• Journal of Aquaculture
• /
• v.22 no.1
• /
• pp.16-22
• /
• 2009

Life history of Korean crayfishes Cambaroides similis (Koelbel) was studied 8 month from March to October, 2006 from the Gwanak mountain, Seoul, South Korea. By capture and recapture method, 551 crayfishes were collected analyzed during the experimental period. Based on the distribution pattern of body lengths, the local population putatively divided into four age groups. The sex ratio of male and female was almost equal. However, their growth rates varied by water temperature. Early juveniles seen during June became adult during August. The study findings suggest that late autumn is mating season.

• The Journal of the Korean dental association
• /
• v.58 no.8
• /
• pp.496-504
• /
• 2020

The osseointegrated implants react biomechanically in a different pattern to occlusal force, due to lack of the periodontal ligament unlike the natural teeth. The implants show markedly less movement and limited tactile sensitivity compared with the natural teeth. The implant occlusion concept aims to avoid overloading on the implants and to direct occlusal loads along the longitudinal axis of the implants, in order to compensate for the different biomechanics of the implants. Although many guidelines and theories on implant occlusion have been proposed, few have provided strong supportive evidence. Moreover, the outcome of treatment often quite successful in spite of different concepts of occlusion and there is an increasing tendency to doubt about the strict theoretical implant-specific occlusion concept. The purpose of this article is to review the previous reports about the concept of implant occlusion and discuss clinical occlusal considerations in implant rehabilitations.

• The Korean Journal of Emergency Medical Services
• /
• v.19 no.2
• /
• pp.99-115
• /
• 2015

Purpose: This study aimed to provide basic data for clinical training program development by analyzing the operating conditions and satisfaction in a clinical training program for 119 emergency medical technicians (EMTs) in South Korea. Methods: Data from 84 EMTs were collected on June 19, 2014. We administered a 64-item questionnaire about operating conditions and satisfaction in the clinical training program, and analyzed data (SPSS v 21.0). Results: The degree of performance in the field, importance of the item in the field, and level of difficulty were 3.36, 4.23, and 3.21, respectively. In the number of times that an item was directly performed according to the subjects' general characteristics a statistically difference in sex (p = .000), duty (p =.021), and total working time of trainees (p = .002). The subjects' total satisfaction score was 3.77. The difference in satisfaction according to the subjects' characteristics was a statistically significant in terms of sex (p = .016) and clinical training area (p = .005). Conclusion: A more efficient training system for hospital clinical training courses should be developed. The operation condition analyzed in this research may contribute to the improvement of the performance of EMTs.

• Journal of The Korean Astronomical Society
• /
• v.55 no.6
• /
• pp.207-213
• /
• 2022

The Seoul Radio Astronomy Observatory (SRAO) operates a 6.1-meter radio telescope on the Gwanak campus of Seoul National University. We present the efforts to reform SRAO to a Very Long Baseline Interferometry (VLBI) station, motivated by recent achievements by millimeter interferometer networks such as Event Horizon Telescope, East Asia VLBI Network, and Korean VLBI Network (KVN). For this goal, we installed a receiver that had been used in the Combined Array for Research in Millimeter-wave Astronomy and a digital backend, including an H-maser clock. The existing hardware and software were also revised, which had been dedicated only to single-dish operations. After several years of preparations and test observations in 1 and 3-millimeter bands, a fringe was successfully detected toward 3C 84 in 86 GHz in June 2022 for a baseline between SRAO and KVN Ulsan station separated by 300 km. Thanks to the dual frequency operation of the receiver, the VLBI observations will soon be extended to the 1 mm band and verify the frequency phase referencing technique between 1 and 3-millimeter bands.

• Korean Institute of Interior Design Journal
• /
• v.23 no.6
• /
• pp.160-168
• /
• 2014

Five strongest crimes against women has rapidly increased recently, and women' anxiety is also increasing. Especially, women who reside alone in houses show significantly high anxiety. Such social change is increasing necessity of applying CPTED to housing environment of a single woman household. However, there have been less than enough number of researches on application on CPTED to housing environment of single woman household. So, this study would like to suggest housing environment of single woman household through CPTED guideline. With respect to research method, this study surveyed single woman households in their twenties and thirties who reside at single houses in Gwanak Gu, Gangnam Gu, Songpa Gu, and Mapo Gu in Seoul about necessity of CPTED guideline. Based on the survey results, this study conducted frequency analysis and descriptive statistics; and conducted independent sample t-test, one-way ANOVA, and Scheffe's posteriori test, according to demographic characteristics. As a result, differences in the contents of CPTED guideline by the demographic characteristics turned out to be small, generally. Thus, I concluded that suggestion for housing environment according to characteristics is not necessary. Instead, I would suggest contents of CPTED guideline that gained more than 4 points for housing environment. Research results of this study are as follow. First, 'Securing view of inside and outside of the house and controlling access' should be applied to housing environment of single woman households in their twenties and thirties residing in single houses in Seoul. Second, 'Securing view of an alley and improving walking space' should be applied. Third, 'installing CCTV and emergency bell' should be applied. Fourth, 'reinforcing territoriality of space' should be applied.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.12 no.5
• /
• pp.101-109
• /
• 2009

There are increasing needs about creation and sustainable management of urban forest for environmental conservation and recreational service for citizen. However, it is difficult for local governments to create or manage urban forest in recreational or conservational way. The purpose of this study is to classify the urban forest types by considering its geographical feature, biological and sociological characteristics in order to suggest a guide to local governments about effective creation or management of urban forest. In this study, we extracted common characteristics of the selected five indicators. Factors about urban forest are divided into two groups. Factors were named according to the variables as 'Urban Forest Naturalness', and 'High Accessibility and Disturbed by Human.' In addition, we classified urban forests into four types in this study. The type I of urban forest is a large forest and has high naturalness such as Mt. Bukhan and Mt. Gwanak. The type II is fragmented to large forests by developmental projects. The type III is flat and has high accessibility such as forest behind Seonjeongneung. The type IV is located near residential area such as Mt. Ansan, Mt. Inwang and Mt. Bonghwa. It is possible to set up recreational area for citizens and ecological networks for species by the research of the urban forest type. The results of the study, classification of urban forest types and its application, contribute to provide a guide for local governments to create or manage urban forests effectively.

• Korean Journal of Childcare and Education
• /
• v.6 no.2
• /
• pp.135-154
• /
• 2010

This study was to explore the cognition of mothers and directors about the quality of childcare centers and analyze the differences of cognition of two groups. The subjects were 166 mothers and 178 directors in Gwanak-gu, Seocho-gu, Dongjak-gu in Seoul and Suweon-city, Anyang-city in Gyeonggi-do. The instrument of this study was the questionnaire on the quality of childcare center developed by researcher. The collected data were analyzed using t-test in SPSS 12.0 program. The major findings of this study were as follows: First, mothers evaluated that process area was the most important area, followed by service and structure area. Second, directors evaluated that process area was the most important area, followed by structure and service area. Third, directors evaluated overall quality of childcare center higher than mothers.

• Journal of Korean Society for Atmospheric Environment
• /
• v.20 no.5
• /
• pp.697-711
• /
• 2004

Severe haze, mist, and fog phenomena occurred in the central part of Korea during 15~25 May 2003 resulted in poor visibility and air quality. When these phenomena occurred, Korean peninsula was under the effects of anticyclone. The atmosphere was stable, and wind speed was so weak. Under this meteorological conditions, air quality was worse and worse. The characteristics of aerosol in Seoul, Incheon, and Gosan (Jeju) during this period are investigated from the $PM_{10}$. TSP concentrations and aerosol number concentrations. Concentrations of $PM_{10}$ and TSP measured at KMA increased upto 176 and 230 J.${\mu}g/m^3$ on 22 May 2003, respectively. Aerosol number concentrations of size range from 0.82 to 6.06 ${\mu}m$ increased in Seoul on 17, 19, and 21~24 May 2003, and the concentrations of $NO_2$ and $SO_2$had maximum value of 0.165 ppm at Gwanak Mt. and 0.036 ppm at Guro-dong on 23 May 2003, respectively. Result from analysis on heavy metal elements showed high concentrations of Zn, Pb, Cr, Ni, Cu, and Cd during 20~24 May 2003. This event is examined by comprehensive analyses of synoptic weather conditions, satellite images, concentrations of suspended particles and air pollutants, and heavy metal elements.

• The korean journal of orthodontics
• /
• v.46 no.1
• /
• pp.3-12
• /
• 2016

Objective: The purpose of this study was to compare the precision of three-dimensional (3D) images acquired using iTero$^{(R)}$(Align Technology Inc., San Jose, CA, USA) and Trios$^{(R)}$(3Shape Dental Systems, Copenhagen, Denmark) digital intraoral scanners, and to evaluate the effects of the severity of tooth irregularities and scanning sequence on precision. Methods: Dental arch models were fabricated with differing degrees of tooth irregularity and divided into 2 groups based on scanning sequence. To assess their precision, images were superimposed and an optimized superimposition algorithm was employed to measure any 3D deviation. The t-test, paired t-test, and one-way ANOVA were performed (p < 0.05) for statistical analysis. Results: The iTero$^{(R)}$ and Trios$^{(R)}$ systems showed no statistically significant difference in precision among models with differing degrees of tooth irregularity. However, there were statistically significant differences in the precision of the 2 scanners when the starting points of scanning were different. The iTero$^{(R)}$ scanner (mean deviation, $29.84{\pm}12.08{\mu}m$) proved to be less precise than the Trios$^{(R)}$ scanner ($22.17{\pm}4.47{\mu}m$). Conclusions: The precision of 3D images differed according to the degree of tooth irregularity, scanning sequence, and scanner type. However, from a clinical standpoint, both scanners were highly accurate regardless of the degree of tooth irregularity.

• Journal of Korean Society for Atmospheric Environment
• /
• v.31 no.1
• /
• pp.83-91
• /
• 2015

Biomass burning is known to be one of the main sectors emitting greenhouse gases as well as air pollutants. Unfortunately, the inventory of biomass burning sector has not been established well. We estimated greenhouse gas (GHG) and air pollution (AP) integrated emissions from biomass burning sector in Seoul during year 2010. The data of GHG and AP emissions from biomass burning, classified into open burning, residential fireplace and wood stove, meat cooking, fires, and cremation, were obtained from Statistics Korea and Seoul City. Estimation methodologies and emission factors were gathered from reports and published literatures. Estimated GHG and AP integrated emissions during year 2010 were $3,867tonCO_{2eq}$, and 2,320 tonAP, respectively. Major sources of GHG were forest fires ($1,533tonCO_{2eq}$) and waste open burning ($1,466tonCO_{2eq}$), while those of AP were meat cooking (1,240 tonAP) and fire incidence (907 tonAP). Total emissions by administrative district in Seoul, representing similar patterns in both GHG and AP, indicated that Seocho-gu and Gangseo-gu were the largest emitters whereas Jung-gu was the smallest emitter, ranged in $2{\sim}165tonCO_{2eq}$ and 0.1~8.31 tonAP. GHG emissions per $km^2$ showed different results from total emissions in that Gwanak-gu, Jungnang-gu, Gangdong-gu and Seodaemun-gu were the largest emitters, while Seocho-gu and Gangseo-gu were near-averaged emission districts, ranged in $0.2{\sim}21tonCO_{2eq}/km^2$. However, AP emissions per $km^2$ revealed relatively minor differences among districts, ranged in $2.3{\sim}6.1tonAP/km^2$.