• Asian Pacific Journal of Cancer Prevention
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• v.17 no.10
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• pp.4735-4739
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• 2016

Background: Intrahepatic cholangiocarcinoma (IHCCA) is an aggressive tumor for which surgical resection is a mainstay of treatment. However, recurrence after resection is common associated with a poor prognosis. Studies regarding recurrence of mass-forming IHCCA are rare; therefore, we investigated the pattern with our dataset. Methods: We retrospectively reviewed the medical and pathological records of 50 mass-forming IHCCA patients who underwent hepatic resection between January 2004 and December 2009 in order to determine the patterns of recurrence and prognosis. All demographic and operative parameters were analyzed for their effects on recurrence-free survival. Results: The median recurrence-free survival time was 188 days (95%CI: 149-299). The respective 1-, 2-, and 3-year recurrence-free survival rates were 16.2% (95%CI: 6.6-29.4), 5.4% (95%CI: 1.0-15.8) and 2.7% (95%CI: 0.2-12.0). There was an equal distribution of recurrence at solitary and multiple sites. Univariate analysis revealed no factors related to recurrence-free survival.Conclusion: The overall survival and recurrence-free survival after surgery for mass-forming IHCCA were found to be very poor. Almost all recurrences were detected within 2 years after surgery. Adjuvant chemotherapy after surgery may add benefit in the affected patients.

• Journal of Preventive Medicine and Public Health
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• v.49 no.4
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• pp.230-239
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• 2016

Objectives: We aimed to evaluate the effect of geographic units of analysis on measuring geographic variation in medical services utilization. For this purpose, we compared geographic variations in the rates of eight major procedures in administrative units (districts) and new areal units organized based on the actual health care use of the population in Korea. Methods: To compare geographic variation in geographic units of analysis, we calculated the age-sex standardized rates of eight major procedures (coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, surgery after hip fracture, knee-replacement surgery, caesarean section, hysterectomy, computed tomography scan, and magnetic resonance imaging scan) from the National Health Insurance database in Korea for the 2013 period. Using the coefficient of variation, the extremal quotient, and the systematic component of variation, we measured geographic variation for these eight procedures in districts and new areal units. Results: Compared with districts, new areal units showed a reduction in geographic variation. Extremal quotients and inter-decile ratios for the eight procedures were lower in new areal units. While the coefficient of variation was lower for most procedures in new areal units, the pattern of change of the systematic component of variation between districts and new areal units differed among procedures. Conclusions: Geographic variation in medical service utilization could vary according to the geographic unit of analysis. To determine how geographic characteristics such as population size and number of geographic units affect geographic variation, further studies are needed.

• Journal of Plant Biology
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• v.26 no.1
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• pp.17-32
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• 1983

The aboveground production, nutrient distribution and nutrient cyclings were compared between two Phragmites communis communities growing in the different salt contents of soil in a coastal salt marsh. Inorganic nutrient contents of soil for plant growth were greater at the low salt stand than at the high salt stand except for sodium(Na). Maximum aboveground biomass of the plant at the low and the high salt stands were 2,533 and 1,719 g dw/$m^2$, respectively, in August. Seasonal changes of nutrient content of biomass in dry weight decreased with growth except for Na. Nutrient contents in biomass per unit land area increased continuously as biomass increases, although the amount of potassium(K) reached the maximum content in July and thereafter decreased. Vertical distributions of total nitrogen(T-N) and phosphorus(P) increased with plant height, but Na showed the reverse trend. That of K was similar to the patterns for T-N and P in the leaves, and to the pattern of Na in the stems. The Na was greatly accumulated in underground biomass but transported scarcely to aboveground. At the low and the high salt stands, the ratios of the inorganic nutrients contained in the plant were 100 : 66 for T-N, 100 : 61 for P, 100 : 62 for K and 100 : 97 for Na. the ratios of the amounts of nutrients retrieved to soil were 100 : 242 for T-N, 100 : 408 for P, 100 : 127 for K and 100 : 269 for Na, respectively. Turnover times of the T-N, P, K and Na in the communities were 56, 1, 15 and 174 years at the low salt stand, and 75, 2, 24 and 323 years at the high salt stand, respectively. In nutrient cyclings, all of the nutrients retrieving to soil were less than uptake by plant. Among the nutrient, especially P is expected to be exhausted from soil, sooner or later, because of the harvest by men.

• Journal of the Korean Society for Library and Information Science
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• v.19
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• pp.189-241
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• 1990

This study identified cognitive styles of online searchers in terms of Field Dependence (FD) and Field Independence (FI) dimension and determined whether searching performance was affected by FD / FI cognitive differences between online searchers and the extent to which searching performance was affected by the FD / FI dimension of cognitive style. This study used a quasi experimental design with 41 student subjects using the Lockheed DIALOG system and ERIC ONT AP database. Cognitive styles of student subjects were measured by using GEFT (Group Embedded Figure Test) and the subjects were divided into two cognitive groups- FD and FI based on the GEFT scores. Each subject was assigned two predetermined searches which had different search goals-a 'high precision search' and a 'high recall search.' Search performance of the two cognitive groups on the two problems was compared in order to see how these two groups responded to achieving different search goals in terms of search strategy, search inputs, and resulting search outputs. The major findings of this study were: 1. The pattern of approaching a search problem regardless of whether it was a high precision search or a high recall search was not significantly different between the two cognitive groups. 2. The FI group tended to use significantly more terms for the high recall search than the FD group but slightly less time than the FD group. However, significant differences in connect time between the two groups were not revealed. 3. For both search problems the FI group achieved a significantly higher success rate than the FD group. The FI group were significantly more successful searchers than the FD group. As for unit / cost, although the FI group were more cost effective than those of the FD group for both searches, these differences were too small to be statistically significant. 4. Mean differences of the search performance variables between the FD / FI groups were consistent across the two types of search questions. The FI group seemed to be equally effective for both types of search questions. In conclusion, the differences found in number of terms used and success rate between the two cognitive groups apparently resulted from different cognitive styles.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.4
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• pp.611-624
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• 1993

The purpose of this study was to analyze the stress distribution of the natural teeth, the implant, the prosthesis and the supporting tissue according to the types of implant and connection modality in the five-unit fixed partial denture with a implant pier abutment. A Two dimensional stress analysis model was constructed to represent a mandible missing the first and second premolars and first molar. The model contained a canine and second molar as abutment teeth and implant pier abutments with and without stress-absorbing element. Finite element models were created and analyzed using software ANSYS 4.4A for IBM 32bit personal computer. The results obtained were as follows. 1. Implant group, compared to the natural teeth group, showed a maximum principal stress at the superior portion of implants and a stress concentration at :he neck and end portion. 2. Maximum principal stress and maximum Von Mises stress were always lower in the case of rigid connection than nonrigid connection. 3. A cylinder type implant with stress absorbing element and screw type implant were generally similar in the stress distribution pattern. 4. A screw type implant, compared to the cylinder type implant, showed a relatively higher stress concentration at both neck and end portion of it. 5. Load B cases showed higher stress concentration on the posterior abutments in the case of nonrigid connector than rigid connector. 6. A maximum displacement was always lower in the case of rigid connection than nonrigid connection. These results suggest that osseointegrated implant can be used as an intermediate abutment.

• Journal of Environmental Science International
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• v.18 no.5
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• pp.527-538
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• 2009

A village grove is the one fostered and protected for a district's traditional life near the vicinity of a ruderal village. This research is done to grasp potential natural vegetation, to use a basis data needed for its management and preservation as well as restoration project by examining the vegetation and flora targeting a village grove of the southern district of Gyeonggi-do which has been seriously damaged subsequent to a rapidly progressing city development. According to the survey, there appeared an outgrowth flora of Pteridophyta consisting of 69 families, 136 genera, 20 varieties, 3 forms, 170 species-totalling to 193 taxa. Urbanization index was revealed to 4.55% and naturalization rate 6.74%. In life-cycle pattern, perennials were found to show the highest distribution rate; in infiltration-multiplication strategies, human wave tactics type was found to be the highest 51%, consisting of 98 species, and naturalization rate also was revealed to be 6.74%. The vegetation unit was divided into a total of 11 patterns, such as a community of Pinus densiflora community, Pinus densiflora-Pinus rigida community, Pinus densiflora-Castanea crenata community, Pinus rigida community, Pinus rigida-Castanea crenata community, Pinus rigida-Quercus acutissima community, Castanea crenata community, Castanea crenata-Quercus acutissima community, Quercus acutissima community, Quercus acutissima-Robinia pseudo-acacia community and Robinia pseudo-acacia community. Quercus acutissima community is of a community type dominated by Quercus acutissima, in place of Pinus densiflora community selected by natural succession.

• The korean journal of orthodontics
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• v.47 no.1
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• pp.11-20
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• 2017

Objective: This randomized controlled trial aimed to compare the stability of mandibular arch orthodontic treatment outcomes between passive self-ligating and conventional systems during 6 months of retention. Methods: Forty-seven orthodontic patients with mild to moderate crowding malocclusions not requiring extraction were recruited based on inclusion criteria. Patients (mean age $21.58{\pm}2.94years$) were randomized into two groups to receive either passive self-ligating ($Damon^{(R)}$ 3MX, n = 23) or conventional system (Gemini MBT, n = 24) orthodontic treatment. Direct measurements of the final sample comprising 20 study models per group were performed using a digital caliper at the debonding stage, and 1 month, 3 months, and 6 months after debonding. Paired t-test, independent t-test, and non-parametric test were used for statistical analysis. Results: A significant increase (p < 0.01) in incisor irregularity was observed in both self-ligating and conventional system groups. A significant reduction (p < 0.01) in second interpremolar width was observed in both groups. Mandibular arch length decreased significantly (p = 0.001) in the conventional system group but not in the self-ligating system group. A similar pattern of stability was observed for intercanine width, first interpremolar width, intermolar width, and arch depth throughout the 6-month retention period after debonding. Comparison of incisor irregularity and arch dimension changes between self-ligating system and conventional system groups during the 6 months were non-significant. Conclusions: The stability of treatment outcomes for mild to moderate crowding malocclusions was similar between the self-ligating system and conventional system during the first 6 months of retention.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.2
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• pp.125-145
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• 2001

To compare the stress distribution patterns between cement-retained and screw-retained implant supported fixed prostheses according to four different abutment types, a three dimensional finite element analysis was performed. The hypothetical three unit fixed partial denture case was modelled on the three implants(10mm length and 3.75 diameter) in mandibular bone. Four angles of implantation(vertical, 10, 15 and 20 degree inclined mesially) were created and three different directions of force (vertical, oblique, horizontal) were applied at the center of the second premolar and distal end of the first molar for each cases. Within the limits of this study, the results were as follows, 1. In vertically installed cases, the more stress was concentrated at upper components, but mesially inclined cases, the more stress was concentrated at cortical bone. 2, The more inclined mesially the more stress was observed, especially at cortical bone. 3. The cement-retained models showed lower principal stress and more even stress distribution than the screw-retained models. 4. The similar stress distribution pattern was showed in model 1 and model 2, model 3 and model 4. 5. The more stress was observed when the loads were applied at the distal end of 1st molar than the center of 2nd premolar. 6 The fixture and the model as a whole, lesser stress values were observed when vertical loads were applied as compared to horizontal and oblique loads.

• Journal of Dental Rehabilitation and Applied Science
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• v.20 no.2
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• pp.71-81
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• 2004

The purpose of this study was to compare the distributing pattern of stress on the finite element models of two units implant prosthesis with one angulated placement of two implant fixtures. The two unit implant crowns simulated to mandibular first and second molars were made. The two kinds of finite element models were designed according to angulation of fixture ($4.0mm{\times}11.5mm$) : Model 1($15^{\circ}$ buccally angulated placement of one fixture on second molar area), Model 2($15^{\circ}$ lingually angulated placement of one fixture on second molar area). Axial loads of 200N were applied to the center of central fossa and to distance of 2mm and 4mm apart from the center of central fossa. Von-Mises stresses were recorded and compared in the fixtures, and buccolingual section of implants. The results were as follows: 1. Under axial loading at the central fossa, the stress was distributed along the straight fixture except apical portion, while on buccally or lingually angulated placement, the highest stresses were concentrated in the neck portion on the opposite side of the angulated fixture. 2. With offset distance increasing, the stresses were concentrated greater in buccal neck of lingually angulated fixture than in lingual neck of buccally angulated fixture. From the above results, in designing of the occlusal scheme for implant prosthesis with the angulated fixture, occlusal contacts should be placed to distribute stress axially in maximum intercuspation and to avoid offset force during eccentric movements.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.11
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• pp.1051-1061
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• 2004

In this Paper, a new antenna(VHMDA) characteristics of half-circular/elliptical disc-loaded planar antennas with horizontally top-loaded small disc is studied by simulation and measurements with additional resonant structure. The transfer function characteristics of Gaussian pulse from the designed UWB transmitter antenna has been investigated. The radiation pattern of the proposed antenna in azimuth is nearly omni-directional response, which is usulally required in conventional monopole antenna. In addition to that, the simulation and measured results show that the return loss characteristics of VHDMA covers considerably large bandwidth with small area. From the measured results of the circular and half-circular disc-loaded monopole antennas with small disc mounted on the top, it is found that the half disc-loaded monopole antenna with additional structure can be comparable to the circular disc-loaded monopole antenna in respect o( size and electrical performances. Surface wave and dielectric losses often caused by the printed antenna using high dielectric constant does not occur in metallic planar antenna with good impedance matching and without lossy matching unit. This structure implies that the performance of return loss is directly related with the radiation efficiency.