• KDI Journal of Economic Policy
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• v.30 no.2
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• pp.225-270
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• 2008

We analyze macroeconomic consequences of pay-as-you-go (PAYGO) public pension system with a simple overlapping generations model. Contrary to large body of existing literatures offering quantitative results based on simulation study, we take another route by adopting a highly simplified framework in search of qualitatively tractable analytical results. The main contribution of our results lies in providing a sound theoretical foundation that can be utilized in interpreting various quantitative results offered by simulation studies of large scale general equilibrium models. We present a simple overlapping generations model with a defined benefit(DB) PAYGO public pension system as a benchmark case and derive an analytical equilibrium solution utilizing graphical illustration. We also discuss the modifications of the benchmark model required to encompass a defined contribution(DC) public pension system into the basic framework. Comparative statics analysis provides three important implications; First, introduction and expansion of the PAYGO public pension, DB or DC, result in lower level of capital accumulation and higher expected rate of return on the risky asset. Second, it is shown that the progress of population aging is accompanied by lower capital stock due to decrease in both demand and supply of risky asset. Moreover, risk premium for risky asset increases(decreases) as the speed of population aging accelerates(decelerates) so that the possibility of so-called "the great meltdown" of asset market cannot be excluded although the odds are not high. Third, it is most likely that the switch from DB PAYGO to DC PAYGO would result in lower capital stock and higher expected return on the risky asset mainly due to the fact that the young generation regards DC PAYGO pension as another risky asset competing against the risky asset traded in the market. This theoretical prediction coincides with one of the firmly established propositions in empirical literature that the currently dominant form of public pension system has the tendency to crowd out private capital accumulation.

• Korean Journal of Environment and Ecology
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• v.26 no.1
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• pp.46-56
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• 2012

Benthic macroinvertebrates were investigated in Hoeongseong Lake region from March to October 2010, Korea. Macroinvertebrate communities, composition of the functional feeding groups, habitiat oriented groups and the biological water quality were assessed above and below Hoeongseong Dam in the lake region. Six sites, two (St.1~2) above the lake, two (St. 3~4) into the lake, and two (St. 5~6) below the dam, were selected for quantitative (Surber sampler $30cm{\times}30cm$, mesh size 0.2 mm) and qualitative (Hand net) samplings of benthic macroinvertebrates. As a result, a total of 83 species belonging to 43 families, 17 orders, 8 classes, and 5 phyla were recognized. The EPT-group (50 spp. : 60.24%) that is major taxa or EPT-group plus Diptera (61 spp. : 73.49%) occupied most of benthic macroinvertebrates community. Based on quantitative sampling, the number of benthic maroinvertebrates above the lake was 2,399 individuals including 54 species, 28 families, 11 orders, 4 classes, and 4 phyla, whereas 510 individuals including 16 species, 12 families, 7 orders, 4 classes, and 3 phyla in the lake and 626 individuals including 62 species, 33 families, 13 orders, 6 classes, and 4 phyla below the dam were collected respectively. Dominance index was the highest, with 0.82-0.93 ($0.87{\pm}0.05$) in Hoeongseong lake (St. 3-4), diversity index was 3.04-3.16 ($3.10{\pm}0.06$), evenness index was 0.79-0.85 ($0.82{\pm}0.03$), and richness index was 7.27-8.52 ($7.90{\pm}0.63$), which were relatively higher below the dam sites. In the functional feeding groups, collector-gatherers and collector-filterers were the highest in the whole sites, and predators (Micronecta sedula) was appeared highly in the lake. Moreover, swimmers, burrowers, and clingers were considerably occupied in all collecting sites. The result of the DCA, similarity analysis, and MRPP were well reflective of the composition of lake and stream macroinvertebrates. ESB indicate that the lake sites were evaluated heavily polluted under priority improvement waters. Also, Semisulcospira gottschei, Ecdyonurus kibunensis, Epeorus pellucidus, Rhoenanthus coreanus, Stenelmis sp., and Cheumatopsyche brevilineata are considered as an indicator species above and below Hoeongseong Lake, whereas Macrobrachium nipponense and Micronecta sedula are indicated in the lake.

• Korean Journal of Environment and Ecology
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• v.31 no.2
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• pp.252-265
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• 2017

This study aims to analyze the landscape ecological characteristics of green spaces within built up area of high density and evaluate the potential applicability of green patches, thereby introducing urban garden for generating green networks in residence areas. To this end, Yeoksam-Dong was selected as the site area since it is classified as both green initiative zone and alienated area of park service in Seoul. First, the current condition of green spaces in Yeoksam-Dong was identified by five categories: Street trees, private garden, public pocket garden, rooftop garden, and park. Then, the landscape index analysis through FRAGSTATS and connectivity assessment via multi-buffer zone analysis were carried out for analyzing the green networks and evaluating the potential value of green space. The results showed that the degree to which green areas in the site were distributed is arranged in the order of street tree, private garden, public pocket garden, park, and rooftop garden. In case of the street trees whose total core area (TCA, $1,618m^2$) is as high as the park's ($1,128m^2$). Private garden has potential for green network in built up area of high density by gardening since the shape of the patches are irregular (ED = 78.1m/ha) and the average distance among the patches is close (ENN=33.9m). Public pocket garden has also potential for gardening according to the result that it was found to be distributed evenly (LPI=5.7%, SHEI=0.9) with exposing external disturbance ($TCA=66m^2$). For the green network, 84% of all the study site is covered by small green network in 50m butter range of connected green area. The effect of green network was expected through gardening in public pocket garden (27%) and street tree (26%). Accordingly, it is encouraged to actively utilize street tree, private gardens, and rooftop gardens and to establish the urban gardens like local-based community gardens in public pocket garden where a variety of activities can be carried out near residential areas. By doing so, green networks can effectively be established in built up area with high density. The results of this study can contribute positively to fostering the creation of various types of urban gardens.

• Progress in Medical Physics
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• v.23 no.2
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• pp.106-113
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• 2012

The purpose of this study is to evaluate the variation of radiation dose distribution for liver tumor located in liver dome and for the interest organs(normal liver, kidney, stomach) with the pencil beam convolution (PBC) algorithm versus anisotropic Analyticalal algorithm (AAA) of the Varian Eclipse treatment planning system, The target volumes from 20 liver cancer patients were used to create treatment plans. Treatment plans for 10 patients were performed in Stereotactic Body Radiation Therapy (SBRT) plan and others were performed in 3 Dimensional Conformal Radiation Therapy (3DCRT) plan. dose calculation was recalculated by AAA algorithm after dose calculation was performed by PBC algorithm for 20 patients. Plans were optimized to 100% of the PTV by the Prescription Isodose in Dose Calculation with the PBC algorithm. Plans were recalculated with the AAA, retaining identical beam arrangements, monitor units, field weighting and collimator condition. In this study, Total PTV was to be statistically significant (SRS: p=0.018, 3DCRT: p=0.006) between PBC and AAA algorithm. and in the case of PTV, ITV in liver dome, plans for 3DCRT were to be statistically significant respectively (p=0.013, p=0.024). normal liver and kidney were to be statistically significant (p=0.009, p=0.037). For the predictive index of dose variation, CVF ratio was to be statistically significant for PTV in the liver dome versus PTV (SRS r=0.684, 3DCRT r=0.732, p<0.01) and CVF ratio for Tumor size was to be statistically significant (SRS r=-0.193, p=0.017, 3DCRT r=0.237, p=0.023).

• Progress in Medical Physics
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• v.25 no.4
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• pp.233-241
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• 2014

The aim of this study is to develop a new software tool for 3D dose verification using $PRESAGE^{REU}$ Gel dosimeter. The tool included following functions: importing 3D doses from treatment planning systems (TPS), importing 3D optical density (OD), converting ODs to doses, 3D registration between two volumetric data by translational and rotational transformations, and evaluation with 3D gamma index. To acquire correlation between ODs and doses, CT images of a $PRESAGE^{REU}$ Gel with cylindrical shape was acquired, and a volumetric modulated arc therapy (VMAT) plan was designed to give radiation doses from 1 Gy to 6 Gy to six disk-shaped virtual targets along z-axis. After the VMAT plan was delivered to the targets, 3D OD data were reconstructed from 512 projection data from $Vista^{TM}$ optical CT scanner (Modus Medical Devices Inc, Canada) per every 2 hours after irradiation. A curve for converting ODs to doses was derived by comparing TPS dose profile to OD profile along z-axis, and the 3D OD data were converted to the absorbed doses using the curve. Supra-linearity was observed between doses and ODs, and the ODs were decayed about 60% per 24 hours depending on their magnitudes. Measured doses from the $PRESAGE^{REU}$ Gel were well agreed with the TPS doses at central region, but large under-doses were observed at peripheral region at the cylindrical geometry. Gamma passing rate for 3D doses was 70.36% under the gamma criteria of 3% of dose difference and 3 mm of distance to agreement. The low passing rate was resulted from the mismatching of the refractive index between the PRESAGE gel and oil bath in the optical CT scanner. In conclusion, the developed software was useful for 3D dose verification from PRESAGE gel dosimetry, but further improvement of the Gel dosimetry system were required.

• Investigative Magnetic Resonance Imaging
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• v.2 no.1
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• pp.14-30
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• 1998

Manganese is an essential element in the body. It is mainly deposited in the liver and to a lesser degree in the basal ganglia of the brain and eliminated through the bile duct. Rapid turnover of managanese in the body makes it difficult to evaluate the manganese exposure in workers, esecially in those with irregular or intermittent exposure, like welders. Therefore, conventional biomarkers, including blood and urine manganese can provide only a limited information about the long-tern or cumulative exposure to manganese. Introduction of magnetic resonance imaging (MRI) made a progress in the assessment of manganese exposure in the medical conditions related to manganese accumulation, e. g. hepatic failure and long-term total parenteral nutrition. Manganese shortens spin-lattice(T1) relaxation time on MRI due to its paramagnetic property, resulting in high signal intensity (HSI) on T1-weighted image(T1W1) of MRI. Manganese deposition in the brain, therefore, can be visualizedas an HSI in the globus pallidus, the substantia nigra, the putamen and the pituitary. clinical and epidemiologic studies regarding the MRI findings in the cases of occupational and non-occupational manganese exposure were reviewed. relationships between HSI on T1W1 of MRI and age, gender, occupational manganese exposure, and neurological dysfunction were analysed. Relationships betwen biological exposure indices and HSI on MRE werealso reviewed. Literatures were reviewed to establish the relationships between HSI, Manganese deposition in the brain, pathologic findings, and neurological dysfunction. HSI on T1W1 of MRI reflects regional manganese deposition in the brain. This relationship enables an estimation of regional manganese deposition in the brain by analysing MR signal intensity. Manganese deposition in the brain can induce a neuronal loss in the basal ganglia but functional abnormality is supposed to be related to the cumulative exposure of manganese in the brain, use of brain MRI for the assessment of exposure in a group of workers seems to be hardly rationalized, while ti can be a useful adjunct for the evaluation of manganese exposure int he cases with suspected manganese-related health problems.

• Sijohaknonchong
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• v.44
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• pp.197-236
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• 2016

The aim of this study is to discover the distinctive aspects of Sijo in the 17th Century through five old music scores, "梁琴新譜Yangqeumsinbo", "白雲庵琴譜 baekwoonamgeumbo", "增補古琴譜jeungbogogeumbo", "延世大學校所藏琴譜geumbo in Yonsei University", "琴譜古geumbogo", which were compiled in this time period. First, four Sijo works are found from the "梁琴新譜Yangqeumsinbo" and one of them is noteworthy because it was sung as 中大葉Jungdaeyeop, 初中大葉 Chojungdaeyeop, 二中大葉Yijungdaeyeop and showed signs to fit the Sijo format type since the 17th century. In "白雲庵琴譜baekwoonamgeumbo", there are three Sijo works (one has recorded music scores and two don't) and one of them is discovered with last phrase being omitted. In "延世大學校所藏琴譜geumbo in Yonsei University", there are 9 Sijo works performed with 中大葉Jungdaeyeop. In "增補古琴譜 jeungbogogeumbo", there are three works performed with 數大葉Sakdaeyeop and one of them is noteworthy as a clue about the relations between Sijo and Goryeosokyo because it is a modified work which adapted the Goryeosokyo "Gasiri" according to the Sijo format. In 琴譜古geumbogo, there are three works with high possibility that repertoire with 中大葉Jungdaeyeop were already set up at this time. Based on these five music scores, it can be mentioned that a lot of Geumbos were compiled in 17th century, not for the purpose of enlightening discourse at the national level but for referencing for music lovers by themselves to memorize songs individually. It is also discovered that Sijo was performed with only 平調pyeong-jo out of 羽調woo-jo, 羽調界面調woojokyemyen-jo, 平調pyeong-jo, 平調界面調pyeongjokyemyun-jo in early 17th century, but it was performed with other three and 數大葉Sakdaeyeop as well after the mid-17th century. On the other hand, despite the change in the musical tunes, lyrics do not show a significant change at this time because it is estimated repertoire with specific piece of music was already formed in 17th Century. However, performing itself would give a certain impact on change and loss of lyrics because it tends to focus on communication and emotional connection between singers and audience. Clarifying characteristics in Sijo from old music scores is meaningful in that Sijo can be understood better not only as written poetry but also as oral poetry and overcome bias of previous researches which have been proceeded mainly on Sijo lyrics collection(歌集).

• Journal of the Korea Society of Computer and Information
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• v.18 no.1
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• pp.167-175
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• 2013

This study set out from the perception that one should develop and activate differentiated programs from those 5 programs of the Health Family Support Center (family counseling program, family education support project, family affinity culture support project, care support project, diversity family support project) on the subjects (n=299) of residents in G metropolitan city by reflecting the levels of family values, communication between family members and family relationship. To achieve the study purposes above, this study devised research questions as follows: Research question 1. What are the levels of local residents for their family values, communication between family members and family relationship? Research question 2. Is there any difference in demanding family support project programs according to the local residents' family values, communication between family members and family relationship? Following are the results of this study: First, the levels were analyzed to be more than the average (on a maximum scale of 5 points) with local residents' family values (M=3.55, S.D.=.664), communication between family members (M=3.65, S.D.=.669), family relationship (M=3.69 S.D=.584) Second, the necessity levels for family values, communication between family members and family relationship of the group below the average as compared with the group over the average was found to be significantly high in family education support project, family affinity culture support project, care support project and diversity family support project except family counseling program. Accordingly, strategic plans for increasing the participation rate for the programs by the Health Family Support Center and activating those programs could be by investigating in advance the levels of family values, communication between family members and family relationship by each program respectively and differentiating the target level for the program by the group, or by giving preference to the group below the average who have high needs of program necessity when making decisions for the participation preference of the programs.

• Journal of the Korea Society of Computer and Information
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• v.18 no.2
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• pp.149-156
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• 2013

In this paper, the Constitutional Court's ruling through the SNS was virtually guaranteed the freedom of election campaign through, though, still a large portion of campaign restrictions on public election law provisions exist to this forward in the election is likely to cause a lot of legal problems. In this paper, the Constitutional Court's ruling through the SNS was virtually guaranteed the freedom of election campaign through, though, still a large portion of campaign restrictions on public election law provisions exist to this forward in the election is likely to cause a lot of legal problems. Moreover, in the mean time the campaign and which in the course of the election campaign through the SNS, the infinite potential of the growing point than any point spread from the SNS and freedom of election campaign through public election law with regard to the limitation of the diffusion of false facts, awards, a number of problems are likely to occur. You've been in this business and disseminate false guilt disparage precandidacy for true-false, as well. He should be able to reach a specific goal you want to defeat through the dissemination of information which is specified as a crime for this strictly for the fact that disseminate false, rather than to interpret it is the judgment of the Court in that judgment against have been made. Therefore, this strict interpretation of the law and the need to revise or delete before I would like to discuss about. The legislation would repeal the cull of Ron sang first of all point out the issue through analytics. First, the purpose of the data protection Act provides limited interpretation to fit in this world of sin. Secondly, this sin is committed for the purpose of prevention, since the purpose of the objective in this case of sin and the need to interpret strictly. Why I am the Internet space in the case of so-called tweets from followers, this means in some cases done without a lot of the stars because of this, there will be a limit to the punishment of sin, this is obvious. And, in the long-awaited Constitutional Court ensures the freedom of election campaign through SNS and free election in the country, even in the limited sense interpretation opens the chapter of communication is needed. This ensured the freedom of expression will be highly this is a mature civil society that will be imperative.

• Clinical and Experimental Reproductive Medicine
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• v.35 no.2
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• pp.155-162
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• 2008

Objectives: The aim of this study was to assess the change of ovarian reserve after removal of ovarian tumor using basal FSH, $E_2$, clomiphene citrate challenge test and ovarian volume. Methods: Twenty two patients with unilateral ovarian tumor, ${\leq}35$ years old, regular menstrual cycle were collected prospectively and divided into endometrioma or non-endometrioma group. We measured the ovarian volume with transvaginal ultrasonography on the day 3 of menstrual cycle within one month before and 3 months after surgery. Basal (cycle day 3) FSH, $E_2$ and CCCT were checked before surgery and repeated at least 2 spontaneous cycles later after surgery. Three patients that had been pregnant within 3 months after surgery were excluded in analysis. Results: The ovarian volume was reduced significantly after surgery in endometrioma and non-endometrioma ${\geq}10\;cm$ group ($4.79{\pm}2.57\;cm^3$ and $5.21{\pm}1.33\;cm^3$, respectively), but not in the non-endometrioma <10 cm group ($6.18{\pm}2.85\;cm^3$). After surgery, basal FSH and cycle day 10 FSH on CCCT in endometrioma and non-endometrioma were $4.25{\pm}0.20\;mIU/ml$ and $3.79{\pm}0.80\;mIU/ml$, $4.24{\pm}0.85\;mIU/ml$ and $4.28{\pm}0.92\;mIU/ml$, respectively. There were neither significant difference in comparison with the preoperative results nor between two groups. Conclusions: Enucleation of ovarian mass was associated with a significant reduction in ovarian volume in endometrioma and non-endometrioma larger than 10cm in diameter. Hormonal markers for evaluation of ovarian reserve, such as basal and cycle day 10 FSH on CCCT, were not changed significantly in each group. In reproductive age women, conservative enucleation or cystectomy rather than oophorectomy should be considered even in a large benign tumor and ovarian function could be reserved by meticulous operative technique.