• Journal of Korea Water Resources Association
• /
• v.57 no.5
• /
• pp.333-346
• /
• 2024

High-resolution medium-range streamflow prediction is crucial for sustainable water quality and aquatic ecosystem management. For reliable medium-range streamflow predictions, it is necessary to understand the characteristics of forcings and to effectively utilize weather forecast data with low spatio-temporal resolutions. In this study, we presented a comparative analysis of medium-range streamflow predictions using the distributed hydrological model, WRF-Hydro, and the numerical weather forecast Global Data Assimilation and Prediction System (GDAPS) in the Geumho River basin, Korea. Multiple forcings, ground observations (AWS&ASOS), numerical weather forecast (GDAPS), and Global Land Data Assimilation System (GLDAS), were ingested to investigate the performance of streamflow predictions with highresolution WRF-Hydro configuration. In terms of the mean areal accumulated rainfall, GDAPS was overestimated by 36% to 234%, and GLDAS reanalysis data were overestimated by 80% to 153% compared to AWS&ASOS. The performance of streamflow predictions using AWS&ASOS resulted in KGE and NSE values of 0.6 or higher at the Kangchang station. Meanwhile, GDAPS-based streamflow predictions showed high variability, with KGE values ranging from 0.871 to -0.131 depending on the rainfall events. Although the peak flow error of GDAPS was larger or similar to that of GLDAS, the peak flow timing error of GDAPS was smaller than that of GLDAS. The average timing errors of AWS&ASOS, GDAPS, and GLDAS were 3.7 hours, 8.4 hours, and 70.1 hours, respectively. Medium-range streamflow predictions using GDAPS and high-resolution WRF-Hydro may provide useful information for water resources management especially in terms of occurrence and timing of peak flow albeit high uncertainty in flood magnitude.

• Journal of Intelligence and Information Systems
• /
• v.27 no.1
• /
• pp.1-21
• /
• 2021

As the global business environment changes, uncertainties in technology development and market needs increase, and competition among companies intensifies, interests and demands for R&D activities of individual companies are increasing. In order to cope with these environmental changes, R&D companies are strengthening R&D investment as one of the means to enhance the qualitative competitiveness of R&D while paying more attention to facility investment. As a result, facilities or R&D investment elements are inevitably a burden for R&D companies to bear future uncertainties. It is true that the management strategy of increasing investment in R&D as a means of enhancing R&D capability is highly uncertain in terms of corporate performance. In this study, the structural factors that influence the R&D capabilities of companies are explored in terms of technology management capabilities, R&D capabilities, and corporate classification attributes by utilizing data mining techniques, and the characteristics these individual factors present according to the level of R&D capabilities are analyzed. This study also showed cluster analysis and experimental results based on evidence data for all domestic R&D companies, and is expected to provide important implications for corporate management strategies to enhance R&D capabilities of individual companies. For each of the three viewpoints, detailed evaluation indexes were composed of 7, 2, and 4, respectively, to quantitatively measure individual levels in the corresponding area. In the case of technology management capability and R&D capability, the sub-item evaluation indexes that are being used by current domestic technology evaluation agencies were referenced, and the final detailed evaluation index was newly constructed in consideration of whether data could be obtained quantitatively. In the case of corporate classification attributes, the most basic corporate classification profile information is considered. In particular, in order to grasp the homogeneity of the R&D competency level, a comprehensive score for each company was given using detailed evaluation indicators of technology management capability and R&D capability, and the competency level was classified into five grades and compared with the cluster analysis results. In order to give the meaning according to the comparative evaluation between the analyzed cluster and the competency level grade, the clusters with high and low trends in R&D competency level were searched for each cluster. Afterwards, characteristics according to detailed evaluation indicators were analyzed in the cluster. Through this method of conducting research, two groups with high R&D competency and one with low level of R&D competency were analyzed, and the remaining two clusters were similar with almost high incidence. As a result, in this study, individual characteristics according to detailed evaluation indexes were analyzed for two clusters with high competency level and one cluster with low competency level. The implications of the results of this study are that the faster the replacement cycle of professional managers who can effectively respond to changes in technology and market demand, the more likely they will contribute to enhancing R&D capabilities. In the case of a private company, it is necessary to increase the intensity of input of R&D capabilities by enhancing the sense of belonging of R&D personnel to the company through conversion to a corporate company, and to provide the accuracy of responsibility and authority through the organization of the team unit. Since the number of technical commercialization achievements and technology certifications are occurring both in the case of contributing to capacity improvement and in case of not, it was confirmed that there is a limit in reviewing it as an important factor for enhancing R&D capacity from the perspective of management. Lastly, the experience of utility model filing was identified as a factor that has an important influence on R&D capability, and it was confirmed the need to provide motivation to encourage utility model filings in order to enhance R&D capability. As such, the results of this study are expected to provide important implications for corporate management strategies to enhance individual companies' R&D capabilities.

• The Korean Journal of Air & Space Law and Policy
• /
• v.30 no.2
• /
• pp.403-425
• /
• 2015

The Chicago Convention and Annexes have become the basis of aviation safety regulations for every contracting state. Generally, the State's aviation safety regulations refer to the Standards and Recommended Practices(SARPs) provided in the Annexes of the Chicago Convention. In order to properly reflect international aviation safety regulations, constant studies of the aviation fields are of paramount importance. This Paper is intended to identify the main differences between korean and foreign regulation and suggest a few amendment proposals on Mixed-fleet Flying(at or more two aircraft type operation) of flight crew. Comparing with these regulations, the korean regulations and implementations have some insufficiency points. I suggest some amendment proposals of korean regulations concerning Mixed-fleet Flying that flight crew operate aircraft of different types. Basically an operator shall not assign a pilot-in-command or a co-pilot to operate at the flight controls of a type of airplane during take-off and landing unless that pilot has operated the flight controls during at least three take-offs and landings within the preceding 90 days on the same type of airplane or in a flight simulator. Also, flight crew members are familiarized with the significant differences in equipment and/or procedures between concurrently operated types. An operator shall ensure that piloting technique and the ability to execute emergency procedures is checked in such a way as to demonstrate the pilot's competence on each type or variant of a type of airplane. Proficiency check shall be performed periodically. When an operator schedules flight crew on different types of airplanes with similar characteristics in terms of operating procedures, systems and handling, the State shall decide the requirements for each type of airplane can be combined. In conclusion, it is necessary for flight crew members to remain concurrently qualified to operate multiple types. The operator shall have a program to include, as a minimum, required differences training between types and qualification to maintain currency on each type. If the Operator utilizes flight crew members to concurrently operate aircraft of different types, the operator shall have qualification processes approved or accepted by the State. If applicable, the qualification curriculum as defined in the operator's Advanced Qualification Program could be applied. Flight crew members are familiarized with the significant differences in equipment and/or procedures between concurrently operated types. The difference among different types of airpcrafts decrease and standards for these airpcrafts can be applied increasingly because function and performance have been improved by aircraft manufacture company in accordance to basic aircraft system in terms of developing new aircrafts for flight standard procedure and safety of flight. Also, it becomes more necessary for flight crews to control multi aircraft types due to various aviation business and activation of leisure business. Nevertheless, in terms of flight crew training and qualification program, there are no regulations in Korea to be applied to new aircraft types differently in accordance with different levels. In addition, it has no choice different programs based on different levels because there are not provisions to restrict or limit and specific standards to operate at or more than two aircraft types for flight safety. Therefore the aviation authority introduce Flight Standardization and/or Operational Evaluation Board in order to analysis differences among aircraft types. In addition to that, the aviation authority should also improve standard flight evaluation and qualification system among different aircraft types for flight crews to apply reasonable training and qualification efficiently. For all the issue mentioned above, I have studied the ICAO SARPs and some state's regulation concerning operating aircraft of different types(Mixed-fleet flying), and suggested some proposals on the different aircraft type operation as an example of comprehensive problem solving. I hope that this paper is 1) to help understanding about the international issue, 2) to help the improvement of korean aviation regulations, 3) to help compliance with international standards and to contribute to the promotion of aviation safety, in addition.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.17 no.3
• /
• pp.188-201
• /
• 2005

This is the first part of a two-part paper which describes comparison of reliability design methods by application to Donghae Harbor Breakwaters. This paper, Part 1, is restricted to stability of armor blocks, while Part 2 deals with sliding of caissons. Reliability design methods have been developed fur breakwater designs since the mid-1980s. The reliability design method is classified into three categories depending on the level of probabilistic concepts being employed. In the Level 1 method, partial safety factors are used, which are predetermined depending on the allowable probability of failure. In the Level 2 method, the probability of failure is evaluated with the reliability index, which is calculated using the means and standard deviations of the load and resistance. The load and resistance are assumed to distribute normally. In the Level 3 method, the cumulative quantity of failure (e.g. cumulative damage of armor blocks) during the lifetime of the breakwater is calculated without assumptions of normal distribution of load and resistance. Each method calculates different design parameters, but they can be expressed in terms of probability of failure so that tile difference can be compared among the different methods. In this study, we applied the reliability design methods to the stability of armor blocks of the breakwaters of Donghae Harbor, which was constructed by traditional deterministic design methods to be damaged in 1987. Analyses are made for the breakwaters before the damage and after reinforcement. The probability of failure before the damage is much higher than the target probability of failure while that for the reinforced breakwater is much lower than the target value, indicating that the breakwaters before damage and after reinforcement were under- and over-designed, respectively. On the other hand, the results of the different reliability design methods were in fairly good agreement, confirming that there is not much difference among different methods.

• The Journal of Korean society of community based occupational therapy
• /
• v.7 no.3
• /
• pp.23-34
• /
• 2017

Objective : The purpose of this study was to investigate establishment status of the mandatory courses designated by Ministry of Health & Welfare for qualification of sensory developmental rehabilitation specialist(SDRS), within curriculum of baccalaureate occupational therapy(BOT) programs in Korea Methods : This is a narrative study to investigate and analyze certain courses established in curriculums of all 4-years occupational therapy(OT) programs, which is 32 schools. Results : 1) The shared mandatory subject, 'Understanding Children with Disabilities(UDC)', has been established at 9 schools. For the branch mandatory subjects, 'Neuroscience(NS) or Neuroanatomy' has been established at all 32 schools, 'Sensory Processing Dysfunctions and Intervention(SPDI)' or 'Sensory Integration' has been established at 31 schools, and each of 'Assessment & Evaluation for Children(AEC)' and 'Practicum of Sensory Rehabilitation(PSR)' has been established 7 schools for same. 2) For the mandatory courses, all 32 schools were offering designated- and alternative courses of NS, SPDI, AEC, but there was no change in the number of schools offering the practicum course since there was no case of alterative for it. 3) In terms of general provision score, there were 4 schools for score 7, 4 schools for score 6, 2 schools for score 5, 1 schools for score 4, 2 schools for score 3, and 19 schools for score 2. Conclusion : Establishment of the mandatory courses required to the qualification of SDRS among the BOT programs in nation were investigated. Including alternative courses, all the branch mandatory courses except practicum course are established in all the 32 schools. However, the shared mandatory subject, UDC and the practicum subject were established in only few schools. In the provision level evaluation of BOT programs for the SDRS qualification, it is shown that many schools has been started the provision already but still many schools' curriculum did not reflect the willingness and accuracy well. For the schools planning successful accreditation in near future, it is recommended that they prioritize the establishment of the shared mandatory course and the practicum course since these two subjects are recognized as critical factors for that. In addition, it is also needed of comparative inspections for course title and syllabi based on the guideline provided by Ministry of Health & Welfare.

• The korean journal of orthodontics
• /
• v.34 no.4 s.105
• /
• pp.363-370
• /
• 2004

Patients with fixed orthodontic appliances frequently have increased levels of plaque accumulation leading to the possibility of gingivitis or enamel decalcification. Although many methods may be helpful in reducing dental plaque formation, the optimal mechanical removal of plaque is the most important factor during orthodontic treatment. The purpose of this study was to evaluate the efficacy of an electric toothbrush (with a specially designed orthodontic brush head) compared to a manual toothbrush in controlling plaque and gingivitis for patients with fixed orthodontic appliances. Oral hygiene status was measured in thirty-four patients using a plaque index, a gingival index and a bleeding index, before and four weeks after the attachment of fixed orthodontic appliances. Patients were randomly divided into two groups: electric and manual toothbrush groups. Oral hygiene instruction was given according to the type of toothbrush used. The Braun Oral-B D9511 with Braun Oral-B Ortho OD 15-1 brush head was used as the electric toothbrush while the Butler G.U.M. 124 was given as the manual toothbrush. After four md eight weeks, oral hygiene status was measured again. Through a comparison between the electric and the manual toothbrush groups, the following results were obtained. 1. All oral hygiene indices showed an increasing tendency after four weeks of fixed orthodontic appliance. 2. All indices presented a decreasing tendency four and eight weeks after oral hygiene instruction. 3. In case of the gingival index and bleeding index, the decreasing tendency did not show a statistically significant difference between the electric and the manual toothbrush groups. 4. The decreasing tendency of plaque index presented a statistically significant difference between the two groups, showing that the electric toothbrush was more effective in terms of oral hygiene. These findings suggest that an electric toothbrush is useful to orthodontic patients with fixed appliances.

• CRM연구
• /
• v.3 no.2
• /
• pp.21-41
• /
• 2010

The current research was conducted to examine the factors that affect outsourcing performances, and further investigate whether a discrepancy in performance exists between the medical institutions and hotel service institutions. The study surveyed both medical and hotel administrators for approximately two months, who managed outsourcing tasks. Total of 325 responses out of 350 distributed were collected. However, due to inadequate responses, six responses were excluded, amounting to total of 319 (155 medical institutions, 164 hotels) valid responses included in the final analysis. First, the informal outsourcing relationships between representatives of outsourcing service seekers and providers did not appear to have significant effects in terms of the levels of trust in neither medical institutions nor hotel industries. However, the relationships affected outsourcing degrees exclusively in medical institutions, showing the disparity between the two service institutions. This was explained due to the continuing long term efforts required to establish an informal relationship in medical institutions. Second, communication was shown to have positive effects on levels of trust in both medical institutions and hotel industries. This indicates a prominent outsourcing trait that emphasizes the significance of mutual cordial communication that contributes to establishing positive relationships. Third, opportunistic behavior of the outsourcing service providers appeared to negatively affect the levels of trust as well as outsourcing degrees for both medical and hotel industries. Therefore, opportunistic behaviors were found to have more tendencies to causing tension and discomfort rather than creating a relationship based on mutual credibility or conviviality. Fourth, the effect of service infrastructures on the level of trust did not appear to be significant on medical institutions, while showing positive influence on hotel industries. Additionally, service infrastructures were found to positively influence the outsourcing performance levels for both sectors. Fifth, trust between outsourcing service seekers and providers did not appear to have noticeable impact on the outsourcing degrees for either institution. On the contrary, trust appeared to have positive impacts on performance for both institutions. This further indicates that, when engaging in outsourcing, strengthening relationships through mutual partnership with outsourcing entities rather than establishing contractual relationships leads to improving the reciprocal trust, which in turn improves work results. Lastly the outsourcing degree of service seekers appeared to have positive impact on the outsourcing performance for both medical institutions and hotel industries, indicating the causal relationship between the affectability of outsourcing degrees and the following performance results.

• The korean journal of orthodontics
• /
• v.36 no.2 s.115
• /
• pp.145-152
• /
• 2006

The purpose of this study was to evaluate electroless plating as a method of increasing the diameter of an orthodontic wire in comparison with eletroplating. After pretreatment plating of the 0.016 inch stainless steel orthodontic wire, electroless plating was performed at $90^{\circ}C$ until the diameter of the wire was increased to 0.018 inch. During the process of electroless plating, the diameter of the wire was measured every 5 minutes to examine the increasing ratio of the wire's diameter per time unit. And to examine the uniformity, the diameter at 3 points on the electroless-plated orthodontic wire was measured. An X-ray diffraction test for analyzing the nature of the plated metal and a 3-point bending test for analyzing the physical property were performed. The electroless-plated wire group showed a increased tendency for stiffness, yield strength, and ultimate strength than the electroplated wire group. And there was a statistically significant difference between the two groups for stiffness and ultimate strength. In the electroless-plated wire group, the increasing ratio of the diameter was $0.00461{\pm}0.00003mm/5min$ (0.00092 mm/min). In the electroplated wire group, it was $0.00821{\pm}0.00015mm/min$. The results of the uniformity test showed a tendency for uniformity in both the plating methods. The results of this study suggest that electroless plating of the wire is closer to the ready-made wire than electroplating wire in terms of the physical property. However, the length of plating time needs further consideration for the clinical application of electroless plating.

• Korean Journal of Environmental Biology
• /
• v.28 no.4
• /
• pp.179-187
• /
• 2010

The Theory of Island Biogeography describes that the number of species on an island affected by island area and distance from the mainland. This study was performed to compare and analyze the community structure of the macro-invertebrates in three isolated islands, around Korean waters in terms of the Theory of Island Biogeography. Macrobenthic animals were collected using a modified underwater quadrat in August 2009. A total of 104 macrobenthic species were sampled with a mean density of 399 individuals $m^{-2}$ and biomass of 1,506.70 g $m^{-2}$. Based on the abundance and biomass data, there were 10 dominant species accounting for approximately 67.17% of total individuals. The highest densities were found in the amphipoda Amphipoda spp., the bivalvia Modiolus agripetus and Mytilus coruscus, the Sipunculida Phascolosoma scolops and the polychaeta Syllidae unid.. On the contrary, the top ten species made up 95.66% of the total biomass while the three most abundant, the bivalves M. coruscus, Streostria circumpicta and M. agripetus. The conventional multi-variate statistics (cluster analysis and non-metric multi-dimensional scaling) applied to assess spatial variation in macrobenthic assemblages. Cluster analysis and nMDS ordination analysis based on the Bray-Curtis similarity identified 2 station groups. The group 1 was consisted with Gageodo (except for lower station at Transect 2) and Dokdo station and was numerically dominated by the polychaetes Eunice antennata and Syllidae unid., the cirripedia Megabalanus rosa and the bivalvia M. coruscus. However, group 2 was associated with Sohwado station and was characterized by high abundance of the anomura Petrolisthes japonicus, the gastropoda Lirularia pygmaea and the brachiopoda Coptothyris grayi. In conclusion, these results suggested that the species diversity and community structure of macrobenthos in three isolated island seemed slightly related to island area and distance from the mainland.

• 대한공업교육학회지
• /
• v.37 no.1
• /
• pp.87-106
• /
• 2012

The purpose of this research is to provide basic materials in developing an efficient career guidance method of Vocational High Schools on the basis of analyzing awareness differences in students, teachers and between students and teachers as well as awareness differences according to a position of teachers in terms of the actual condition of career guidance and improvements with the target of students and teachers at Vocational High Schools. The survey was carried out by targeting students and teachers at Vocational High Schools in the Seoul Metropolis. The results of this research are as follows. First, it appeared that the awareness of students on the career guidance level of Vocational High Schools is insufficient, and students answered that employment guidance is more insufficient compared to educational guidance. In addition, the awareness of students on the career guidance conditions appeared to be generally insufficient. Second, in case of awareness of teachers on the career guidance conditions of Vocational High Schools, teachers answered that arrangement of teachers in full charge of career guidance, career counselling room, securing and utilization of latest career information and information search systems capable of using the internet for career guidance are sufficient, whereas they answered that time for career guidance, operating budget of a career counselling room and linkage with external institutions are insufficient. Third, they answered that career guidance conditions are generally sufficient in the order of a principal, vice-principal and teachers. The principal is cognizing that career guidance conditions are sufficient all question items, and the vice-principal answered that career guidance conditions are insufficient in only operating budget of a career counselling room and linkage with external institutions. Teachers answered that career guidance conditions are insufficient in only time for career guidance, operating budget of a career counselling room and linkage with external institutions. In addition, compared to teachers, the principal was cognizing that career guidance conditions are sufficient except operating budget of the career counselling room through analysis of awareness difference among principle, vice-principle and teachers. Fourth, students answered that career guidance conditions are insufficient in all question items, but teachers cognized that career guidance conditions are sufficient in all question items excluding time for career guidance. Among them, what showed a difference of the biggest awareness was analyzed as information search systems capable of using the Internet.