• Investigative Magnetic Resonance Imaging
• /
• v.14 no.1
• /
• pp.31-40
• /
• 2010

Purpose : To compare the relative values of various fast breath-hold imaging sequences for superparamagnetic iron-oxide (SPIO)-enhanced hepatic MRI for the assessment of solid focal lesions with a 3T MRI unit. Materials and Methods : 102 consecutive patients with one or more solid malignant hepatic lesions were evaluated by spoiled gradient echo (GRE) sequences with three different echo times (2.4 msec [GRE_2.4], 5.8 msec [GRE_5.8], and 10 msec [GRE_10]) for $T2^*$-weighted imaging in addition to T2-weighted turbo spin echo (TSE) sequence following intravenous SPIO injection. Image qualities of the hepatic contour, vascular landmarks and artifacts were rated by two independent readers using a four-point scale. For quantitative analysis, contrast-to-noise ratio (CNR) was measured in 170 solid focal lesions larger than 1 cm (107 hepatocellular carcinomas, nine cholangiocarcinomas and 54 metastases). Results : GRE_5.8 showed the highest mean points for hepatic contour, vascular anatomy and imaging artifact presence among all of the subjected sequences (p<0.001) and was comparable (p=0.414) with GRE_10 with regard to lesion conspicuity. The mean CNRs were significantly higher (p<0.001) in the following order: GRE_10 ($24.4{\pm}14.5$), GRE_5.8 ($14.8{\pm}9.4$), TSE ($9.7{\pm}6.3$), and GRE_2.4 ($7.9{\pm}6.4$). The mean CNRs of CCCs and metastases were higher than those of HCCs for all imaging sequences (p<0.05). Conclusion : Regarding overall performances, GRE using a moderate echo time of 5.8 msec can provide the most reliable data among the various fast breath-hold SPIO-enhanced hepatic MRI sequences at 3T unit despite the lower CNR of GRE_5.8 compared to that of GRE_10.

• Journal of The Korean Association For Science Education
• /
• v.22 no.1
• /
• pp.190-203
• /
• 2002

The purpose of this study is to test content validity of a portfolio assessment and to analyse the information which can be obtained from student portfolios. The content validity of the portfolio was tested against the objectives of each lesson and the emphasis of curriculum. The information was identified from the analysis of student portfolios. Students' portfolios from a fourth grade class in Pyeungteak, Kyeungki-do were used for analysis. The portfolios included students' evidence of learning on (I) Strata, Unit 2 'Strata and Fossil,' and (3) Change of Object by Heat, Unit 4 'Heat and Change of Object'. Fourth-grade science textbooks were also analyzed to understand the base level information for portfolio analysis. Two science education specialists and ten elementary teachers majored in science education took part in this analysis. The results of the analysis showed $70{\sim}100%$ of agreement between the objectives of lesson and portfolio forms. Over 90% of agreement is reached between portfolio forms and the emphasis of the curriculum. Student portfolios revealed much information on comprehension, observation, will to study, and process of learning. They also revealed some information on drawing conclusion, communication. self-direction, progress of learning, self-concept, interaction, and process of learning. As a whole, the information in students' portfolios is similar with that dealt in science textbooks. However, students' portfolios have more information on anticipation, will to study, self-direction, and interaction. On the contrary, science textbook deals more with information on observation, planning inquiry, than students' portfolios. The portfolio assessment examined has very sound content validity. The results also show that much more and various information which can not be obtained from pencil and paper test could be obtained from student portfolios. The use of information, obtained from student portfolios will make it possible understand students' learning. their strength and weakness, hence improve student' science learning.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.24 no.3
• /
• pp.73-97
• /
• 2013

This study examined Records Management(RM) practice of public enterprises supervised by National Archives of Korea(NAK). These enterprises are included among public institutions mandated to perform RM according to Public Records Management Act of 2006. The study performed telephone interviews of 8 records managers employed in public enterprises and investigated current status of RM practices, perception of the practices and records managers within the enterprises and treatment to them, as well as opinions of the NAK's assessment of RM in public institutions, While non-electronic records were managed in an appropriate manner, electronic records needed to be transferred, disposed of, and preserved properly. The majority of interviewees expressed positive opinions on the contribution of RM to effectiveness and transparency of the enterprises. However, RM was perceived as irksome work conducted by those in a low position. More interviewees were permanent contract workers or contract personnel than regular employees. They felt a sense of deprivation due to the discrepancy of annual incomes among public enterprises and the differences in treatment and attitude toward between contract workers and regular workers. Interviewees suggested that NAK's assessment of RM was useful since it provided a basis for RM in their institutions. Yet, they pointed out that its measurements were lack of consistency and relevance to public enterprises because those focused on RM in governmental organizations. They also noted that RM practices that the assessment do not cover might be ignored.

• Journal of Korea Port Economic Association
• /
• v.30 no.1
• /
• pp.159-173
• /
• 2014

This study is key competence port logistics companies analyze the priorities of evaluation factors. key competence index of NCS(National competency standard) was designed on the basis of the research model. The priorities of evaluation factors were analyzed using AHP method. The results of the analysis of 1 layer's key competence priorities are as follows: Interpersonal skills(0.217), communication skills(0.153), ability to develop problem(0.148), ability to understand the organization(0.103), and resource management skills(0.090), self-development ability and professional ethics(0.070), information skills(0.065), technical skills(0.049), numeracy skills(0.035).

• Journal of Korea Entertainment Industry Association
• /
• v.13 no.4
• /
• pp.341-348
• /
• 2019

The purpose of this study was to develop voluntary learning (talent donation) program as a liberal art lecture for students in G university to cultivate consideration towards others and community life. The title of the liberal education course that was developed was decided as "Beauty Talent Donation". The course objectives were to develop consideration for others and sociality required for community life as well as foster awareness of sharing and develop creative leaders equipped with outstanding characters through cosmetology voluntary service associated education. The final development of education contents were completed over 3 stages including preparation, development, and supplemented development and the major components consist of understanding talent donation, beauty theories, and beauty skills. For the assessment of the learners, absolute evaluation was applied so that personal goals can be achieved through the course instead of evaluating learners' learning capabilities with relative evaluation. Accordingly, a pass or fail system was designed. The beneficiary institution of talent donation was selected based on the following conditions. It is located within a short distance from the educational institution, walking distance for the learners, easy to recruit subjects to receive the support, and accurately understands the purpose of the lecture and willing to cooperate.

• Journal of Astronomy and Space Sciences
• /
• v.26 no.3
• /
• pp.305-316
• /
• 2009

In this study, we suggest an empirical forecast of CIR (Corotating Interaction Regions) and geomagnetic storm based on the information of coronal holes (CH). For this we used CH data obtained from He I $10830{\AA}$ maps at National Solar Observatory-Kitt Peak from January 1996 to November 2003 and the CIR and storm data that Choi et al. (2009) identified. Considering the relationship among coronal holes, CIRs, and geomagnetic storms (Choi et al. 2009), we propose the criteria for geoeffective coronal holes; the center of CH is located between $N40^{\circ}$ and $S40^{\circ}$ and between $E40^{\circ}$ and $W20^{\circ}$, and its area in percentage of solar hemispheric area is larger than the following areas: (1) case 1: 0.36%, (2) case 2: 0.66%, (3) case 3: 0.36% for 1996-2000, and 0.66% for 2001-2003. Then we present contingency tables between prediction and observation for three cases and their dependence on solar cycle phase. From the contingency tables, we determined several statistical parameters for forecast evaluation such as PODy (the probability of detection yes), FAR (the false alarm ratio), Bias (the ratio of "yes" predictions to "yes" observations) and CSI (critical success index). Considering the importance of PODy and CSI, we found that the best criterion is case 3; CH-CIR: PODy=0.77, FAR=0.66, Bias=2.28, CSI=0.30. CH-storm: PODy=0.81, FAR=0.84, Bias=5.00, CSI=0.16. It is also found that the parameters after the solar maximum are much better than those before the solar maximum. Our results show that the forecasting of CIR based on coronal hole information is meaningful but the forecast of goemagnetic storm is challenging.

• Korean Journal of Childcare and Education
• /
• v.8 no.2
• /
• pp.63-80
• /
• 2012

This study examined the relationship among temperament, social support and hope of institutionalized children. A total of 198 children, aged 10 to 13, recruited from 20 institutions in Seoul participated. Demographics, temperament, social support from friends, institution-family and school teacher, and hope were assessed by self-report. Results showed that in bivariate level, temperament and social support were significantly associated with level of hope. However, hierarchical multiple regressions indicated that children's hope was predicted only by age and social support from friends, institution-family and school teacher. That is, temperament was not contributed to predict hope, whilst social support contributed unique variance to the prediction of hope, controlling for age. The more social support the children felt they had, the higher levels of hope they reported. Further analyses revealed that support from friends, institution-family and school teacher were influential factors in explaining hope agency, while support from institution-family and school teacher were influential factors in explaining hope pathway of institutionalized children, controlling for age.

• Journal of Korea Water Resources Association
• /
• v.49 no.11
• /
• pp.913-922
• /
• 2016

A long-term precipitation record is typically required for establishing the reliable water resources plan in the watershed. However, the observations in the hourly precipitation data are not always consistent and there are missing values within the time series. This study aims to develop a hourly rainfall simulator for extending rainfall data, based on the well-known Neyman-Scott Rectangular Pulse Model (NSRPM). Moreover, this study further suggests a multisite hourly rainfall simulator to better reproduce areal rainfalls for the watershed. The proposed model was validated with a network of five weather stations in the Uee-stream watershed in Seoul. The proposed model appeared a reasonable result in terms of reproducing most of the statistics (i.e. mean, variance and lag-1 autocovariance) of the rainfall time series at various aggregation levels and the spatial coherence over the weather stations.

• Magazine of the Korea Concrete Institute
• /
• v.8 no.3
• /
• pp.135-146
• /
• 1996

In this study, the properties of super flowing concrete containing fly ash were experimentally investigated and compared with those of ordinary concrete. Tests were carried out on five types of super flowing concrete mixes containing fly ash and three types of ordinary concrete mixes without fly ash. Flow test, 0-funnel test, box test, L type test and slump test were carried out to obtain the properties for flowability and workability of fresh concrete. The mechanical properties of hardened concrete were also investigated in terms of compressive strength, splitting tensile strength, modulus of elasticity, creep and drying shrinkage. In fresh concrete, it was found that super flowing concrete had excellent workability and flowability compared with ordinary concrete, and had self-compactable performance. Super flowing concrete *also had good mechanical properties at both early and late ages with compressive strength reaching as high as 40 MPa at 28 days. The creep deformation of super flowing concrete investigated was relatively lower than that of ordinary concrete, but drying shrinkage was much higher.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.2
• /
• pp.15-20
• /
• 2016

The grouting method, which can be used to effectively improve small areas within a short amount of time, may have different injection effects depending on the ground conditions and the levels of a water table. In particular, for ground with a relatively large permeability, the strength of the ground and the water proof ability can decrease over time due to the leaching process. To solve this problem, a "self-healing smart grouting (SSG) method", which was designed to maintain the initial strength of the ground by minimizing the leaching process, was developed recently. In this study, uniaxial compression tests were carried out on SSG samples to understand the strength of SSG over curing time where two different curing temperatures have been applied for comparison. The uniaxial compression strength of SSG was further compared with the samples prepared using conventional methods (LW and SGR). The test results showed that the uniaxial compression strength of SSG was higher at both high and low curing temperatures compared to that of the samples prepared using conventional methods. The initial strength of SSG was also relatively higher.