• Korean Journal of Remote Sensing
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• v.26 no.4
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• pp.421-437
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• 2010

Surface particulate organic carbon (POC) concentration estimated from Maximum Normalized Difference Carbon Index (MNDCI) algorithm using SeaWiFS data is used to determine spatial and temporal variations of the Changjiang Diluted Water (CDW) in the East China Sea. 10-year monthly POC concentrations (1997-2007) show clearly seasonal variations. Inter-annual variation of POC in whole and three different areas separated by standard deviation is not linearly correlated with the Changjiang River discharge that has decreased after 1998. To determine more detailed spatial and temporal POC variations, we used empirical orthogonal function (EOF) analysis in summer (Jun.-Sep.) from 2000 to 2007. First mode is spatially and temporally correlated with the area influenced by the Changjiang River discharge. Second mode is temporally less sensitive with the Changjiang River discharge but spatially correlated with north-south patterns. Relatively higher POC variations during 2000 and 2003 were shown in the southern East China Sea. These patterns during 2004 and 2007 moved to the northern East China Sea. This phenomenon is better related to spatial variations of wind-direction than the amount of Changjiang River discharge, which is verified from in-situ measurement.

• Korean Journal of Remote Sensing
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• v.14 no.1
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• pp.37-52
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• 1998

The NSCAT(NASA Scatterometer) carried by the japanese Advanced Earth Observing Satellite(ADEOS) was the first high resolution(25 km) device for the direct wind measurement over the ocean. Even it was ceased to operate in lune of 1977 because of the power failure, it gave the first opportunity to the marine meteorologists to study the direct measured ocean wind during its 9 months of operation, especially around Korea. This study is to show monthly mean ocean wind and wind stress curl fields around Korea from January, 1997 to June, 1997. Mean ocean winds in January are predominantly northwesterly and the strongest wind(12 m/s) is found near Vladivostok. The winds in the western East Sea are strongly inf1uenced by the mountain range in Korea and these topographically influenced winds make about five times larger wind stress curl fields than previous estimates based on the weather maps. The calculation of Sverdrup transport in the East Sea shows the possibility of the directional change of the East Korean Cold Current from southward to northward direction caused by the winter wind. The downwelling area near North Korea has maximum estimated speed of 45 m in january and this wind induced downwelling makes good condition for the formation of Intermediate East Sea Water together with vigorous mixing by the strong wind.

• Korean Journal of Remote Sensing
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• v.16 no.3
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• pp.221-233
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• 2000

An intertidal topography is continuously changed due to morphodynamics processes. Detection and measurement of topographic change for a tidal flat is important to make an integrated coastal area management plan as well as to carry out sedimentologic study. The objective of this study is to generate intertidal DEM using leveling data and waterlines extracted from optical and microwave remotely sensed data in a relatively short period. Waterline is defined as the border line between exposed tidal flat and water body. The contour of the terrain height in tidal flat is equivalent to the waterline. One can utilize satellite images to generate intertidal DEM over large areas. Extraction of the waterline in a SAR image is a difficult task to perform partly because of the presence of speckle and partly because of similarity between the signal returned from the sea surface and that from the exposed tidal flat surface or land. Waterlines in SAR intensity and coherence map can effectively be extracted with MSP-RoA edge detector. From multiple images obtained over a range of tide elevation, it is possible to build up a set of heighted waterline within intertidal zone, and then a gridded DEM can be interpolated. We have tested the proposed method over the Gomso Bay, and succeeded in generating intertidal DEM with relatively high accuracy.

• Journal of the Korean Society of Child Welfare
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• no.32
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• pp.129-160
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• 2010

This paper provides a review of research in the area of child(hood) sexual abuse. Particularly, the paper focuses on understanding the direction of research trends in Korea on this topic by evaluating the methodological changes, diversity of topics, and factors associated with research participants. The systemic, comprehensive review includes 28 articles in 14 primary Korean Journals and 261 articles in "Child Abuse and Neglect" and "Child Maltreatment" published from 2000 to 2008. Foci of the reviewing process were; (1) Do the transition of research methods follow scientific saturation? (2) What are the main subject areas of the field? (3)Who are the research participants and from where were they recruited? The review finds that overall, the number of CSA studies fluctuated in early 2000, but remained stable which means that academic interests have remained along with the social concern. The Korean CSA studies are imbalanced in terms of scientific saturation. Studies with theoretical methods are short in numbers, but there is a rapidly growing number of research using qualitative approaches. The review also highlights that most quantitative research utilized cross-sectional survey methodology. The major research themes that were most frequently found were studies on factors associated with CSA and evaluation of treatment modalities. However, research on perpetrators and measurement scale development were rather rare. In the CA&N and CM articles, study participants are frequently recruited from mental health clinics or related social agencies. Korean samples usually come from schools than communities and young children and their mothers seem to be excessively represented. Balanced research efforts are strongly suggested.

• Journal of Korea Port Economic Association
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• v.30 no.1
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• pp.23-55
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• 2014

The purpose of this paper is to show the clustering trend and to choose the clustering ports for 3 Korean ports(Busan, Incheon and Gwangyang Ports) by using the self organizing maps based on neural network(SOM) and Tier models for 38 Asian ports during 11 years(2001-2011) with 4 input variables(birth length, depth, total area, and number of crane) and 1 output variable(container TEU). The main empirical results of this paper are as follows. First, clustering results by using SOM show that 3 Korean ports[Busan(26.5%), Incheon(13.05%), and Gwangyang(22.95%) each]can increase the efficiency. Second, according to Tier model, Busan(Hongkong, Sanghai, Manila, and Singapore), Incheon(Aden, Ningbo, Dabao, and Bangkog), and Gwangyang(Aden, Ningbo, Bangkog, Hipa, Dubai, and Guangzhou) should be clustered with those ports in parentheses. Third, when both SOM and Tier models are mixed, (1) efficiency improvement of Busan Port is greater than those of Incheon and Gwangyang ports. (2) Incheon port has shown the slow improvement during 2001-2007, but after 2008, improvement speed was high. (3) improvement level of Gwangyang port was high during 2001-2003, but after 2004, improvement level was constantly decreased. The policy implication of this paper is that Korean port policy planner should introduce the SOM, and Tier models with the mixed two models when clustering among the Asian ports for enhancing the efficiency of inputs and outputs.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.1
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• pp.12-17
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• 2007

This study was conducted to evaluate the characteristics of nonpoint source pollutants discharge from a small rural watershed. A typical rural area in Gongju City, Korea, was selected as the research site. Water quality and quantity in streams and rainfall samples were analyzed periodically from May to October 2005. Pollutant loads were estimated from a nonpoint source pollution model (AvSWAT, Arcview Soil and Water Assessment Tool). During the rainy season, from June 26 to 30 September 2005 and the dry season, before 26 June and after 30 September 2005, biological oxygen demands and chemical oxygen demands accounted for 91.3% and 93.7% of annual load, respectively, while total-N and total-P were 97.1% and 91.1% of annual load, respectively. The observed stream flow was $66.5m^3sec^{-1}$, while simulation stream flow was $66.2m^3sec^{-1}$. That can be assumed that simulation can be used to estimate the stream flow without practical measurement. However, the runoff trend following the occurrence of a storm event was not recorded properly.

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.789-794
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• 2021

Brachytherapy is a treatment in which radioactive isotopes are placed inside the body to intensively irradiate the tumor with radiation. Because brachytherapy uses a radioisotope source with a high dose rate, it is very important to know the exact location and dose of the source. However, in clinical practice, it is evaluated inaccurately with the naked eye through rulers and autoradiographs. Therefore, in this study, a dosimeter that can be used for brachytherapy was developed using a lead(II) iodide (PbI₂) material, and the applicability was evaluated by analyzing the reproducibility, linearity, and PID items. As a result of reproducibility evaluation, the RSD value was 1.41%, satisfying the evaluation criteria of 1.5%. As a result of the linearity evaluation, the R² value was 0.9993, which satisfies the evaluation criterion of 0.9990. As a result of PID evaluation, it showed only a difference of 0.06 cm compared with the theoretical value of the inverse square law of distance at the 50% dose reduction point. The dosimeter manufactured in this experiment shows results that satisfy the standard in all evaluations, so it is judged that the possibility of applying the dosimeter in the radiation brachytherapy area is sufficient.

• Journal of Conservation Science
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• v.37 no.5
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• pp.505-515
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• 2021

In this study, we evaluated the slope stability of the Pohang Daljeon-ri columnar joint (Natural Monuments # 415) and calculated the maximum energy, jumping height and moving distance of rockfalls using a simulation. Based on the results, we established the range of rockfall risk. The slopes of the Pohang Daljeon-ri columnar joint have dip directions of 93.79°, 131.99°, 165.54° and 259.84° from left (SW) to right (NE). Furthermore, they have a fan-like shape. The Pohang Daljeon-ri columnar joints are divided into four sections depending on the dip direction. The measurement results of the discontinuous face show that zone 1 is 125, zone 2 is 261, zone 3 is 262, zone 4 is 43. The results of slope stability analyses for each section using a stereographic projection method correspond to the range of planar and toppling failure. Although it is difficult to diagnose the type of failure, risk evaluation of currently falling rocks requires further focus. The maximum movement distance of a rockfall in the simulation was approximately 66 m and the rockfall risk range was the entire area under slope. In addition, it is difficult to forecast where a rock will fall as it rolls in various directions due to topographic factors. Thus, the installation of measures to prevent falling is suggested to secure the stability based on the results of the rockfall simulations and its probabilistic analysis.

• Journal of Internet of Things and Convergence
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• v.7 no.3
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• pp.15-22
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• 2021

The purpose of this study is to identify the factors that influence the nursing students' nurse image and professional self-concept on career exploration. This study was accomplished on 153 students in the 2nd, 3rd and 4th grades of the Department of Nursing Science at a college in area Y, and data were collected from July 1 to August 31, 2020 using a structured questionnaire. Measurement tools consisted of nurse image, professional self-concept, and career exploration behavior. Data processing was performed using the SPSS 22.0 program where general characteristics were analyzed by t-test, ANONA and post examination tests by Scheffe's test, using mean score, standard deviation, Pearson's correlation, and stepwise multiple regression. Nursing students' nurse image, professional self-concept, and career exploration behavior were all found to have significant positive correlations, and the most influential variable was professional self-concept. As for the total explanatory power of these variables, model 2 showed 25% explanatory power, which was increased by 2% compared to model 1. Based on this result, it is necessary to develop education and a career exploration action program which can improve the nurse image and professional self-concept.

• Korean Journal of Construction Engineering and Management
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• v.22 no.3
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• pp.40-51
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• 2021

MLS (Mobile Laser Scanning) which is a scanning method done by moving the LiDAR (Light Detection and Ranging) is widely employed to capture indoor PCD (Point Cloud Data) for floor plan generation in the AEC (Architecture, Engineering, and Construction) industry. The movement and rotation of LiDAR in the scanning phase cause deformation (i.e. skew) of PCD and impose a significant impact on quality of output. Thus, a de-skewing method is required to increase the accuracy of geometric representation. De-skewing methods which use position and pose information of LiDAR collected by IMU (Inertial Measurement Unit) have been mainly developed to refine the PCD. However, the existing methods have limitations on de-skewing PCD without IMU. In this study, a novel algorithm for de-skewing 2D PCD captured from MLS without IMU is presented. The algorithm de-skews PCD using scan matching between points captured from adjacent scan positions. Based on the comparison of the deskewed floor plan with the benchmark derived from TLS (Terrestrial Laser Scanning), the performance of proposed algorithm is verified by reducing the average mismatched area 49.82%. The result of this study shows that the accurate floor plan is generated by the de-skewing algorithm without IMU.