• Journal of Positioning, Navigation, and Timing
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• v.6 no.3
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• pp.125-133
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• 2017

Time comparison is necessary for the verification and synchronization of the clock. Two-way satellite time and frequency (TWSTFT) is a method for time comparison over long distances. This method includes errors such as atmospheric effects, satellite motion, and environmental conditions. Ionospheric delay is one of the significant time comparison error in case of the carrier-phase TWSTFT (TWCP). Global Ionosphere Map (GIM) from Center for Orbit Determination in Europe (CODE) is used to compare with Bernese. Thin shell model of the ionosphere is used for the calculation of the Ionosphere Pierce Point (IPP) between stations and a GEO satellite. Korea Research Institute of Standards and Science (KRISS) and Koganei (KGNI) stations are used, and the analysis is conducted at 29 January 2017. Vertical Total Electron Content (VTEC) which is generated by Bernese at the latitude and longitude of the receiver by processing a Receiver Independent Exchange (RINEX) observation file that is generated from the receiver has demonstrated adequacy by showing similar variation trends with the CODE GIM. Bernese also has showed the capability to produce high resolution IONosphere map EXchange (IONEX) data compared to the CODE GIM. At each station IPP, VTEC difference in two stations showed absolute maximum 3.3 and 2.3 Total Electron Content Unit (TECU) in Bernese and GIM, respectively. The ionospheric delay of the TWCP has showed maximum 5.69 and 2.54 ps from Bernese and CODE GIM, respectively. Bernese could correct up to 6.29 ps in ionospheric delay rather than using CODE GIM. The peak-to-peak value of the ionospheric delay for TWCP in Bernese is about 10 ps, and this has to be eliminated to get high precision TWCP results. The $10^{-16}$ level uncertainty of atomic clock corresponds to 10 ps for 1 day averaging time, so time synchronization performance needs less than 10 ps. Current time synchronization of a satellite and ground station is about 2 ns level, but the smaller required performance, like less than 1 ns, the better. In this perspective, since the ionospheric delay could exceed over 100 ps in a long baseline different from this short baseline case, the elimination of the ionospheric delay is thought to be important for more high precision time synchronization of a satellite and ground station. This paper showed detailed method how to eliminate ionospheric delay for TWCP, and a specific case is applied by using this technique. Anyone could apply this method to establish high precision TWCP capability, and it is possible to use other software such as GIPSYOASIS and GPSTk. This TWCP could be applied in the high precision atomic clocks and used in the ground stations of the future domestic satellite navigation system.

• Journal of Korean Academy of Nursing
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• v.28 no.1
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• pp.7-16
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• 1998

Various difficulties and inconveniences arise from having a mentally handicapped child in a family and these place many demands on mothers. There are few studies in Korea on these demands nor on what mothers go through with their mentally handicapped daughters' menarche and puberty. The purpose of the study was to examine the experiences of mothers of mentally handicapped daughters, as it relates to their daughters' menarche and the beginning of puberty. With indepth interviews, both in person and by telephone and participant observation the study used a qualitative research methodology to attempt to understand the experiences of these mothers. The data were gathered from October 1995 to April 1996. The subjects for the research included nine mothers of mentally handicapped daughters whose ages ranged from 12 to 18 and who attended one of three special schools located in either Inchon or Seoul. The data were recorded and analyzed : meaningful statements were grouped according to subjects raised by the mothers. Content Analysis was also applied to identify similar content and confirm common experiences. and to highlight concepts and categorized them. The results of this study are as follows. Five categories were identified : mothers' emotional responses to their mentally handicapped daughters' menarche and menstration were of severe despair accompanied by anxiety, guilt, fear, anguish, shame and pity because the mothers were afraid their daughters would not be able to use appropriate hygienic measures during menstration and the mothers felt heavily burdened in having to look them. The mothers also had negative feelings about their daughters' physical development. The experience of mothers related to their daughters' possibilities for marriage and pregnancy were of powerlessness, distress, withdrawal, fear. pity and desperation and they were afraid that their daughters might be violated sexually. The mothers rejected the possibility of marriage and pregnancy for their daughters and instead planned very restricting futures for them. The mothers used various coping methods to bring meaning to their lives. Because the negative emotional responses of the mothers. nurses need to work to empower mothers to overcome these negative responses. Sex education can also play an important role especially for the daughters especially through the use of visual aids. Further, nurses should understand the tearing difficulties of mentally handicapped daughters, what mothers need and also what they experience with their mentally handicapped daughters. In conclusion, nurses should understand the negative experiences of the mothers in relation to their mentally handicapped daughters' menarche, help the mothers cope with the negative. emotions through real life education and counselling. In addition, there is a need for nursing interventions and an administrative system which will minimize the prejudices of society towards handicapped people.

• The Journal of the Convergence on Culture Technology
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• v.4 no.1
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• pp.193-200
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• 2018

This study is an experiential case study of cybercrime fraud that combines pharming and voice phishing in April 2017. Research on victims who have actually suffered in the study of crime or disaster is a very useful field in establishing crime prevention measures. This study is significant in that Korea is relatively poor in this kind of research. I got cyber fraud as a consequence of my loss of reasonable judgment due to mental confusion when a companion dog who was raised for 8 years was in a very dangerous situation with cystitis. Fortunately, I received all the damages in a quick report, but the period was eight months. It took too much time to get back all the damages, so I had to suffer another pain. Based on my experience, I suggest damage prevention measures. First, when a certain condition and a certain amount are transferred, the transaction is automatically stopped or a more strict confirmation procedure is added. Secondly, trafficking means to arrest the perpetrator without any harm to the victim is sought. Third, the victims of crime should be promptly reimbursed for damages or a system for lending their living funds to zero or lower interest rate.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.649-653
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• 2001

The Chiari malformation is a deformation within the central nervous system which the lower brain stem and the cerebellum migrate into the foramen magnum causing herniation. In 1891, Arnold Chiari classified such symptoms into 3 categories. This case report is of a 8-year-old female with the complaint of a slight facial swelling and pain on the upper right molar during tooth brushing since 10 days before. Clinical examination showed gingival pocket formation on distal of the upper right first molar with pain and mobility of the tooth. Radiographic examination showed generalized low bone density in the upper molar area, and especially no bone support above the upper right and left first molars were noted. With a temporary diagnosis of Early-onset periodontitis, consultations with medical doctors for the possibility of an underlying systemic disease were made during periodontal treatment. 3D CT was taken with after a final diagnosis of Chiari malformation. Generalized thinning and defect of the cranial bone was noted and the foramen magnum was slightly enlarged. The occipital and maxillary bone was low in density, and the alveolar bone of maxillary posterior teeth was especially almost non-existing causing the upper right and left first molar to be floating. For this, the patient went under consultation with the department of neurosurgery and is still under observation. Periodontitis in childreren is very rare. When symptoms of periodontitis appear in a child, due to the possibility of an underlying systemic disease such as leukemia, histiocytosis X, and hypophosphatasia, proper examinations should be carried out so that the primary factor the symptoms can be treated.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.5
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• pp.535-542
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• 2014

This research concluded that the area is most sensitively affected by the maritime traffic congestion rather than other factors including the ship's speed and fairway width. We performed a literature review for the area used in Japan, Denmark, and Shanghai ports, and analyzed by comparing with the area in Jinhae, Korea through the observation survey of marine traffic. The result of sensitivity analysis concluded that the congestion is affected by amount of 10% by changing 1 knot of the ship's speed, 18% of 100m of the fairway width, and 34%~43% of 1L of ship's length. By applying the result into the current audit system using $8L{\times}3.2L$, $6L{\times}1.6L$, we found that there is big difference with $3.5L{\times}1.5L$ in Japan, $5.9L{\times}2.2L$ in Shanghai, $4L{\times}5B$ in Denmark, and $3L{\times}2L$ in Jinhae, Korea. For this reason, further studies should be carried out in near future to the area mostly affected by congestion.

• Journal of Korea Water Resources Association
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• v.39 no.12 s.173
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• pp.1043-1056
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• 2006

Our ultimate purpose is to investigate the potential change in regional surface climate due to the global warming and to produce higher quality regional surface climate information over the Korean peninsula for comprehensive impact assessment. Toward this purpose, we carried out two 30-year long experiments, one for present day conditions (covering the period 1971-2000) and one for near future climate conditions (covering the period 2021-2050) with a regional climate model (RegCM3) using a one-way double-nested system. In order to obtain the confidence in a future climate projection, we first verify the model basic performance of how the reference simulation is realistic in comparison with a fairly dense observation network. We then examine the possible future changes in mean climate state as well as in the frequency and intensity of extreme climate events to be derived by difference between climate condition as a baseline and future simulated climate states with increased greenhouse gas. Emphasis in this study is placed on the high-resolution spatial/temporal aspects of the climate change scenarios under different climate settings over Korea generated by complex topography and coastlines that are relevant on a regional scale.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.217-223
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• 2015

We investigated the emulsifying properties of barley octenyl succinic anhydride (OSA)-${\beta}$-glucan, such as changes in the fat globule size and zeta-potential as influenced by pH or the addition of NaCl. Additional experiments to fabricate a suitable co-surfactant system were also performed. We found that the fat globule size in OSA-${\beta}$-glucan emulsions increased upon lowering the pH (i.e., under acidic conditions) or increasing the NaCl concentration. These results were confirmed through microscopic observation. Co-surfactant hydrophilic Tween 20 was found to be suitable for the OSA-${\beta}$-glucan emulsion, which facilitated the formation of smaller fat globules and enhanced the creaming stability when it was added in >0.2 wt% concentration. From the results of the surface load of OSA-${\beta}$-glucan in emulsions, Tween 20 addition enhanced the stability probably by the co-adsorption of the two surfactants at the droplet surface.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.37.2-37.2
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• 2011

Our previous study on tiny pores (R < 2") observed by HINODE/Solar Optical Telescope (SOT) revealed that the plasma in the pores at the photosphere is always moving down and the pores are surrounded by the strong downward motions (highly red-shifted) of neighboring granulations. From this study, we speculated that the flow motions above the pore should be related with the motions at the photosphere, since the pore is strong magnetic field region. Meanwhile, SNU and KASI installed Fast Imaging Solar Spectrograph (FISS) in the Cude room of the 1.6 m New Solar Telescope (NST) at Big Bear Solar Observatory. FISS is a unique system that can do imaging of H-alpha and Ca II 8542 band simultaneously, which is quite suitable for studying of dynamics of chromosphere. To get some clue on the relationship between the photospheric and low-chromospheric motions at the pore region, we took a coordinate observation with NST/FISS and Hinode/SOT for new emerging active region (AR11117) on October 26, 2010. In the observed region, we could find two tiny pores and two small magnetic islands (SMIs), which have similar magnetic flux with the pores but does not look dark. Magnetic flux density and Doppler velocities at the photosphere are estimated by applying the center-of-gravity (COG) method to the HINODE/spectropolarimeter (SP) data. The line-of-sight motions above the photosphere are determined by adopting the bisector method to the wing spectra of Ha and CaII 8542 lines. As results, we found the followings. (1) There are upflow motion on the pores and downflow motion on the SMIs. (2) Towards the CaII 8542 line center, upflow motion decrease and turn to downward motion in pores, while the speed of down flow motion increases in the SMIs. (3) There is oscillating motion above pores and the SMIs, and this motion keep its pattern along the height. (4) As height increase, there is a general tendency of the speed shift to downward on pores and the SMIs. This is more clearly seen on the other regions of stronger magnetic field. In this talk, we will present preliminary understanding of the coupling of pore dynamics between the photosphere and the low-chromosphere.

• Research in Community and Public Health Nursing
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• v.6 no.2
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• pp.259-274
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• 1995

The study is to grasp the problems related to operation of Maternity clinic of public health centers in seoul and needs for public health of community in relation to consumers and providers in order to improve efficiency of community public health for mothers and children. Four pregnancy woman, who receive medical care at the maternity clinic of M public health centers in seoul and understand the purpose of this study, and one nurse who works at the were the objects of this field study. Participating observation and intensive interviews were conducted to collect data. All of them were performed as necessary from time to time since December, 1994, and not during a specific period. Through an data analysis in the order of sector analysis and classification analysis, the data were classified into specific patterns and the results are the following; 1. All of the subjects were using both private hospitals and public clinics, but managing activities prior to delivery were not carried out in accordence with theories for those activities. 2. The subjects showed two types of response to utilizing maternity clinic. they answered that the advantages of the clinic were 'short waiting time for medical treatment', 'medical treatment by female doctors' and 'economical benefit.' Meanwhile, they gave negative response to the problems of 'non-implementation of delivery' 'uncleanness and insufficient facilities', 'limited time of treatment', 'lack of expertise' and 'want of public health education for materity.' 3. Problems related to operation of maternity clinic were 'lack of experts', 'irrational facility structure' and 'absolutely lack budget'. In terms of the status of managing the subjects, 'programs only aimed at attaining the central-government-assigned objects' and 'limited management before and after delivery by non-implementing delivery' were pointed out to be problems. Regarding public health education before delivery and PR relations, 'superficial public health education for maternity' and 'absence of PR programs' were named. In planning and evaluation, 'absence of autonomous planning and evaluation by the clinic itself' was a major problem in operating the clinic. 4. 'Substantial health education and PR', 'supplementation of facilities and eqipment', 'development' and supply of demanded service by the subjects', 'implementation of autonomous programs', and 'reinforcement of supplementary education' were presented as alternatives for efficient opration of maternity clinics.

• Journal of the Korea Concrete Institute
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• v.13 no.2
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• pp.107-113
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• 2001

This study was conducted preliminarily to develop the crack source location technique for plain concrete beam using acoustic emission(AE). Before the main experiment, the test of virtual An source location was achieved in plain concrete block. The sensor layout was mutually compared between triangular layout and rectangular layout. As the results of test, AE source location by triangular layout was evaluated more effective than that by rectangular layout. The specimen to apply he source location technique was man in total nine specimens (each three in 40 %, 50%, 60% of W/C ratio) which the experiment variable was the compressive strength level(W/C ratio). The bending loading method is selected by cyclic loadings to evaluate the degree of concrete damage. It is seen that Kaiser effect and Felicity effect exists through analysis of AE parameters in coming failure experiment. As a result of analyzing the felicity ratio(FR) values, it is shown that this values can be used for evaluating the degree of concerto damage. AE activity is started highly at the 70% of failure load without the compressive strength level. Thus considered by a index in constructing the system of the failure warning at application of the field structure. And the results compared the real cracking location with the source location has perceived by AE monitoring before it is appeared the primary crack by visual observation.