results: Overall symptomatic improvement was found in 27 out of 52 symptoms (52%). Improvement as to the type of symptoms was seen in 41 %, 50%, 82% and 33% of patients with cough, dyspnea, hemoptysis, and obstructive pneumonia respectively. The rate of improvement of hemoptysis was more than that of cough (p<0.05). The median time to symptom relapse was 5 months. The improved patient group (n=17, 59%) had a better performance status and longer duration from EBRT to EBB than the unimproved patient group (p<0.05). Lesions located in the distal trachea and/or main bronchus were found more frequently in the improved group of patients than in the unimproved group of patients, but the difference was not statistically significant (p=0.06). Fatal complications developed in two patients (7%), which were a hemoptysis and bronchopleural fistula respectively. Conclusion: Symptom improvement was found in 60% of patients after EBB and improvement was maintained for 5 months. Palliative EBB, even when EBRT was given previously, can be effective for a patient that has an endobronchial symptom, such as hemoptysis, and for a patient with good performance and a long duration from previous EBRT to EBB.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.135-140
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• 2014

Pre-storage ultra-violet (UV) light treatment on fresh produce is known to inactivate the contaminated microorganisms, activate the defense system, and delay ripening extending the shelf life. As UV light emitting diode (LED) becomes available at a relatively low price, continuous or intermittent UV treatment during chilled storage is possible in a container or package. This study attempted an in situ UV LED treatment on fresh produce stored under a refrigerated container in order to see its potential in the fresh produce storage and further optimize its application conditions. The effect of in-container UV LED irradiation on the quality preservation of shredded carrots was investigated in the air and modified atmosphere (MA) conditions. Two sets of experiment with Escherichia coli inoculation and with natural microbial flora in the air (two 30 minute on-off cycles of 1 $diode/dm^2$ per day at a location above 2 cm) showed a clear and significant effect of the UV LED irradiation on the suppression of microbial growth: 280 nm was the most effective by maintaining a lower microbial count by at least 0.5 log (CFU/g) throughout the 6 day storage period. The carotenoids content of shredded carrots subjected to UV LED treatment at 365 and 405 nm in the air was higher than that of the control shredded carrots. In MA condition of $O_2$ of 1.2~4.3% and $CO_2$ of 8.4~10.6% being indifferent with LED wavelengths, 280 nm UV LED irradiation was also effective in inhibiting the microbial growth. While there was no observed difference in the carotenoids content between untreated and UV LED-treated shredded carrots in MA, UV LED irradiation at 365 and 405 nm was slightly better in DPPH radical scavenging activity. The use of UV LED in storage container or package seems to give the benefits of preserving the microbial and nutritional qualities of minimally processed fruits and vegetables.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.1
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• pp.76-82
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• 2017

Purpose Whole body bone scan is one of the most frequently performed in nuclear medicine. Basically, both the anterior and posterior views are acquired simultaneously. Occasionally, it is difficult to distinguish the lesion by only the anterior view and the posterior view. In this case, accurate location of the lesion through SPECT / CT or additional static scan images are important. Therefore, in this study, various improvement activities have been carried out in order to enhance the work capacity of technologists. In this study, we investigate the effect of technologist training and standardized work process processes on bone scan error reduction. Materials and Methods Several systems have been introduced in sequence for the application of new processes. The first is the implementation of education and testing with physicians, the second is the classification of patients who are expected to undergo further scanning, introducing a pre-filtration system that allows technologists to check in advance, and finally, The communication system called NMQA is applied. From January, 2014 to December, 2016, we examined the whole body bone scan patients who visited the Department of Nuclear Medicine, Asan Medical Center, Seoul, Korea Results We investigated errors based on the Bone Scan NMQA sent from January 2014 to December 2016. The number of tests in which NMQA was transmitted over the entire bone scan during the survey period was calculated as a percentage. The annual output is 141 cases in 2014, 88 cases in 2015, and 86 cases in 2016. The rate of NMQA has decreased to 0.88% in 2014, 0.53% in 2015 and 0.45% in 2016. Conclusion The incidence of NMQA has decreased since 2014 when the new process was applied. However, we believe that it will be necessary to accumulate data continuously in the future because of insufficient data until statistically confirming its usefulness. This study confirmed the necessity of standardized work and education to improve the quality of Bone Scan image, and it is thought that update is needed for continuous research and interest in the future.

• Journal of the Korean earth science society
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• v.42 no.3
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• pp.264-277
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• 2021

This study analyzed the relationship between the total precipitable water vapor in the atmosphere and the moving speed of recent typhoons. This study used ground observation data of air temperature, precipitation, and wind speed from the Korea Meteorological Administration (KMA) as well as total rainfall data and Red-Green-Blue (RGB) composite images from the U.S. Meteorological and Satellite Research Institute and the KMA's Cheollian Satellite 2A (GEO-KOMPSAT-2A). Using the typhoon location and moving speed data provided by the KMA, we compared the moving speeds of typhoon Bavi, Maysak, and Haishen from 2020, typhoon Tapah from 2019, and typhoon Kong-rey from 2018 with the average typhoon speed by latitude. Tapah and Kong-rey moved at average speed with changing latitude, while Bavi and Maysak showed a significant decrease in moving speed between approximately 25°N and 30°N. This is because a water vapor band in the atmosphere in front of these two typhoons induced frontogenesis and prevented their movement. In other words, when the water vapor band generated by the low-level jet causes frontogenesis in front of the moving typhoon, the high pressure area located between the site of frontogenesis and the typhoon develops further, inducing as a blocking effect. Together with the tropical night phenomenon, this slows the typhoon. Bavi and Maysak were accompanied by copious atmospheric water vapor; consequently, a water vapor band along the low-level jet induced frontogenesis. Then, the downdraft of the high pressure between the frontogenesis and the typhoon caused the tropical night phenomenon. Finally, strong winds and heavy rains occurred in succession once the typhoon landed.