• Nuclear Medicine and Molecular Imaging
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• v.40 no.5
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• pp.257-262
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• 2006

Purpose: The standard protocol using large volume of oral contrast media may cause gastrointestinal discomfort and contrast-related artifacts in PET/CT. The aim of this study was to evaluate the usefulness of low dose oral contrast in $^{18}F-FDG$ PET/CT. Materials and Methods: We retrospectively reviewed the whole-body PET/CT images in a total of 435 patients. About 200 ml of oval contrast agent (barium sulfate) was administered immediately before injection of $^{18}F-FDG$. The FDG uptake of intestines was analyzed by visual and semi- quantitative method on transaxial, coronal and saggital planes. Results: Seventy (16%, 113 sites) of 435 images showed high FDG uptake (peak SUV > 4); 50 (74%, 84 sites) with diffuse and 20 (15%, 29 sites) with focal uptake. The most commonly delivered site of oral contrast media was small bowel (n=27, 39%). On PET/CT images, FDG uptake coexisted with oral contrast media in 26 patients (54%, 38 sites) with diffuse pattern and 9 (45%, 9 sites) with focal pattern, and by sites, those were 38 (45%) and 9 (31%), respectively. In small bowel regions, the proportion of coexistence reached as high as 61% (29/47 sites). A visual analysis of available non-attenuation corrected PET images of 27 matched regions revealed no contrast-related artifact. Conclusion: We concluded that the application of low dose contrast media could be helpful in the evaluation of abdominal uptake in the FDG PET/CT image.

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.693-702
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• 2015

In order to identify the species and to reveal the phylogenetic relationship of rook populations found in Jeju-do Province in winter seasons, we determined the sequences of mitochondrial cytochrome c oxidase I (COI) gene and analyzed the genetic structure of maternal lineages and phylogenetic relationship. The rook DNAs were isolated from the post-mortem specimens and plumages collected from agricultural farms in Jeju-do Province including U-do Island. The obtained COI sequences (n=41) showed over 97.0% identities with those previously reported from Corvus frugeligus. Three COI haplotypes (J01-J03) were detected from COI sequences of the rooks obtained in Jeju-do Province but those did not show the site-specific patterns, showing that they might be derived from a common maternal origin. Eight maternal haplotypes were detected from all COI sequences obtained. Among those three haplotypes contained the COI sequences from Northeast Asia including eastern Russia, Mongolia and South Korea. On the other hand, the other five haplotypes contained the COI sequences reported from Central Asia, Middle East, western Russia and European countries. The COI sequences from Jeju-do Province were located on three haplotypes (CF01-CF03) belonging to Northeast Asian rook lineages. The NJ tree showed the distinct branch patterns suggesting two different maternal lineages of C. frugilegus, which proposed as two parapatric subspecies, C. f. frugilegus (Western) and C. f. pastinator (Eastern). These findings using DNA barcoding approaches will be contributed to provide the information about avian fauna for understanding the genetic structure of maternal lineage, phylogenetic relationship and their molecular ecology.

• Radiation Oncology Journal
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• v.15 no.3
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• pp.233-241
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• 1997

Purpose : This study was done to evaluate the survival rate and Prognostic factors of patients with inoperable non-small cell lung cancer(NSCLC) treated with radiation therapy. Materials and Methods A retrospective analysis was undertaken of 62 Patients who had inoperable NSCLC treated with radiation therapy from January 1991 through December 1993. According to AJCC slaging, stage IIIA was 14 patients and stage IIIB was 48 patients. Forty Gy to 70.2Gy to the primary tumor site was delivered with daily fractions of 1.8Gy or 2Gy, 5days per week. Thirty-seven patients received neoadjuvant chemotherapy. Results : Complete, partial and no response to radiation therapy were 3 patients, 34 Patients and 25 patients, respectively The median survival period of all patients was 11 month. One rear survival rate, 2 year survival rateand 5 rear survival rate for all patients were 45.0%, 14.3%, and 6.0% respectively The median survival period was 6.5 months in stage IIIA and 13 months in stage IIIB. One year survival rates were 28.6% in stage IIIA and 50.3% in stage IIIB In univariaite analysis, prognostic factors affecting survival were T-s1aging, AJCC staging, and response after radiation therapy (P<0.05) . Pretreatment peformance status affected survival but was not statistically significant (0.050.1). In multivariate analysis, Pathology and response to radiation therapy are independently significant prognostic factor. T stage was marginally significant (P=0.0809). During follow-up duration, distant metastasis developed in 20 patients-bone metastasis in 10 patients, brain metastasis in 3 patients, liver mentastasis in 3 patients, contralateral lung metastasis in 1 patients and multiple metastases in 3 patients. Conclusion :　Conventional radiotherapy alone or combined chemoradiotherapy are unlikely to achieve long term survival in patients with NSCLC.　Surgery after concurrent chemoradiotherapy is Ivied to improve the local　control in our hospital

• Journal of Science and Technology Studies
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• v.18 no.2
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• pp.135-179
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• 2018

How do robots interact with the elderly? In this paper, we analyze the contexts of interaction between robots and the elderly and the role of mediators in initiating, facilitating, and maintaining the interaction. We do not attempt to evaluate the robot's performance or measure the impact of robots on the elderly. Instead, we focus on the circumstances and contexts within which a robot is situated as it interacts with the elderly. Our premise is that the success of human-robot interaction does not depend solely on the robot's technical capability, but also on the pre-arranged settings and local contingencies at the site of interaction. We select three television shows that feature robots for the elderly and one "dementia-prevention" robot in a regional healthcare center as our sites for observing robot-elderly interaction: "Grandma's Robot"(tvN), "Co-existence Experiment''(JTBC), "Future Diary"(MBC), and the Silbot class in Suwon. By analyzing verbal and non-verbal interactions between the elderly and the robots in these programs, we point out that in most cases the robots and the elderly do not meet one-to-one; the interaction is usually mediated by an actor who is not an old person. These mediators are not temporary or secondary components in the robot-elderly interaction; they play a key role in the relationship by arranging the first meeting, triggering initial interactions, and carefully observing unfolding interactions. At critical moments, the mediators prevent the interaction from falling apart by intervening verbally or physically. Based on our observation of the robot-elderly interaction, we argue that we can better understand and evaluate the human-robot interaction in general by paying attention to the existence and role of the mediators. We suggest that researchers in human-robot interaction should expand their analytical focus from one-to-one interactions between humans and robots to human-robot-human interactions in diverse real-world situations.

• Journal of the Korea Concrete Institute
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• v.25 no.5
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• pp.485-496
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• 2013

In recent years, frequent terror or military attacks by explosion or impact accidents have occurred. Examplary case of these attacks were World Trade Center collapse and US Department of Defense Pentagon attack on Sept. 11 of 2001. These attacks of the civil infrastructure have induced numerous casualties and property damage, which raised public concerns and anxiety of potential terrorist attacks. However, a existing design procedure for civil infrastructures do not consider a protective design for extreme loading scenario. Also, the extreme loading researches of prestressed concrete (PSC) member, which widely used for nuclear containment vessel, gas tank, bridges, and tunnel, are insufficient due to experimental limitations of loading characteristics. To protect concrete structures against extreme loading such as explosion and impact with high strain rate, understanding of the effect, characteristic, and propagation mechanism of extreme loadings on structures is needed. Therefore, in this paper, to evaluate the impact resistance capacity and its protective performance of bi-directional unbonded prestressed concrete member, impact tests were carried out on $1400mm{\times}1000mm{\times}300mm$ for reinforced concrete (RC), prestressed concrete without rebar (PS), prestressed concrete with rebar (PSR, general PSC) specimens. According to test site conditions, impact tests were performed with 14 kN impactor with drop height of 10 m, 5 m, 4 m for preliminary tests and 3.5 m for main tests. Also, in this study, the procedure, layout, and measurement system of impact tests were established. The impact resistance capacity was measured using crack patterns, damage rates, measuring value such as displacement, acceleration, and residual structural strength. The results can be used as basic research references for related research areas, which include protective design and impact numerical simulation under impact loading.

• Journal of Environmental Policy
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• v.4 no.2
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• pp.31-55
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• 2005

Dangsan forests and Rural Community Forests(RCF) have been historical assets for the rural communities of more than 40,000 in Korea and they have provided an identity through the cultural heritage. The Dangsan forests and the RCF are parts of a unique cultural landscape in the rural areas as components of stream landscape. In many cases, the Dangsan forests and the RCF are located close to stream corridors. The objective of this study was to understand the function of the Dangsan forests and the RCF on stream water quality and to evaluate its ecological landscape values. Through the consideration of international concensus and domestic government policy for close-to-nature stream, we could find out that Dangsan forests and RCF's have close relationship with the close-to-nature streams. The water quality of the streams close to the Dangsan forests and the RCF are maintained with local culture. It is also compared to the streams located where Dangsan forests and the RCF are absent. Eight study sites were selected. Water samples were collected at three different locations at each study site. Water samples were analyzed for temperature, pH, total P, total N, dissolved oxygen, EC, BOD, COD and SS. Aquatic invertebrates were observed as water quality indicator species. The results showed that the number of aquatic invertebrate species, GPI, DO, EC, BOD, and SS were significantly improved in stream water due to the presence of the Dangsan forests and the RCF. The role of Dangsan forests and the RCF was evident in the conservation of stream landscape and rural culture as well as in maintaining stream water quality. The management schemes of the streams with Dangsan forests and the RCF's are also suggested.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.4
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• pp.375-390
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• 2009

Statement of problem: Implant supported overdenture is accepted widely as a way to restore edentulous ridge providing better retention and support of dentures. Various types of attachment for overdenture have been developed. Purpose: The purpose of this study was to investigate the influence of attachment type in implant overdentures on the biomechanical stress distribution in the surrounding bone, prosthesis and interface between implant and bone. Material and methods: Finite element analysis method was used. Average CT image of mandibular body(Digital $Korea^{(R)}$, KISTI, Korea) was used to produce a mandibular model. Overdentures were placed instead of mandibular teeth and 2mm of mucosa was inserted between the overdenture and mandible. Two implants($USII^{(R)}$, Osstem, Korea) were placed at both cuspid area and 4 types of overdenture were fabricated ; ball and socket, Locator, magnet and bar type. Load was applied on the from second premolar to second molar tooth area. 6 times of finite element analyses were performed according to the direction of the force $90^{\circ}$, $45^{\circ}$, $0^{\circ}$ and unilateral or bilateral force applied. The stress at interface between implants and bone, and prosthesis and the bone around implants ware compared using von Mises stress. The results were explained with color coded graphs based on the equivalent stress to distinguish the force distribution pattern and the site of maximum stress concentration. Results: Unilateral loading showed that connection area between implant fixture and bar generated maximum stress in bar type overdentures. Bar type produced 100 Mpa which means the most among 4 types of attachments. Bilateral loading, however, showed that bar type was more stable than other implants(magnet, ball and socket). 26 Mpa of bar type was about a half of other types on overdenture under $90^{\circ}$ bilateral loading. Conclusions: In any directions of stress, bar type was proved to be the most vulnerable type in both implants and overdentures. Interface stress did not show any significant difference in stress distribution pattern.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.276-285
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• 1998

The aboveground biomass and nutrient content (N, P, K, Ca and Mg) of Pinus koraiensis S. et Z., aged 9, 22, 34, 46, 66 years, were measured in the Experiment Forest of Kangwon National University of Kangwondo province. The site index of the stands ranged from 13.5 to 14.2. Allometric equations (logY=alogX+b, where Y, X is ovendry mass and DBH, respectively) relating dry weights of stem, branches and needles to diameter at breast height (DBH) were developed to estimate aboveground tree biomass. Total above ground tree biomass increased with stand age from $21.8t\;ha^{-1}$ in the 9-year-old stand to $130t\;ha^{-1}$ in the 66-Year-old stand. Aboveground biomass was allocated as follows : stem> branch > foliage, except for the 9-year-old stand which had a greater proportion of foliage biomass than branch biomass. As stand age increased, an increasing proportion of annual biomass increment was allocated to stems. The aboveground biomass of shrubs and herbs ranged from 0.4 to $3.9t\;ha^{-1}$ and from 0.05 to $0.6t\;ha^{-1}$, respectively. No relationship was found between aboveground understory biomass and stand age. The mass of woody debris and forest floor varied between 0.59 to $1.54t\;ha^{-1}$ and 6.0 to $21.63t\;ha^{-1}$, respectively. Nutrient accumulation in aboveground tree biomass increased with stand age and was in the order of N > Ca > K > P > Mg. Average rates of nutrients accumulation in biomass were greatest in the early stages of stand development, and less marked as stand aged. The nutrient concentrations in different tree components decreased in the order of needle > branch > stem. There were no detectable trends in nutrient content of the forest floor and mineral soils with stand age. Understory vegetation contributed little to the nutrient pool of these Korean pine ecosystems. Mineral soil contained the Breast proportion of nutrient capital of the various ecosystem compartments.

• Investigative Magnetic Resonance Imaging
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• v.18 no.3
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• pp.232-243
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• 2014

Purpose : To evaluate the incidence of secondary contiguous or non-contiguous subchondral bone impactions (SBI) in subaxial cervical spinal injury and associated primary injury patterns. Materials and Methods: A retrospective review of computed tomography, magnetic resonance imaging, and medical records was carried out for 47 patients who had sustained a subaxial cervical spinal injury. Presence, number, level, and sites of secondary contiguous or non-contiguous SBI were recorded. To evaluate primary injury patterns, the level and number of primary injury sites of subaxial cervical spine injury, injury morphology, anterior/posterior discoligamentous complex (ADC/PDC) injury, posterior ligamentous complex (PLC) injury, spinal cord injury, and mechanism of injury (MOI) were analyzed. Differences in primary injury pattern of subaxial cervical spine injury and MOI between patients with and without SBI, and between contiguous or non-contiguous SBI were analyzed using the Mann-Whitney U test, Pearson's chi square test and Fisher's exact test. Results: Eighteen patients (18/47, 38.29%) had developed contiguous (n=9) or non-contiguous (n=9) SBI, most commonly involving T3 (15/47, 31.91%) and 3 levels (6/18, 33.33%). All SBIs had developed near the anterosuperior region of the body and the superior endplate and were the result of a high-impact MOI. SBIs were statistically significant in association with injury morphology and PLC injury (P=0.001, P=0.009, respectively) at the primary injury site. Non-contiguous SBI was more frequently accompanied by upper cervical spinal injuries in association with PDC injuries, as opposed to contiguous SBI, with statistical significance (P=0.009), while no other statistically significant differences were found. Conclusion: Secondary SBIs are common and probably associated with subaxial cervical spinal injuries with high energy compressive flexion forces.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.2
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• pp.94-101
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• 2015

To mitigate the greenhouse gas emission, many carbon capture and storage projects are underway all over the world. In Korea, many studies focus on the storage of $CO_2$ in the offshore sediment. Assurance of safety is one of the most important issues in the geological storage of $CO_2$. Especially, the assessment of possibility of leakage and amount of leaked $CO_2$ is very crucial to analyze the safety of marine geological storage of $CO_2$. In this study, the leakage of injected $CO_2$ through fault was numerically studied. TOUGH2-MP ECO2N was used to simulate the subsurface behavior of injected $CO_2$. The storage site was 150 m thick saline aquifer located 825 m under the continental shelf. It was assumed that $CO_2$ leak was happened through the fault located 1,000 m away from the injection well. The injected $CO_2$ could migrate through the aquifer by both pressure difference driven by injection and buoyancy force. The enough pressure differences made it possible the $CO_2$ to migrate to the bottom of the fault. The $CO_2$ could be leaked to seabed through the fault due to the buoyancy force. Prior to leakage of the injected $CO_2$, the formation water leaked to seabed. When $CO_2$ reached the seabed, leakage of formation water stopped but the same amount of sea water starts to flow into the underground as the amount of leaked $CO_2$. To analyze the effect of injection rate on the leakage behavior, the injection rate of $CO_2$ was varied as 0.5, 0.75, and $1MtCO_2/year$. The starting times of leakage at 1, 0.75 and $0.5MtCO_2/year$ injection rates are 11.3, 15.6 and 23.2 years after the injection, respectively. The leakage of $CO_2$ to the seabed continued for a period time after the end of $CO_2$ injection. The ratios of total leaked $CO_2$ to total injected $CO_2$ at 1, 0.75 and $0.5MtCO_2/year$ injection rates are 19.5%, 11.5% and 2.8%, respectively.