• Korean Journal of Radiology
• /
• v.19 no.6
• /
• pp.1031-1041
• /
• 2018

Objective: To compare image quality and radiation dose of high-pitch dual-source spiral cardiothoracic computed tomography (CT) between non-electrocardiography (ECG)-synchronized and prospectively ECG-triggered data acquisitions in young children with congenital heart disease. Materials and Methods: Eighty-six children (${\leq}3$ years) with congenital heart disease who underwent high-pitch dual-source spiral cardiothoracic CT were included in this retrospective study. They were divided into two groups (n = 43 for each; group 1 with non-ECG-synchronization and group 2 with prospective ECG triggering). Patient-related parameters, radiation dose, and image quality were compared between the two groups. Results: There were no significant differences in patient-related parameters including age, cross-sectional area, body density, and water-equivalent area between the two groups (p > 0.05). Regarding radiation dose parameters, only volume CT dose index values were significantly different between group 1 ($1.13{\pm}0.09mGy$) and group 2 ($1.07{\pm}0.12mGy$, p < 0.02). Among image quality parameters, significantly higher image noise ($3.8{\pm}0.7$ Hounsfield units [HU] vs. $3.3{\pm}0.6HU$, p < 0.001), significantly lower signal-to-noise ratio ($105.0{\pm}28.9$ vs. $134.1{\pm}44.4$, p = 0.001) and contrast-to-noise ratio ($84.5{\pm}27.2$ vs. $110.1{\pm}43.2$, p = 0.002), and significantly less diaphragm motion artifacts ($3.8{\pm}0.5$ vs. $3.7{\pm}0.4$, p < 0.04) were found in group 1 compared with group 2. Image quality grades of cardiac structures, coronary arteries, ascending aorta, pulmonary trunk, lung markings, and chest wall showed no significant difference between groups (p > 0.05). Conclusion: In high-pitch dual-source spiral pediatric cardiothoracic CT, additional ECG triggering does not substantially reduce motion artifacts in young children with congenital heart disease.

• The Journal of Korean Society for Radiation Therapy
• /
• v.34
• /
• pp.61-72
• /
• 2022

Purpose: Conventional CBCT(Cone-beam Computed-tomography) caused an error in the target volume due to organ movement in the area affected by respiratory movement. The purpose of this paper is to evaluate the usefulness of accuracy and time spent using the Gated CBCT function, which reduces errors when performing RGRT(respiratory gated radiation therapy), and to examine the appropriateness of phase. Materials and methods: To evaluate the usefulness of Gated CBCT, the QUASAR^TM respiratory motion phantom was used in the Truebeam STx^TM. Using lead marker inserts, Gated CBCT was scaned 5 times for every 20~80% phase, 30~70% phase, and 40~60% phase to measure the blurring length of the lead marker, and the distance the lead marker moves from the top phase to the end of the phase was measured 5 times. Using Cedar Solid Tumor Inserts, 4DCT was scanned for every phase, 20-80%, 30-70%, and 40-60%, and the target volume was contoured and the length was measured five times in the axial direction (S-I direction). Result: In Gated CBCT scaned using lead marker inserts, the axial moving distance of the lead marker on average was measured to be 4.46cm in the full phase, 3.11cm in the 20-80% phase, 1.94cm in the 30-70% phase, 0.90cm in the 40-60% phase. In Fluoroscopy, the axial moving distance of the lead marker on average was 4.38cm and the distance on average from the top phase to the beam off phase was 3.342cm in the 20-80% phase, 3.342cm in the 30-70% phase, and 0.84cm in the 40-60% phase. Comparing the results, the difference in the full phase was 0.08cm, the 20~80% phase was 0.23cm, the 30~70% phase was 0.10cm, and the 40~60% phase was 0.07cm. The axial lengths of ITV(Internal Target Volume) and PTV(Planning Target Volume) contoured by 4DCT taken using cedar solid tumor inserts were measured to be 6.40cm and 7.40cm in the full phase, 4.96cm and 5.96cm in the 20~80% phase, 4.42cm and 5.42cm in the 30~70% phase, and 2.95cm and 3.95cm in the 40~60% phase. In the Gated CBCT, the axial lengths on average was measured to be 6.35 cm in the full phase, 5.25 cm in the 20-80% phase, 4.04 cm in the 30-70% phase, and 3.08 cm in the 40-60% phase. Comparing the results, it was confirmed that the error was within ±8.5% of ITV Conclusion: Conventional CBCT had a problem that errors occurred due to organ movement in areas affected by respiratory movement, but through this study, obtained an image similar to the target volume of the setting phase using Gated CBCT and verified its usefulness. However, as the setting phase decreases, the scan time was increases. Therefore, considering the scan time and the error in setting phase, It is recommended to apply it to patients with respiratory coordinated stereotactic radiation therapy using a wide phase of 30-70% or more.

• Weed & Turfgrass Science
• /
• v.7 no.3
• /
• pp.201-208
• /
• 2018

This study was conducted to investigate the occurrence and distribution of herbicide resistant weeds at rice fields in Chungnam province of Korea in 2017. Herbicide-resistant weeds occurred in 64,782 ha, which comprise 47.0% of the total paddy field area of Chungnam province. The infested area of herbicide resistant weeds was estimated in Seosan-si (11.9%), Nonsan-si (11.1%), Dangjin-si (10.9%), Boryeong-si (9.2%) and Asan-si (7.8%). The most dominant herbicide resistant weeds in rice fields were Monochoria vaginalis, followed by Lindernia dubia, Schoenoplectus juncoides, Echinochloa oryzicola, Cyperus difformis and Sagittaria trifolia. Herbicide resistant M. vaginalis, L. dubia, and S. juncoides occurred throughout Chungnam province, and herbicide resistant S. trifolia was only found in Dangjin-si. Compared with the 2011 survey, the infested area of herbicide-resistant weeds decreased, but the incidence rates were similar. The herbicide rotation with different modes of actions across growing seasons is recommended to control herbicide-resistant weeds in the infested fields. It is necessary to monitor herbicide resistance regularly and conduct integrated herbicide resistance management in this area.

• Journal of the Korean Society of Industry Convergence
• /
• v.12 no.2
• /
• pp.79-83
• /
• 2009

In this study, actual state of operation of rotary tillage was surveyed in the central part of Korea which includes 29 rural community around Asan city, Choongnam principal. 29 heads of the village and 44 farmers were surveyed at the field with a questionnaire on the operation of rotary tillage with farm tractors. Power requirement of rotary tillage operation was measured at the field of each farmers during rotary tilling operation in the central part of Korea. Summaries of this study are summarized as follows. 1) Operations of tillage and land preparation were found to be carried out with farm tractors by 98 percents which are results of the survey on 29 heads of the village and 44 farmers. 2) More than half of the farms had tractors with horsepower more than 38 kW which states that most tractors were supplied in middle and large size. 3) The case of applying secondary tillage after the first primary tillage were 79 percent among the most of operations of tillage and field preparation. Rotary tillage were carried out on the most of wet paddy fields and only 14 percent of dry fields were cultivated with rotary tillage. 4) 63.6 percent of farm tractors were surveyed to meet the recommended field capacity on tillage operation by the government which were ranged from 15.1 to 34.9 ha. And the field capacity of these farm tractors were greater than that of annual total area of operation field, 13.2ha (data from Information of agricultural machinery, National agricultural products quality service, Korea), which states the utilization of agricultural machinery was high in the area surveyed. 5) 46 percent of farmers changed the blade of rotary implement when they used it over the field capacity of rotary blade of 33 ha which is the area of field for rotary operation per a blade change. 55 percent of farmers changed the rotary blade more than once per two years. 6) The required power for rotary operation of each farm tractors were measured as 17.206 kW at untilled paddy field and 34.989 kW at untilled dry field on the average, respectively. The required power for rotary operation was measured as 28.248 kW on the average at the paddy field which had been plowed once and 28.015 at the paddy field that had rotary tillage operation. Untilled dry field showed the highest value of the required power for rotary operation.

• Korean Journal of Ichthyology
• /
• v.5 no.2
• /
• pp.184-193
• /
• 1993

The distribution, and length and age compositions of Johnius belengeri were studied using samples collected by an otter trawl from the five different coastal waters of Korea ; Asan Bay, Cheonsu Bay, waters off Yeongkwang and Samchonpo, and Yeongil Bay. This fish showed a high density of 1,147 individuals/$10,000m^2$ and predominated in abundance of the demersal fish in the coastal water off Yeongkwang. The mean density was 94 individuals/$10,000m^2$ in Cheonsu Bay and 8-24 individuals/$10,000m^2$ in Asan Bay and in the water off Samchonpo. Few fish were collected from Yeongil Bay. J. belengeri occurred from spring to autumn in the study area and showed a relatively high density in spring or in summer. The fish collected in spring and in summer composed of adults of age group I, II and III. Some juveniles began to occurred in the waters off Yeongkwang and Samchonpo from summer. The fish collected in autumn consisted mainly of the fish of age group 0. It implies that the adults after spawning moved out from the embayments for feeding. but the young fish stayed and grew in the embayments until late autumn when they migrated to the offshore water for wintering.

• Environmental Analysis Health and Toxicology
• /
• v.30
• /
• pp.2.1-2.9
• /
• 2015

Objectives This study aimed to evaluate the association between presence of depression symptoms and the exposure level to insecticides among aged population in rural area, determined via measured levels of urinary 3-phenoxybenzoic acid (3-PBA), after controlling for socioeconomic confounding factors. Methods Using a cross-sectional study design, we randomly recruited participants for our study (161 male and 239 female) from rural areas of Asan, Chungnam, Korea. Environmental risk factor exposure was assessed using a questionnaire, and gas chromatography-mass spectrometry was used to analyze urinary 3-PBA levels. We used a logistic regression analysis to assess the association of urinary 3-PBA levels with the presence of self-reported depression symptoms. Results After controlling for creatinine levels, the median (interquartile range) concentration of 3-PBA was approximately 1.5 times (p<0.05) higher among female (1.54 [0.90 to 2.35]) ${\mu}g/g$) than among male (1.06 [0.64 to 1.81] ${\mu}g/g$). Our study found that among female participants, the unit increase in 3-PBA levels exhibited a likely positive association (odds ratio, 1.12; 95% confidence interval, 1.00 to 1.25) with an increased risk of presence of self-reported depression symptoms, after adjusting for socioeconomic insurance type, daily physical condition, marital status, smoking status, and age. Conclusions Given our finding of a potential association between the presence of self-reported depression symptoms and 3-PBA levels, precautions should be considered to minimize exposure to insecticides and thus protect the health of aged residents in rural areas.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.30 no.2
• /
• pp.55-66
• /
• 1988

This study was conducted to investigate the various engineering properties and correlationshops among the soil constants of alluvial clayey deposits distributed in the bay of Asan and their results are summarized as follows : 1. Grain size distribution of soil was consisted of 12 % of clay, 46-73 % of silt, 2-23 % of sand, and as for the consistency characteristics, 26-36 % of liquid limit, 18-21 % of plastic limit and 6-16 % of plastic index, and so the soil belonging to as a lower plastic nonorganic clay, it's specific gravity was 2,66-2.70, and the location on the plastic chart was approximately above the A-line. Z The natural moisture content and unit weight were 30-43 % and 1.76-1.87 g I cm$_3$, respectively, and according to increment of natural moisture content, the unit weight was decreased, and the initial void ratio and degree of saturation were shown of 0,87-1119 and 92- 100 %, most of saturated. 3. Cone resistance value which was shown 2.4 - 6.5 kg / $cm^2$ was a little lower and it was increased with the depth of layer and shown the formular $q_c=0.7_z+1.32$. 4. Unconfined compression strength was about 0.18-0.43kg /$cm^2$, cu, 0.1-0.22kg / $\psi$, $2-6^{\circ}$ under uu-test condition of triaxial, and CCU, 0.08-0.3 kg/cm , $\psi$, $12-18^{\circ}$ under the condition of cu-test. 5. Pre-consolidation load of characteristics of consolidation was 0.4-0.8 kg / $cm^2$, compression index, about 0.17-0.33. 6. Liquid limit and plastic index were incresased with the increment of clay content but most of alluvial clay was appeared as a normal through non-activity clay soil shown more natural moisture content than liquid limit, and their relationship as follows : LL=0.38( cy+54.8), PI=0.836(LL -17.8), PI =0.468(LL -0.48) 7. The initial void ratio presented correlationship of positive among clay content, natural moisture content and liquid limit, and that of reverse with unit weight, and their results as follws : $e_o=0.024(w_n+0.2)$, $e_o=e_o=0.0003c_y+0.0005 LL+0.0151 W_n+\frac{3.58}{r-t}-1.52$ 8. It was shown that the compression index has correlationship of postive among the clay content, liquid limit, plastic index, natural moisture content and initial void ratio, and their relationships as follows ; $c_c=0.44(e_o-0.47)$, $c_c=0.001$

• Anxiety and mood
• /
• v.5 no.1
• /
• pp.29-35
• /
• 2009

Background : In spite of the worldwide relevance of obsessive-compulsive disorder Ed-highlight : Unclear. Perhaps consider changing word choice. (OCD), there are considerable differences in prevalence, sex ratio, comorbidity patterns, and sociodemographic correlates. Data on subclinical OCD have been sparse to date. Methods : Data stemmed from the Korea Epidemiologic Catchment Area (KECA) study which had been carried out from April to December 2001. Korean versions of DSM-IV adapted Composite International Diagnostic Interview were administered to a representative sample of 6275 persons aged 18-64 living in the community. DSM-IV based criteria for subclinical OCD were applied. Results : The lifetime prevalence rates for OCD and subclinical OCD were 0.8% and 6.6%, respectively. In both OCD and subclinical OCD, the rates for males and females were not statistically different. OCD was demonstrated to be associated with depressive disorder, bipolar disorder, social phobia, generalized anxiety disorder, and alcohol and nicotine dependence. Additionally, subclinical OCD was associated with posttraumatic stress and somatoform disorders. Comorbidity rates in subclinical OCD were lower than those in OCD. Conclusions : The lifetime prevalence rate for OCD was less than 1% in the Korean general population. Age distribution and comorbidity patterns suggest that subclinical OCD represents a broad and heterogeneous syndrome and not simply a milder form of OCD.

• Journal of architectural history
• /
• v.16 no.3
• /
• pp.75-94
• /
• 2007

There were many researches on marine transportation and granaries, most of which focused on the historical establishment and organization of the marine transportation. However, a few researches were conducted on the architectural aspects. Hence the purposes of this study are to investigate the following matters: first, documents and relics concerning the tribute granary castle at Cape Gongse in Asan, a typical granary during the Joseon Dynasty, were investigated to academically understand the castle's establishment and historical background; second, the dispositional characteristics of the granary and the castle, including its adjacent facilities, were investigated to review its archaeological value; finally, basic materials were provided for systematical preservation and management these relics. As for the research method, the author referred to and analyzed sundry records and old maps, and ascertained in detail historical evidence through residential testimonies and the on-the-spot surveys. In addition, the author investigated the dispositional characteristics of the tribute granary castle at Cape Gongse by analyzing its exact size and shape, based on the old documents and an actual survey of the castle remains. The characteristics of the tribute granary castle at Cape Gongse may be summarized as follows. First, tribute granary at cape Gongse is a only tribute granary which has a granary and castle. second, the tribute granary castle at Cape Gongse has a curvilinear shape, like a gourd dipper; a large circle surrounding the village and a small circle surrounding the area of Mt. Shinpoong both meet up with it. Third, the construction type of the tribute granary castle at Cape Gongse is in a style similar to a town castle or a battle camp castle located in the coastal regions. As for its locational conditions, however, the east gate, presumably an incoming and outgoing route to the granary for vessels, was a feature unique to the marine granary castle. Fourth, the tribute granary at Cape Gongse had a granary of eighty kan in 1523 and, in addition, there were also Bongsang-cheong, Sa-chang, Joseon-sobakcheo, Chimhae-dang, and more, not to mention many privates houses in the castle. The granary is located in the center of the tribute granary castle, where Gongse Nonghyub is currently located. The location of the government offices seemed to be on the northern ridge. Fifth, the tribute granary castle at Cape Gongse is a valuable relic that offers insight into marine transportation, tribute granaries, and tribute granary castles during the Joseon Dynasty. It has special archaeological value because it was one of only a few tribute granary castles that served to protect the tribute granaries.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.20 no.2
• /
• pp.68-75
• /
• 2009

Objectives: This study was conducted in order to develop and obtain the nonnative data of the computerized Comprehensive Attention Test(CAT) in Korean children and adolescents. It also aimed to evaluate the reliability and validity of the CAT. Methods: We developed the computerized CAT which includes the selective attention task, the sustained attention to response task, the flanker task, the divided attention task, and the spatial working memory task. We investigated the test-retest reliability and the construction validity of this computerized version by using the data from 21 children, and gathered the nonnative data of 9l2 subjects, aged 4 to 15 years, dwelling in the Metropolitan Seoul area in 2008. Results: No statistical differences between means of the tests and retests of the CAT were observed. The mean of the correlation coefficient of the test-retest scores was 0.715. The results from the factor analyses explained 51.7% of the cumulative variance. In addition, the nonnative data for all of the CAT subtests were obtained. Conclusion: The computerized CAT can be used as a reliable and valid tool in both clinical and research settings for Korean children and adolescents with or without neuropsychiatric conditions such as attention deficit.