• Economic and Environmental Geology
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• v.47 no.6
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• pp.589-599
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• 2014

This study selected optimal sites in Myeongsasimni located in west coast of Korea for stratigraphic research containing extreme climate event during quaternary period by spatio-temporal analyses of changes in sedimentary environment and land use employing 1918 topographic map, 2000 digital terrain map, 1976 and 2012 air photographies. The study area shows no significant changes in topographic characteristics that hilly areas with relatively large variations in elevation are distributed over north and south part of the study area, and sand dues are developed along the coast line. Moreover, flat low lying areas are located at the back side of the sand dues. The movement of surface run off and sediment loads shows two major trends of inland direction flow from back sides of sand dunes and outland direction flow from high terrains inland, and the two flows merge into the stream located in the center of the study area. Two sink with individual area of $0.2km^2$ are observed in Yongjeong-ri and Jaryong-ri which are located in south central part and south part of the study area, respectively. In addition, sea level change simulation reveals that $3.4km^2$ and $3.64km^2$ are inundated with 3 m of sea level rise in 1918 and 2000, respectively, and it would contribute to chase sea level change records preserved in stratigraphy. The inundated areas overlaps well with sink areas where it indicates the low lying areas located in south cental and south part of the study area are identical for sediment accumulation. The areas with minimal human impact on sediment records over last 100 years are $3.51km^2$ distributed over central and south part of the study area with the land use changes of mud and rice field in 1918 to rice field in 2012. The candidate sites of $0.15km^2$ in central part and $0.09km^2$ in south part are identified for preferable locations of geologic record of extreme climate events during quaternary period based on the overlay analysis of optimal sedimentary environment and land use changes.

• Smart Structures and Systems
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• v.22 no.3
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• pp.341-358
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• 2018

This present study investigates Love-type wave propagation in composite structure consists of a loosely bonded functionally graded piezoelectric material (FGPM) stratum lying over a functionally graded initially-stressed fibre-reinforced material (FGIFM) substrate. The closed-form expressions of the dispersion relation have been obtained analytically for both the cases of electrically open and electrically short conditions. Some special cases of the problem have also been studied and the obtained results are found in well-agreement with the classical Love wave equation. The emphatic influence of wave number, bonding parameter associated with bonding of stratum with substrate of the composite structure, piezoelectric coefficient as well as dielectric constant of the piezoelectric stratum, horizontal initial stresses, and functional gradedness of the composite structure on the phase velocity of Love-type wave has been reported and illustrated through numerical computation along with graphical demonstration in both the cases of electrically open and electrically short condition for the reinforced and reinforced-free composite structure. Comparative study has been carried out to analyze the distinct cases associated with functional gradedness of the composite structure and also various cases which reveals the influence of piezoelectricity, reinforcement and horizontal initial stress acting in the composite structure, and bonding of the stratum and substrate of the composite structure in context of the present problem which serves as one of the major highlights of the study.

• Nuclear Engineering and Technology
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• v.7 no.4
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• pp.267-275
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• 1975

The low-lying resolved resonance structure of U-233 is investigated in terms of the Adler-Adler multilevel formalism. The resonance capture and fission cross sections of U-233 below 60 eV are calculated using Adlers' effective resonance parameters. The infinite dilution resonance integrals of U-233 are computed with the use of the Alders' parameters adjusted to fit the cross section data. It is found that the agreement of calculations with experiments is generally good over most of the energy region covered. A transformation of the Adlers' multilevel parameters into an equivalent set of the single level pseudoparameters is made for the use of the existing computer codes which are useful in the reactor calculations but do not have capability to use the multilevel parameters. The results of this transformation are presented in the form of a table.

• Bulletin of the Society of Naval Architects of Korea
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• v.2 no.1
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• pp.9-14
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• 1965

Ship designers make every efforts to get faster ships in accordance with the development of the Naval Architecture. But for the speed lying over factor length ratio 2.5-3.0, we could put a powerful engine into the conventional round bottom displacement type vessels, but it is very difficult in view point of economy, weight and volume. The principal cause of these speed obstacles is the wave making resistance and researchers are trying to decrease this resistance. One of the resolving ways, planing hulls were applied to small high boats. Planing hull's advantage is not restricted to speed, but the workmanship of the planing hull is easier than those of displacement type vessels of round bottom. Planing hull, therefore, are widely applicable to the intermediate speed boats, which don't have enough high speed to take planing advantage, as well as high speed boats. We will discuss related phenomena of the planing hull in details and this paper we particularly interested in the interjection point(speed length ratio 3.0-3.5 by Mr. D. De Groots) between semi-planing and full planing hulls on the resistance characteristic curve. The paper by Prof. Keuck Chun Kim, "Some Characteristics of Straight Framed V-bottom Hull Forms", Journal of the society of Naval Architects of Korea, Vol.1, No.1, Dec.5, 1964, is referred to the V-bottom hull forms belonging to low speed region and determines practical applicable limit of the speed length ratio combined with construction costs, under which are still used by large commercial vessels. This is the interesting contrast between his and authors. We will further discuss the speed length ratio which is considered as a beginning point to planing effect. For this analysis, we choose 3 model ships: Model (1) and (2) have the same principal dimensions, model 3 varied dimension. Model (1) is full-planing hull, (2) is semi-planing hull and (3) is complete planing hull. They are aimed to collect proper design data for purposed ships.

• Archives of design research
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• v.12 no.4
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• pp.119-128
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• 1999

Product opportunity analysis in product planning is to analyze the feasibility for success over the detail product concept, and to grasp the new possible market based on exploring the trends of market and product itself. Therefore, the correct analysis and insight with various data of product and market is needed for product opportunity analysis. As product environment changes rapidly, it is especially important to collect more plentiful informations, and to put these information to practical use pertinently. It is consequently indispensible to clarify the types of information to be needed and to construct product database. However, there has no meaning to gather simple information which is lying here and there. Product database has to be systematically organized and each product information is to be transformed into contextual one. This study clarifies a conceptual framework of product design database based on product attributes and develops prototype of product database for product planning. Case study of camera is exemplified for analyzing the product trends and exploring product opportunity with developed product database.

• Journal of the Korean Society of School Health
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• v.24 no.1
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• pp.99-109
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• 2011

Purpose: The purpose of this study was to investigate factors influencing dysmenorrhea in middle school girls and to analyze the differences in dysmenorrhea according to personal factors of the subjects. Methods: This study was conducted from March 22 to April 2, 2010. The subjects of the study were 572 girls who attended three middle schools in Seoul and experienced dysmenorrheal. All were surveyed using the same questionnaire. Data were analyzed by the SPSS/WIN 12.0 program and included descriptive statistics, ANOVA and multiple regression analysis. Results: 1) The mean age of the subjects was 13.53 years, and the mean age of first menstruation (menarche) was 11.94 years. The number of days between the onset of menstrual cycles was 30.01 days. Most of the respondents had irregular menstrual cycles and menstrual periods lasting 3 to 7 days long. 2) Chief menstrual pains were lower abdominal and back pain. Subjects reported experiencing severe lower abdominal and/or back pain, most commonly on the second day of menstruation. The average score of menstrual discomfort was over 60 points (63%). The average score per 6 points of dysmenorrhea was as follows: fatigue (3.48), sensitivity (3.27), disability of movement (3.27), napping or lying down (2.98), mood swings (2.95), interference with studies (2.87). 3) Individual subject characteristics influencing the onset of dysmenorrhea were as follows: high stress levels, being in poor health, having an irregular diet, being younger and having longer menstrual periods than most other subjects. Conclusion: During puberty, girls with earlier menarche complained of physical and emotional discomfort, and irregular menstrual periods. Therefore, we need to explain overall menstrual characteristics and individual differences in the occurrence of dysmenorrhea, in health education programs.

• PNF and Movement
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• v.13 no.2
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• pp.103-109
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• 2015

Purpose: Abdominal breathing exercises are recommended to activate the breathing muscles and the pelvic floor muscles, as well as to increase postural alignment during exhalation. The purpose of this study was to clarify the effect of improving abdominal muscle strength on menstrual pain in women in their twenties using abdominal breathing exercises. Method: In this study, 32 female university students were included as the subjects. The subjects were divided into two groups based on the area of menstrual pain: lumbar pain (n=16) and lower abdomen pain (n=16). The abdominal breathing positions were divided into two positions, which included a hook lying position and hip and knee flexions at $90^{\circ}$ in the supine position. Exercises were used to strengthen the abdominal muscles during exhalation. Four sets of the exercises were completed three times a week over the course of eight weeks. The degree of pain was measured using the Numeric Rating Scale (NRS). Muscle thickness was measured using an ultrasound. Result: The thickness of the transverse abdominis (TrA) and internal oblique (IO) increased in the lower abdomen pain group. However, thickness of the external oblique (EO) did not increased following abdominal breathing. No significant difference in posture was identified in the lower abdomen group. TrA thickness increased significantly in the lumbar pain group. However, thickness did not increase significantly in the lumbar pain group. In addition, the lumbar pain group experienced no significant effects on posture. IO thickness increased following hip and knee flexions at $90^{\circ}$ in the lumbar pain group. Menstrual pain decreased following intervention in both groups. There was no significant difference in the degree of pain reduction between both groups. Conclusion: As examples of alternative medicine, abdominal breathing exercises may be effective in decreasing menstrual pain.

• Journal of Korea Water Resources Association
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• v.52 no.3
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• pp.173-185
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• 2019

The Korean Peninsula is considered as one of the most typhoon related disaster prone areas. In particular, the potential risk of flooding in coastal areas would be greater when storm surge and heavy rainfall occurred at the same time. In this context, understanding the mechanism of the interactions between them and estimating the risk associated with the concurrent occurrence are of particular interests especially in low-lying coastal areas. In this study, we developed a Poisson-Generalized Pareto (Poisson-GP) distribution based storm surge frequency analysis model to combine the occurrence of the exceedance of a threshold, that is the peaks over threshold (POT), within a Bayesian framework. The storm surge frequency analysis technique developed through this study might contribute to the improvement of disaster prevention technology related to storm surge in the coastal area.

• Journal of Animal Science and Technology
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• v.64 no.6
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• pp.1237-1244
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• 2022

Horse breeders suffer massive economic losses due to dystocia, abortion, and stillbirths. In Thoroughbred mares, breeders often miss the foaling process because approximately 86% of the foaling events occur from 19:00 to 7:00; consequently, breeders cannot assist mares experiencing dystocia. To solve this problem, various foaling alarm systems have been developed. However, there is a need to develop a new system to overcome the shortcomings of the existing devices and improve their accuracy. To this end, the present study aimed to (1) develop a novel foaling alarm system and (2) compare its accuracy with that of the existing Foalert^TM system. Specifically, eighteen Thoroughbred mares (11.9 ± 4.0 years old) were included. An accelerometer was used to analyze specific foaling behaviors. Behavioral data were transmitted to a data server every second. Depending on the acceleration value, behaviors were automatically classified by the server as categorized behaviors 1 (behaviors without change in body rotation), 2 (behaviors with sudden change in body rotation, such as rolling over), and 3 (behaviors with long-term change in body rotation, such as lying down laterally). The system was designed to alarm when the duration of categorized behaviors 2 and 3 was 12.9% and that of categorized behavior 3 was 1% during 10 min. The system measured the duration of each categorized behavior every 10 min and transmitted an alarm to the breeders when foaling was detected. To confirm its accuracy, the foaling detection time of the novel system was compared with that of Foalert^TM. The novel foaling alarm system and Foalert^TM alarmed foaling onset respectively 32.6 ± 17.9 and 8.6 ± 1.0 min prior to foal discharge, and the foaling detection rate of both systems was 94.4%. Therefore, the novel foaling alarm system equipped with an accelerometer can precisely detect and alert foaling onset.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2000.05a
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• pp.1-1
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• 2000

The results of the modification of metal materials treated by high temperature pulst:d plasma fluxes (HTlPPF) with a specific power of incident flux changing in the $(3...100)10^5{]\;}W/cm^2$ range and a pulse duration lying from 15 to $50{\;}\mu\textrm{s}$ have been presented. The results of HTPPF action were studied on the stainless steels of 18Cr-l0Ni, 16Cr- 15Ni, 13Cr-2Mo types; on the structural carbon steels of (13...35)Cr, St. 3, St. 20, St. 45 types; on the tool steels of U8, 65G, ShHI5 types, and others; on nickel and high nickel alloy of 20Cr-45Ni type; on zirconium- and vanadium-base alloys and other materials. The microstructure and properties (mechanical, tribological, erosion, and other properties) of modified materials and surface alloying of metals exposed to HTPPF action have been investigated. It was found that the modification of materials by HTPPF resulted in a simultaneous increase of several properties of the treated articles: microhardness of the surface and layers of 40...60 $\mu\textrm{m}$ in depth, tribological characteristics (friction coefficient, wear resistance), mechanical properties ({\sigma_y}, {\;}{\sigma_{0.2}}.{\;}{\sigma_r}) on retention of the initial plasticity ($\delta$), corrosion resistance, radistanation erosion under ion irradiation, and others. The determining factor of the changes observed is the structural-phase modification of the near-surface layers, in particular, the formation of the fine cellular structure in the near-surface layers at a depth of $20{\;}{\mu\textrm{m}}$ with dimension of cells changing in the range from 0.1 to $1., 5{\;}\mu\textrm{m}$, depending on the kind of material, its preliminary treatment, and the parameters of plasma fluxes. The remits obtained have shown the possibility of purposeful surface alloying of metals exposed to HTPPF action over a depth up to 20...45 $\mu\textrm{m}$ and the concentration of alloying element (Ni, Cr, V) up to 20 wt.%. Possible industrial brunches for using the treatment have been also considered, as well as some results on modifying the serial industrial articles by HTPPF.