• Geotechnical Engineering
• /
• v.9 no.3
• /
• pp.67-76
• /
• 1993

Korea being composed of a number of mountains has been damaged and destroyed in lives and properties by the occurrence of many landslides during the wet seasons. Therefore, it is necessary to study the forecast system and risk analysis for the occurrence of landslides : the rise of groundwater levels due to rainfall is the main cause of landslides. In this paper, the autoregressive models are used to predict the grondwater levls using cases of both time invariant and time -varing autoregressive coefficients. In the former case, AR(1), AR(2), and AR(3) models are selected and their single-valued parameters are estimated to fit them to the observed groundwater level series. In the latter case, modified AR(1) and typical AR(2) models are used as process model and a discrete Kalman Filtering technique is utilized to estimate the parameters which are themselves a function of time. The results show that the real time forecast system using the time-varying autoregressive coefficinets as well as time -invariant AR model is good to predict the groundwater level in hillside slopes and we might get better result if we use the time-hourly rainfall intensity as well as the observed groundwater level.

• Development and Reproduction
• /
• v.2 no.1
• /
• pp.39-43
• /
• 1998

The synthesis of steroid hormone starts from cholesterol. Steroidogenic acute regulatory protein(StAR) transfers cholesterol acutely from the outer mitochondrial membranes to the inner in the early step of steroidogenesis. Many kinds of steroid hormones are mainly synthesized in adrenal grand, ovary and testis. The purpose of this study is to determine the distribution of StAR mRNA in the rat ovary and adrenal gland and to confirm the functions of StAR in these organs. In the ovary, StAR mRNAs were strongly expressed in the corpus luteum, where progesterone is synthesized, and these were weakly expressed in the theca layer of follicles, where androgen is synthesized. However, StAR mRNAs were not detected in the estrogen producing granulosa cells of growing follicles. In the corpus luteum, StAR mRNAs were strongly loclized in the zona fasciculata and zona reticularis, where glucocorticoid is mainly synthesized. StAR mRNAs were weakly expressed in the zona gromerulosa, where mineralcorticoid is synthesized. StAR mRNAs were not detected in the adrenal medulla. In our results, StAR mRNAs were expressed differentially in the steroidogenic cells of ovary and adrenal gland according to the types of steroid hormones, and the statges of corpus luteum development. We conclude that StAR is involved in the steroidogenesis at the very early step of steroid synthesis cascade.

• The Journal of Korean Association of Computer Education
• /
• v.12 no.5
• /
• pp.75-85
• /
• 2009

This study compared the differences between a group that studied with AR contents and a group that studied in a traditional method to examine the effects of AR contents use in elementary school science classes. The effects in four areas of studying were examined : study focus rate, study activities consuming variables, study participation activeness and instructional climate. As a result, there was no significant difference in study concentration rate between the AR and traditional groups. For study participation activeness, the AR group had higher participation actions, but there was no difference between the groups for language participation. For study activities consuming variables, the AR group stimulated more diverse study activities than the traditional group. For instruction climate, the AR contents group contributed more to creating a positive climate compared to the traditional group. Therefore, the results showed that application of AR contents on science classes would stimulate active participation of students and various study activities and help create a positive instructional climate.

• The Journal of the Petrological Society of Korea
• /
• v.12 no.2
• /
• pp.79-99
• /
• 2003

Muscovite and biotite from 52 metasediments and 5 granites in the Hwasan area, the southwest of the Okcheon metamorphic belt and the Miwon-Jeungpyeong area, central Okcheon metamorphic belt were dated by the K-Ar and $^{40}$ Ar/$^{39}$ Ar methods. Muscovite and biotite ages from metapelitic and psammitic rocks (metasediments) of the Boeun and Pibanryeong units in the Hwasan area are concentrated in the mid-Jurassic (149-180 Ma). K-Ar and $^{40}$ Ar/$^{39}$ Ar ages for metapelitic and psammitic rocks of the Boeun and Pibanryeong units in the Miwon-Jeungpyeong area show complicated age distribution. Muscovite and biotite ages are classified by three groups, 142-194 Ma, 216-234 Ma, and 241-277 Ma. Younger (Cretaceous) ages occur only in metasediments close to Cretaceous granitic rocks in the southeastern region and the older ages of 216-277 Ma are restricted to the middle Part of the Jeungpyeong area. Most ages in the other area of the central Okcheon metamorphic belt fall between 142-194 Ma (Jurassic). K-Ar and $^{40}$ Ar/$^{39}$ Ar ages for granite from the northern part in the both the southwest and central Okcheon metamorphic belt also gave middle Jurassic ages (156-168 Ma). The similar ages from both metasediments and granites in the study areas indicate simultaneous cooling of both rocks to 300-350$^{\circ}C$ during the middle Jurassic. The state of graphitization of carbonaceous material of all metasediments in the study areas Indicates fully ordered graphite falling within a small range, from 3.353 to 3.359 ${\AA}$, which indicate amphibolite facies regional metamorphism. In the southern sector of the Boeun unit from the Hwasan area, metamorphic grade indicated by mineral paragenesis during regional intermediate-P/T metamorphism is greenschist facies. Whereas, the $d_{002}$ values for carbonaceous materials in the same sector show fully ordered graphite (ca. 500$^{\circ}C$) indicating amphibolite facies. This result with the concentration of mica ages of metasediments into the middle Jurassic, the presence of low-P/T thermal metamorphic zone (>500$^{\circ}C$) in the metasediments close to the Jurassic granite and the regional intrusion of Jurassic granites and their middle Jurassic intrusion and cooling ages may indicate the low-P/T regional thermal event during the early(\ulcorner)-middle Jurassic after main intermediate-P/T metamorphism which formed main mineral assemblage regionally in the study area. The regional thermal event failed, however, to reset the mineral assemblage of regional intermediate-P/T metamorphism except for narrow aureole (1-2 km) around Jurassic granite because e duration of thermal effect was relatively short by repid cooling of the Jurassic granite. In the middle part of the Jeungpyeong area, central Ogcheon metamorphic belt, muscovite and biotite K-Ar ages from 5 samples are 263-277 Ma and 241-249 Ma, respectively. An intermediate-P/T metamorphism is currently accepted to have occurred between 280 and 300 Ma. Therefore, the muscovite and biotite ages can be interpreted as cooling ages after Ml metamorphism indicating rapid cooling to ca 350$^{\circ}C$ between 280-300 Ma and 263-271 Ma, and biotite ages indicate slower cooling to ca. 300$^{\circ}C$ between 263-277 Ma and 241-249 Ma. However, more detail study is needed to confirm why the Permian to Triassic ages occur only in the middle Part of the Jeungpyeong area.a.

• Journal of the Korean Chemical Society
• /
• v.44 no.3
• /
• pp.190-193
• /
• 2000

ab initio calculations are presented for M-Rg and M-Rg2 (M=Li, Na, Rg=He, Ar) van der Waals clusters.InternucIear distances and binding energies of LiHe, LiAr and NaAr obtained by all-electron MP2(6-311++G(3df,3pd)) method are in good agreement with experimental values. Calculated properties of LiHe$_2$, LiAr$_2$, NaHe$_2$ and NaAr$_2$ are also reported.

• Proceedings of the KIEE Conference
• /
• 2005.11a
• /
• pp.41-43
• /
• 2005

$Cl_2$ 플라즈마에 있어서 Ar 가스의 첨가에 의한 효과를 보기 위해 Ar 첨가 비율 rf 전력, 반응로 압력을 변화시켜가며 그 에너지와 질량을 분석하였다. Ar 첨가 비율에 따른 각 입자들의 질량 분석을 통해서, Ar의 비율이 80% 일 때 물리적, 화학적 반응이 최대가 되는 것을 확인하였다. 또한 Ar 첨가 비율에 따른 각 이온들의 에너지 분석을 통해, Ar 가스의 첨가에 의해 $Cl^+$ 나 $Cl_2^+$ 이온들의 이온 선속은 증가하나 그 에너지가 감소하는 것을 확인하였다. 반응로 압력과 rf 전력의 제어를 통해 이온 전류밀도, 이온 에너지와 전자온도를 제어 할 수 있음을 확인하였고, Ar 첨가 비율을 변화시키면서 전자 밀도 분포 함수의 변화를 관찰하여 이를 통해 Ar 비율에 따른 이온화 비율과 전자 온도, 밀도 등의 관계를 확인하였다.

• Journal of Information Technology Services
• /
• v.18 no.5
• /
• pp.85-97
• /
• 2019

In this study, we developed the Field-Experiential Learning Framework Using the Location Based Mobil-learning System (LBMS) and it is mobile Augmented Reality (AR) for smart learning system which is advanced e-learning. AR is technology that seamlessly overlays computer graphics on the real world. LBMS-AR has become widely available because of mobile AR. Mobile AR is possible to get information from real world anytime, anywhere. Nowadays, there are various areas using AR such as entertainment, marketing, location-based AR. We analysed the result of survey and implemented the functions. Also, for survey about application's effectiveness, we have focus group interview (FGI). Then we demonstrated and explained the application to them. The result of survey about application's effectiveness shows that application have higher utilization in education area. One of the most promising areas is education. AR in education shows lifelike images to users for realism. It's a good way for improving concentration and attention. We utilize only a beacone for image-based AR without other sensor.

• The Journal of the Convergence on Culture Technology
• /
• v.2 no.4
• /
• pp.49-54
• /
• 2016

Development of AR/VR has expanded computer games from indoor static contents to outdoor dynamic contents. The syndrome of 'Pokemon Go' which is a representative AR game was born, and Nintendo's stock price shot up a massive 120%. Although some people gained profits, new damages are emerging including illegal intrusion or road accidents because it is a type of game to visit real locations. There are reported about 114 thousand road accidents related to the game. This study aims to examine the trends of AR game in 2016 and analyze damages and positive cases to suggest a method for preventing accidents due to the AR game, and a business model.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.59 no.4
• /
• pp.417-422
• /
• 2010

Atmosphere Plasma of Gas Discharge (APGD) has been used in plasma sources for material processing such as etching, deposition, surface modification and so on due to having no thermal damages. The APGD researches on AC source with high frequency have been mainly processed. However, DC APGD studies have been not. In order to understand APGD further, it is necessary to study on fundamental properties of DC APGD. In this paper, we developed a one-dimensional fluid simulation model with capacitively coupled plasma chamber at the atmosphere pressure (760 [Torr]). Nine kinds of Ar discharge particles such as electron (e), positive ions ($Ar^+$, $Ar_2^+$) and neutral particles ($Ar_m^*$, $Ar_r^*$, $Ar_h^*$, $Ar_2^*$(1), $Ar_2^*$(3) and Ar gas) are considered in the computation. The simulation was worked at the current range of 1~15 [mA]. The characteristics of voltage-current were calculated and the structure of Joule heating were discussed. The spatial distributions of Ar DC APGD and the mechanism of power consumption were also investigated.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.05a
• /
• pp.288-290
• /
• 2017

Recently, interest and demand of Augmented Reality(AR) contents are increasing as an application field of AR. Generally, when the AR contents are served in the outdoor environment, the position information using the GPS signal is used to control the display of the object on the AR screen, or a marker based on the image of the object is used. However, there is a problem that location information can not be used in an indoor environment. If the service is provided using only the marker, there is a problem that the recognition of the marker due to the moving obstacle in the vicinity is unstable. and there is a problem that information displayed on the AR screen is not displayed in a fixed state at a specific position, it moves according to the movement of the camera. In this paper, we have studied the object control method for displaying the object to be displayed on the AR screen by using iBeacon using indoor location recognition and specific markers.