• Journal of the Korean Society for Library and Information Science
• /
• v.57 no.1
• /
• pp.93-114
• /
• 2023

Information extraction can facilitate the intensive analysis of documents by providing semantic triples which consist of named entities and their relations recognized in the texts. However, most of the research so far has been carried out separately for named entity recognition and relation extraction as individual studies, and as a result, the effective performance evaluation of the entire information extraction systems was not performed properly. This paper introduces two models of end-to-end information extraction that can extract various entity names in clinical records and their relationships in the form of semantic triples, namely pipeline and joint models and compares their performances in depth. The pipeline model consists of an entity recognition sub-system based on bidirectional GRU-CRFs and a relation extraction module using multiple encoding scheme, whereas the joint model was implemented with a single bidirectional GRU-CRFs equipped with multi-head labeling method. In the experiments using i2b2/VA 2010, the performance of the pipeline model was 5.5% (F-measure) higher. In addition, through a comparative experiment with existing state-of-the-art systems using large-scale neural language models and manually constructed features, the objective performance level of the end-to-end models implemented in this paper could be identified properly.

• Korean Journal of Social Welfare Studies
• /
• v.41 no.1
• /
• pp.119-144
• /
• 2010

This study advances the knowledge of developmental patterns in affiliation with delinquent peers and delinquency during adolescence; data were obtained from waves 1-5 (2003-2007) of the Korea Youth Panel Survey. Semi-parametric group-based modeling (SGM) identified 3 affiliative trajectories of delinquent peers from age 13 to 16: rarely or never, persistently affiliative, and declining groups; and five developmental trajectories of delinquency: non-offending, late onset, low-level continuous, desisting, and chronic groups. A joint trajectory analysis predicted the membership of delinquency trajectories conditional on delinquent peer trajectories. Persistently affiliative group was more likely than others to follow chronic trajectory of delinquency; the rarely or never affiliative group was more likely to be non-offending. This study may help reconcile different theoretical models such as influence, selection, and enhancement models with respect to the role of delinquent peers in delinquency. The distinct theoretical models are equally valid, albeit each model pertains to a specific aspect of longitudinal patterns of affiliation with delinquent peers. Implications of this study for youth welfare were discussed to reduce increased risks for both affiliation with delinquent peers and delinquency.

• International Journal of Highway Engineering
• /
• v.10 no.1
• /
• pp.1-9
• /
• 2008

Five bases for of highways are sight distance, vehicle stability, driver comfort, drainage and aesthetics. Among these bases, the sight distance is the most critical one in the highway alignment design. It is certain that highways and drivers' observation actions are 3-dimensional in nature. But, the highway alignment design and the sight distance analysis have been performed on 2-dimensional planes because of various constraints and complexity of calculating 3-dimensional sight distance. The purpose of this study is to derive a model for determining exact available sight distance in 3-D combined horizontal and vertical alignments. Application of the model is illustrated using numerical examples. The proposed model should be useful in quantifying the criteria for 3-D highway alignments.

• Journal of Digital Contents Society
• /
• v.15 no.2
• /
• pp.137-145
• /
• 2014

In this paper, we focus on end-to-end transfer delay improvement by using erasure coding when delivering expediting message consisting of M packets in networks with high coefficient of variation of transfer time. In the scheme, M packets are divided into b groups with each having g packets. Each group is erasure coded with additional r packets and transmitted. Since the first arrived g packets among g+r packets completes the delivery of the group, the delivery time of the expediting message is reduced. For the scheme, we investigate the optimum group size and number of redundancy packets considering delivery delay reduction and additional transmission cost caused by using erasure coding. From the results of the investigation, we see that the proposed scheme is effective in networks having high variability of transfer time and would be very useful and practical especially for the case that expedited deliveries of messages are needed.

• Korean Journal of Social Welfare
• /
• v.64 no.1
• /
• pp.101-124
• /
• 2012

This study examined the longitudinal changes of self-perceptions of own aging among middle-aged and elderly adults, using the latent growth modeling with the three waves of the "Aging and the Quality of Life of the Elderly in Korea", which sampled adults aged over 45 living in Seoul and Chuncheon. The dependent variable is attitudes toward own aging, the sub-scale of the Philadelphia Geriatric Center Morale Scale developed by Lawton (1975). The results showed that the research participants' attitudes of their own aging deteriorated over time. In addition, the lower initial status of the research participants' attitudes of their own aging was associated with being older, being non-married, living in rural areas, attaining the lower level of education, having the fewer social activities, reporting the worse subjective economic status, and reporting the worse subjective health status. The slope of the research participants' attitudes of their own aging differed by the residence areas, educational attainments, subjective economic status and subjective health status. In particular, the difference of the initial status by educational attainments grew over time. Social welfare policy and practice implications are discussed for middle-aged and elderly adults to improve attitudes toward their own aging.

• The KIPS Transactions:PartC
• /
• v.17C no.3
• /
• pp.299-306
• /
• 2010

IPTV and VoIP services are considered as killer applications over Mobile WiMAX network, which provideshigh mobility and data rate. Among those which affect the quality of voice in those services, the jitter buffer or playout buffer can compensate the poor voice quality caused by the packet drop due to frequent route change or differences among routes between service endpoints. In this paper, we analyze the correlation between the sleep interval length and jitter buffer size in order to guarantee a predefined level of voice quality. For this purpose, we present an end-to-end delay model considering additional delay incurred by the WiMAX PSC-II sleep mode and a VoIP service quality requirement based on the delay constraints. Through extensive simulation experiments, we also show that the increase of jitter buffer size may degrade the voice quality since it can introduce additional packet drop in the jitter buffer under WiMAX power saving mode.

• Journal of Practical Engineering Education
• /
• v.11 no.2
• /
• pp.291-303
• /
• 2019

The purpose of this research was to investigate the effect of the achievement goal orientation on college students' life satisfaction and sense of the belonging. This study used the analysis of the latent growth model to comprehend the slope of the 3 years longitudinal data. The result was that mastery approach and mastery avoidance affected the initial value of college life satisfaction, but not its slope as the time of 3 years went. On the other hand, performance approach was the opposite of mastery approach and mastery avoidance to college students' life satisfaction. Performance avoidance did not have an influence on both the initial value and the slope of college students' life satisfaction. The effect of the achievement goal orientation to the sense of belonging was also explored and its result was that mastery approach and mastery avoidance affected the initial value of the sense of belonging. However, it was different that performance approach did not influence the slope of the sense of belonging.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.3
• /
• pp.280-287
• /
• 2010

The first Korean satellite launch vehicle, KSLV-I(Korea Space Launch Vehicle-I), was launched for its first flight test on Aug. 25, 2009 from Naro Space Center located in south Jolla province. Because launch vehicles usually fly long range with large amount of propellants aboard, preparation of countermeasures against potential malfunctions during flight is essential in launch operation. In this paper, the flight safety operation, prepared to guarantee flight safety during launch operation of KSLV-I, is presented. Prior to flight test, flight safety analysis is performed to estimate associated risk levels quantitatively, and during flight, flight safety systems are operated to cope with any risky situations. Real-time flight monitoring including computation of instantaneous impact point using tracking data is executed normally and the flight test is completed without activation of flight termination system.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.49 no.11
• /
• pp.9-16
• /
• 2012

In this paper, we focus on end-to-end transfer delay improvement by using network coding and propose a scheme where a message is divided into several packets which are network coded generating additional redundancy with the results that the number of transmitted packets increases. In networks with high coefficient of variation of transfer time, increased number of packets could reduce the transfer time of the message to a destination. For the proposed scheme, we investigate the optimum number of divided packets and redundancy considering transfer delay reduction and additional transmission cost caused by using network coding under the restriction of maximum transmission packet size. From the results of the investigation, we see that the proposed scheme is effective in networks having high variability of transfer time and would be very useful and practical especially for the case that expedited deliveries of messages are needed.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.4
• /
• pp.102-109
• /
• 2006

In this paper, the system level EMC radiated emission test results of KoDSat(Korea Demonstration Satellite), its affects upon the Launch vehicle and H/W improving methods regarding its over exceed value of EMC specification are discussed. Regarding its over exceed value, we estimated that DAU of KoDSat generated the exceeded EMC noise source, and these test results were analyzed using the EMC2000 tool to find out how did it affect the FTS(Flight Termination Subsystem) of KSLV-1(Korea Small Launch Vehicle). To diminish the EMC noise source of UHF(430.1Mhz) band level, we redesigned the DAU power board to be applied the various schemes for EMI noise reduction such as grounding, shielding and EMI filtering, and also verified these reworks to analyze its diminishing affects in UHF band level by means of performing the DAU box level EMC test and performing the second KoDSat's system level EMC test.