• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.407-412
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• 2002

The primary cause of missing teeth vary depending on the region. The loss of posterior teeth is mainly due to dental caries, whereas that of the anterior teeth occur primarily due to trauma at the age of standing and walking and secondarily from the rampant dental caries. Particularly, reduction of the arch length in the cases of premature loss of primary teeth may compromise the eruption of succedaneous permanent teeth. This may result in crowding and impaction of the permanent teeth, and asymmetry of arch, thus a careful consideration for space maintenance should be made in such cases. Space maintainer is required in the case of premature loss of primary posterior teeth, because space loss result from the approximate and centrifugal movement of the neighboring teeth. Generally, in the case of primary incisor, space loss occurs when 1) tooth contact is relevant, 2) crowding in primary dentition is present, and 3) a primary incisor is lost before the eruption of primary canine. Contrarily, in the case of primary dentition with interdental space, space loss will not be observed, mostly when a primary incisor is lost after the eruption of primary canine. Thus, using a space maintainer in cases of premature loss of primary incisor has been introduced primarily not for the purpose of space maintaining but for an aesthetic purpose, prevention of parafunctional oral habits such as tongue thrust, and of pronunciation. Additionally, few case studies have been reported of space loss in cases of premature loss of primary incisor. This study is to report cases of the space loss following the premature loss of primary incisors observed in children.

• The Journal of the Acoustical Society of Korea
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• v.22 no.7
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• pp.579-584
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• 2003

All of propagation path loss prediction models, which have been presented up to date, are oかy for ground living space. In reality, sea surface free space is different from ground living space in physical hierarchical structure. If the propagation path prediction model for ground living space is applied to the sea surface free space, propagation path loss will be smaller than actual value, while the maximum service straight line will become shorter. Thus this paper proposed and simulated the propagation path loss prediction model for predicting propagation path loss more accurately in sea surface free space, with its focus on CDMA mobile communication frequency band. Then the simulation results were compared to actual survey to verify its practicality.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.223-226
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• 2004

This paper analyzes the accuracy of free space path loss and matched filter gain approximated by using a passband rectangular pulse for ultra wideband (UWB) radio systems. The example causal signal, a modulated Gaussian pulse with the same center frequency and frequency bandwidth of the passband rectangular pulse, is used to consider the accuracy. The path loss and matched filter gain of the modulated Gaussian pulse are simulated for the reference results. The UWB free space path loss is shown and is compared with that obtained from simulation and Friis' transmission formula. The UWB matched filter gain is shown and compared with simulation results. From the results, we can see that the UWB path loss formula is more accurate than the Friis' transmission formula. The results from the UWB free space path loss and matched filter gain formulas agree with the simulation. Then, these free space path loss and matched filter gain formulas approximated by using a passband rectangular pulse are appropriate for UWB system.

• Journal of Korean Society of Rural Planning
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• v.22 no.4
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• pp.37-47
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• 2016

The purpose of this study was to analyze the loss of open space of schools in Ulaanbaatar city and found out main causes of the conversion trend of open space to suggest alternatives. 76 designated sites were selected from 118 public schools within 6 districts of Ulaanbaatar city. These 76 schools were eligible for analysis of the open space change between 2005 and 2015 with Google Earth Pro. The results showed that $175,048m^2$ open space was developed and two dominant types of open space conversion were found; 1) constructions of school facilities such as soccer field, extended school buildings, parking lot, sidewalk, and square, and 2) constructions of apartment buildings and service facilities such as community center, pedestrian, sports facilities, and parking lot. Apartment complex development has commonly happened in all districts and caused bigger open space loss than other types of development. Chingeltei district is located in the center of Ulaanbaatar city, and schools in this district lost the biggest open space, $50,036m^2$/35.24% over 10 years. The rate of open space loss seemed to be related to the distance from the urban center and open space loss was an ongoing event in Ulaanbaatar city. This trend would not be improved without a strong regulation, so, in this study, making strict regulations that prevent conversions of open space were suggested to conserve open space in Ulaanbaatar city.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1991.10a
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• pp.141-144
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• 1991

In this paper, we analyze the performance of ATM switch with output buffer which has a space priority control mechanism. As we assumed that the input traffic consists of loss tolerable voice and loss sensitive data, we modeled it with MMPP(Markov Modulated Poisson Process). We confirmed that the loss probability of loss sensitive traffic decreases when we use the space priority control mechanism.

• Bulletin of the Korean Space Science Society
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• 2004.04a
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• pp.39-39
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• 2004

It has been known that ring current particles can be lost through dayside MP(magnetopause). However, details of the loss mechanism of this process has not received much attention. In this study, we show that the solar wind dynamic pressure P$\sub$D/ can play a significant role in the dayside loss. In order to show that, we have first conducted superposed epoch analysis using 95 geomagnetic storm events selected from the period 1997 to 2002. (omitted)

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.4
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• pp.776-780
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• 1997

Patient with alveolar abscess due to dental caries with severe alveolar bone loss, severe tooth mobility, root resorption need extraction of tooth because it is impossible to carry out pulp treatment and restoration by using conventional method. Early loss of primary molar might cause masticatory interference, extrusion of opposing tooth, problem in maintaining space and interference on eruption of permanent tooth. Especially, early loss of primary second molar before the eruption of permanent first molar might cause space closure by mesially erupted permanent first molar and impaction of second premolar. In such a case, distal shoe space maintainer and removable space regaining appliance was the first choice of treatment. But, distal shoe space maintainer need precise adaptation and might cause chronic inflammation if the oral hygiene is poor. In a case using removable space regaining appliance, patient's cooperation is most important. If the distal root of primary second molar is comparably sound and alveolar abscess with alveolar bone loss is localized at mesial root, hemisection should be carried out for precise guide to eruption of the permanent first molar, restoration of masticatory fuction and solution to the discomfort of the patient

• Journal of Family Relations
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• v.22 no.3
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• pp.73-101
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• 2017

Objectives: This study is to understand the experiences of overcoming pain of loss of family survivors in Suicide Bereavement Support Group(SBSG). Method: Experiential data was collected by in-depth interview(FGI, individual) to 10 family survivors(over 19) who having an experience participating in SBSG over 5months and analyzed using qualitative methodology. Results: We drew the result that 'SPACE model' which structuralize by 5 stages of suicide survivors' experience of SBSG of time path. SPACE model configured as follow: Stage1, Space in vacuum, the time to feel a sense of overwhelming feeling like pain, fear, alienation after loss of suicide, Stage2, Probing, when to find informations and resources to help survivors themselves, Stage3, Acclimation, having experiences empathy and healing as in SBSG, Stage4, Composure, accepting SBSG meaning as a part of their lives, loss of my family by suicide, and the beginning of bereavement, Stage5, Endurance, overcoming suffering through SBSG and try to help other survivors. Conclusions: SBSG is the opportunity for family survivors to overcome the pains from loss of suicide, shock, anger, grief, etc., and to empower them to help other suicide survivors.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.3
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• pp.194-198
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• 2011

In this paper, we obtained the path loss characteristics in the 850 MHz for Russia area by using the free space path loss model and Okumura-Hata path loss model. In order to extract the additional path loss model parameter from the new Russian regional properties, the mean square error technique is used to obtain the correction factor. According to the obtained correction factor, the differences for the free space and Hata path loss model are 17, 6 dB in the 5 ~ 10 Km, 28, 14 dB in the 10 ~ 15 Km, and 35, 18 dB in the 15 ~ 20 Km. By applying the correction factors, the appropriate partial path loss models for the measured Russain area are proposed.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.62.3-63
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• 2017

The Mars Atmosphere and Volatile (MAVEN) mission has been providing valuable information on the atmospheric loss of Mars since its launch in November 2013. The Neutral Gass and Ion Mass Spectrometer (NGIMS) onboard MAVEN, was developed to analyze the composition of the Martian upper atmospheric neutrals and ions depending on various space weather conditions. We investigate a variation of upper atmospheric ion densities depending on the interplanetary coronal mass ejections (ICMEs). It is known that the Mars has a very weak global magnetic field, so upper atmosphere of Mars has been strongly affected by the solar activities. Meanwhile, a strong crustal magnetic field exists on local surfaces, so they also have a compensating effect on the upper atmospheric loss outside the Mars. The weak crustal field has an influence up to 200km altitude, but on a strong field region, especially east longitude of $180^{\circ}$ and latitude of $-50^{\circ}$, they have an influence over 1,400km altitude. In this paper, we investigated which is more dominant between the crustal field effect and the ICME effect to the atmospheric loss. At 400km altitude, the ion density over the strong crustal field region did not show a significant variation despite of ICME event. However, over the other areas, the variation associated with ICME event is far more overwhelming.