Earticle

Although camera traps have been widely used to understand the abundance of wildlife in recent decades, the effort has been restricted to small sub-set of wildlife which can mark-and-recapture. The Random Encounter Model shows an alternative approach to estimate the absolute abundance from camera trap detection rate for any animals without the need for individual recognition. Our study aims to examine the feasibility and validity of the Random Encounter Model for the density estimation of endangered leopard cats (Prionailurus bengalensis) in Maekdo riparian park, Busan, South Korea. According to the model, the estimated leopard cat density was 1.76 km-2 (CI 95%, 0.74-3.49), which indicated 2.46 leopard cats in 1.4 km2 of our study area. This estimate was not statistically different from the previous leopard cat population count (2.33±0.58) in the same area. As follows, our research demonstrated the application and usefulness of the Random Encounter Model in density estimation of unmarked wildlife which helps to manage and protect the target species with a better understanding of their status.

To know if small changes in rearing water temperature and density affect the number of bacterial and fungal colonies in metamorphosed frogs, Dybowski’s frog tadpoles were reared from Gosner 25-26 stages at either low (1°C low to ambient water temperature), ambient, or high (1°C high) water temperature (each 15 tadpoles in 20 L water) condition and at either low (10 tadpoles/20 L water), medium (20 tadpoles), or high (30 tadpoles) density condition. Immediately after metamorphosis, we sampled bacteria and fungi from skin, liver, and heart of six metamorphosed frogs, randomly selected for each treatment group. After separate incubation of bacteria and fungi on 3M Petrifilm plates, we counted the number of bacterial and fungal colonies appeared on the plates and compared the numbers among the temperature and density treatment groups. For temperature treatment, high-temperature group had fewer bacterial colonies, while low-temperature group had more fungal colonies than the other two groups. For density treatment, low-density group had fewer bacterial colonies than the other two groups, but the number of fungal colonies were not different among the groups. Our results suggest that small increased rearing water temperature and lowered rearing density could potentially reduce pathogens in farming frogs.

The variations of wood density and mechanical properties of Juniperus polycarpos trees were studied in a natural forest in Iran. Sample disks were taken from each tree to examine wood density and mechanical properties (MOE and MOR) from pith to bark at breast height, 50%, and 75% of total tree height. The analysis of variance (ANOVA) indicated that radial position and height significantly affected all wood properties. The wood density, MOE and MOR were decreased along horizontal position from the pith to the bark and vertical direction from base upwards. Regression analysis showed that modulus of elasticity (MOE) and modulus of rupture (MOR) had a positive correlation with wood density.

The effects of Mg content on the pore formation, density and critical properties were investigated in in-situ reacted MgB2 superconductors. The Mg1+xB2, (x=-0.2, 0.0, 0.05, 0.3, 1.0) bulk samples with different Mg contents were heat-treated at 900°C for 1 h in an Ar atmosphere. The dimensional changes of a pellet's mass and volume after heat-treatment were measured. After heat-treatment process, the sample mass was decreased by Mg evaporation, but the sample volume was expanded by pore formation at the Mg site; therefore, the apparent density was decreased. Spherical pores the same as Mg particles were developed after heat-treatment in all samples, and the pore density was increased with increasing Mg content. As the x of Mg content was increased to 1.0, the apparent density of Mg1+xB2 samples was decreased due to a relatively larger reduction in a mass change. The critical current density of Mg excessive sample of x=0.05 showed the highest values over the applied magnetic fields because the excessive Mg may compensate Mg loss and enhance grain connectivity.

거시적인 3대 교통변수(교통량, 속도, 밀도)와 고속도로 서비스 수준의 효과척도(밀도, 교통량 대 용량비) 모두 해당되는 변수는 밀도이다. 특히 도로의 서비스 수준을 평가함에 있어 가장 정확하고 우수한 효과척도로 알려져 있다. 이러한 중요성에도 불구하고 측정방법의 어려움으로 인해 타 변수에 비해 밀도를 활용한 연구가 상대적으로 부족하였다. 기존 밀도추정방법의 경우 측정시각에 따라 동일한 교통류의 밀도값이 변화하는 등의 한계가 있다. 본 연구에서는 서울외곽순환고속도로 사패산 터널 내부의 CCTV 영상을 정합하여 파노라마 영상을 제작한 후, 제작된 파노라마 영상을 이용하여 실제 밀도를 측정하는 방법을 연구하였다. 중심극한정리를 이용하여 분석한 결과, 1 km 사진 24개(혹은 24초)를 이용하여 밀도를 측정하면 당시 교통상황을 잘 반영할 수 있었다. 즉, 본 연구에서 제시한 밀도 수집 주기를 준수하여 수집한 구간영상으로 밀도를 측정할 경우 측정시각에 관계없이 평균적인 밀도값을 측정할 수 있으며, 현실 교통류를 대변하는 현실적인 밀도를 취득할 수 있다.

Density is applied both three major macroscopic traffic variables (traffic volume, speed, and density) and two measures of effectiveness (MOE) for level of service (LOS) on highway (density and V/C). Especially, it is known for the most accurate MOE on evaluating the LOS of highway. Despite such importance, there is a lack of study on density relatively than other variables for its difficulty of measurement. Existing density estimation methods have some limitations such as density values of same traffic flow vary with collecting time. In this study, we researched actual density measuring method with panoramic image, after each CCTV images in the Sapaesan Tunnel on Seoul Ring Expressway are matched into one panoramic image. Analysis through the Central Limit Theorem shows that density of 24 1 km-images, which means 24 second, applies traffic situation well. That is to say that reasonable density value regardless of collecting time, and practical density which represents actual traffic flow can be taken in case of measuring density by suggested collecting cycle.

This study was conducted to examine the utilization of sawdust and wheat offal hybrid for the production of briquettes for sustainable livelihood. The feedstocks (Sawdust [SD] and Wheat offal [WO]) were collected, dried to 12% moisture content and milled for size homogeneity. SD and WO were mixed at different ratios and used for briquette production (SD-100:0, MIX1-75:25, MIX2-50:50, MIX3-25:75, and WO-0:100). The mixture was fed into a 5-ton hydraulic jack briquetting machine at pressure of 2.4 MPa. All the parameters determined were carried out using ASTM Standard procedures except for Stability and Porosity index. Both physical and combustion properties were statistically analyzed using ANOVA at 95% confidence level. The result of the physical properties of briquettes shows that MIX2 produced using 30% binder recorded highest density (500.97 kg/m3) and lowest density in SD (402.04 kg/m3). It was observed that SD produced at a 30% binder level had the lowest moisture content (5.22%), while SD produced at 20% binder level had moisture content of 5.22%. The result further shows that MIX2 produced at 30% binder level had lowest (50.6%) porosity index and highest (70.32%) in WO at 20% binder level. The result of the stability of briquettes shows that stability of briquettes at a 30% binder level was found to be more linear and stable compared to the 20% binder level. Shatter index of MIX2 at 30% binder level gave higher shatter index (97.72%) compared to 90.39% obtained at 20% binder level. Combustion properties shows that WO at 30% binder have highest volatile matter 27.00%. On the other hand, SD had the lowest ash content of 5.5% and highest calorific value of 34.54 MJ/kg1 at 20% binder level. This is an indication that binder level and biomass type influenced the properties of briquettes.

Twenty-five Eucalyptus clones (14 E. camaldulensis - EC and 11 interspecific eucalypt hybrid clones - EH) grown in three contrasting sites were evaluated for the growth and few wood traits at 4 years of age. The stability, genotype-site interaction and suitability of these clones for pulp and solid wood industry sectors were studied. Growth of eucalypt clones was significantly higher at site 1 with higher rainfall, but wood density did not differ significantly from lower rainfall sites. Kraft pulp yield (KPY) decreased from sites 1 to 3 based on moisture availability, but not between two groups of clones. Volumetric shrinkage (VS) was significantly higher in EC clones at site 3 with lowest rainfall, but there was no specific trend at other two sites with maximum (site 1) and intermediate (site 2) rainfall. The mechanical traits modulus of rupture (MOR) and modulus of elasticity (MOE) were at par in sites 1 and 2, but significantly lower at the driest site 3. The growth rate had a significant positive correlation with KPY, MOR and MOE and a negative correlation with VS, but no significant impact on wood density in both groups of clones. Genotype×environment interaction (G×E) was evident in most traits due to the difference in response of clones to moisture availability. Since wood density was negatively correlated to KPY, it has to be kept at an optimum level for the profitability of pulp industry. There was no significant difference between EC and EH clones for most traits except VS at site 3. Stability of clones varied across sites in different traits, and hence clones may be selected for deployment at each site by screening for growth, followed by wood density, considering the relationship of growth and density with other traits required by pulp and solid wood industry sectors.

본 연구는 오프셋 인쇄에서 UV 인쇄와 LED-UV 인쇄의 품질을 비교·분석하였다. 그 결과 인쇄물의 색 농도 값은 백상지에 비하여 아트지와 유포지에서 상대적으로 높 게 나타내었다. 특히 UV 인쇄가 LED-UV 인쇄보다 색 농도 값이 상대적으로 높게 나 타났다. 트래핑 특성으로 재현되는 R, G, B의 경우에는 색 농돗값이 ISO12674-2 규격 보다 높게 나타났다. 또한 트래핑은 UV 인쇄가 중첩된 색 농돗값 0.1정도의 근소한 차 이로 LED-UV 인쇄보다 높은 것으로 확인되었다. 그레이 밸런스에서는 CMY로 재현된 그레이의 오차 범위 평균이 타깃 오차 범위인 색차(ΔE* 00) 2를 넘지 않았다. 망점 확대의 경우 UV 인쇄와 LED-UV 인쇄에서 아트지 와 유포지가 상대적으로 잉크의 흡수와 번짐 현상이 적은 양호한 결과를 나타내었다. 특히 망점 확대율의 경우 LED-UV 인쇄가 UV 인쇄보다 평균 1.8% 정도 낮게 나타났 다. 색차의 경우 M 잉크를 제외한 모든 잉크에서 백상지와 아트지는 5.0 이내, 유포지 는 5.0을 벗어나는 결과를 보였다. 또한 전체적인 LED-UV 인쇄가 UV 인쇄보다 색차 가 적어 양호한 결과를 나타내었다.

This study compared the quality of UV and LED-UV printing in offset printing. As a result, the color density value of printed matter was relatively higher on art paper and artifical paper than on wood-free paper. In particular, UV printing showed relatively higher color density values than LED-UV printing. In the case of R, G, and B, which are reproduced as overprinting characteristics, the color density values were higher than the ISO12647-2. It was also confirmed that the trapping was higher than the LED-UV printing with a slight difference of about 0.1 in the overprinting color density value of the UV printing. In gray balance, the average error range of gray reproduced by CMY did not exceed the target error range of ΔE* 002 . In the case of dot gain, art paper and artifical paper showed good results with relatively little ink absorption and smearing in UV and LED-UV printing. In particular, in the case of dot gain rate, LED-UV printing showed an average of 1.8% lower than UV printing. In the case of color difference, wood-free paper and art paper showed results within 5.0 and artifical paper exceeded 5.0 in all inks except for M ink. In addition, overall LED-UV printing showed good results with less color difference than UV printing.

Due to the occurrence of social problems caused by wild boar(Sus scrofa), information on the scientific habitat of wild boar living in the city type national park is required. This study was carried out to establish a scientific management plan through identification of the ecological characteristics of wild boar in Bukhansan National Park(BNP). Monthly average number of wild boar was 91.8 individuals with an average density of 1.9 indiv./㎢ in BNP. The frequency of wild boar was the highest in the site 2, and the mud bath was preferred. The wild boar was most frequently seen at 7pm and was confirmed to be nocturnal. The average home range of the wild boar was 1.043±0.378㎢, and the core area was 0.010 ± 0.001㎢. In order to prevent wild boar from appearing, In order to prevent wild boar from appearing in the city, it was found to be effective as a result of installing a fence and capture frame. However, the placement of specialist personnel who can manage the facilities is very important. The management plan of wild boar in BNP needs to understand trend of density change through long-term monitoring and to construct data through basic ecological research.

Recently, as increasing of demand for passive house and green house as low energy green building, development of lightweight insulation materials by using natural resource will be an important part for establishing green building technology in the future. Wood fiber insulation board (WFIB) can be a one of the key material for low energy consumption, comfortable, and safety construction of residential space because of its eco-friendly and high thermal insulation performance. This study was carried out to compare the characteristics of WFIBs manufactured with different conditions. WFIBs (20 mm (T), 0.10 g/cm3) were successfully manufactured by melamine-urea-formaldehyde (MUF), phenol-formaldehyde (PF), and emulsified MDI (eMDI), and latex resins. Thermal conductivities of all WFIBs were 0.037 W/m∙K which was similar insulation performance with extruded polystyrene foam. A 20, 25, 30, and 35% resin contents of melamine-urea-formaldehyde (MUF) was used for preparing of WFIB and then their properties were compared. There was almost no effect on the insulation performance of WFIBs. To investigate optimum density, WFIBs were prepared in 0.10, 0.15, 0.20 and 0.25 g/cm3. The higher thermal conductivity (0.037 W/m∙K) was observed on the WFIB at 0.15 g/cm3 density, and thermal conductivity tended to gradually increase to 0.043 ~ 0.046 W/m∙K as density increase. The optimum conditions of WFIB could be about 0.15 ~ 0.20 g/cm3 density with 25% resin contents of MUF for securing both insulation performance and human body and structural safety.

본 연구는 경주 단석산 상부 남사면의 상수리나무 우점 식분의 군집구조 변화를 파악하기 위하여 고정 방형구 20개를 설치하고 1999년부터 2018년까지 5회의 매목조사를 실시하였다. 밀도는 1999년에 0.33에서 2012년에 0.20으로 감소하였으나 2018년에는 0.24로 다소 증가하였다. 전체 수목의 흉고직경계분포를 보면, 1999년에는 역J자 유사한 모양의 분포를 나타내었으나 그 후 분포가 변화되어 2018년에는 어린 개체들에서는 역J자 모양이, 성숙한 개체들에서는 종 모양이 나타나 전체적으로는 두 곡선이 연결된 형태의 분포를 나타내었다. 흉고직경 13cm이하에서는 수목들의 경쟁이 심하였으나 그 이상에서는 완화되는 것으로 나타났다. 최우점종인 상수리나무의 흉고직경계 분포는 종 모양의 분포를 보였고, 시간이 지남에 따라 흉고직경이 큰 쪽으로 분포가 이동하지만 개체수는 줄어들었고, 신갈나무는 낮은 종 모양의 분포가 점점 높아지는 변화를 보였다. 흉고직경계분포의 변화로 볼 때, 단석산의 상수리나무 식분은 이차천이의 초기 단계에서 중간 단계로 삼림천이가 진행 중인 것으로 판단이 되며, 현재 본 식분의 최우점종은 상수리나무이고 준우점종은 신갈나무이지만, 향후 신갈나무가 최우점종인 식분으로의 천이가 진행될 것으로 예상된다.

This study was carried out to clarify changes in community structure of Quercus acutissima dominant stand on the south slope of Mt. Danseok-san with fixed twenty quadrates. Five field surveys were conducted from Aug. 1999 to May 2018. During the period, the density lessened to 0.20 in 2012 comparing with 0.33 in 1999. However recent field study in 2018 showed moderate rising to 0.24. In 1999, the DBH class distribution of all trees formed reverse J curve. However, the reverse J curve was torn down, forming bell curve. In 2018, the curve showed similar shape of reverse J shape on the group of young trees, forming bell shape on the group of mature trees. It reveals that DBH 13cm is on the threshold of trees competition trend where the downtrend in the trees are on uptrend. The most dominant Q. acutissima formed bell curve. The peak of the curve shows the shift to the right of the graph as it gets lower by year.In case of Q. mongolica, shows a change in the shape of a low bell as the distribution curve increases. The oak stand in this study is in the process of changing from the initial stage of the secondary forest succession to the intermediate stage. The most dominant tree is Q. acutissima, and the sub-dominant tree is Q. mongolica in present. Considering the age distribution of the two competing tree species, the succession of this stand is expected to transfer to the Q. mongolica-dominant community.

Among the domestic softwoods, technical value of Pinus koraiensis small diameter logs which have comparatively low applicability was evaluated and sensitive characteristics and physical characteristics were investigated and analyzed for examining if it can be utilized as the interior decoration material. For the sensitive characteristics of Pinus koraiensis, wood figure, wood grain, wood color and odor were evaluated and for the physical characteristics, growth-ring width and latewood percentage, abrasion, density, shrinkage, swelling, absorption, roughness and hardness were evaluated. Then, the possibility to be developed as the interior decoration material was found. As the result of evaluating sensitive characteristics and physical characteristics of domestic Pinus koraiensis, wood figure, wood grain, color and scent clearly were judged to have excellent visual factor as the interior decoration material. And, physical characteristics were also judged to be excellent, so it is judged to be developed as the interior decoration material. Therefore, as the result of various forms of design pattern with domestic Pinus koraiensis small diameter logs, several patterns of interior decoration can be developed by characteristics of each side and colors of heartwood and sapwood. And, in the future, it can be applied to furniture design or interior decoration material for the proper use. Especially, it is considered to contribute to wood applying industry through the study on the quality of domestic small diameter logs which have low applicability.

Customer retention has been an important issue in the competing environment. Lots of researches focus on prediction of the churning customers and seeking the characteristics of them. However, relationships among customers or products have been considered in the existing researches. In this study, a product network is proposed to investigate the differences of network characteristics of products purchased by churning customers and loyal customers through the real purchase data of a Korean department store. We investigated whether degree centralities, densities and degree centralization of the networks of product purchased by churning customers and the loyal customers are different. Our results indicate that degree centrality, density and degree centralization of the product network of churning customers are higher than those of the loyal customer. We expect that the suggested social network analysis is used to as a complementary analysis methodology for predicting the churning customers and seeking the characteristics of them.

본 연구는 경기도의 경안천 습지에서 번식 조류의 둥지 장소로서의 정수식물에 대한 선호성을 알아보고자 수행되었다. 6종의 조류가 정수식물에 번식하였으며 물닭 Fulica atra, 쇠물닭 Gallinula chloropus, 개개비 Acrocephalus orientalis, 덤불해오라기 Ixobrychus eurhythmus, 논병아리 Podiceps ruficollis, 뿔논병아리 Podiceps cristatus 등의 둥지가 발견되었다. 둥지 장소로 이용한 곳은 애기부들 Typha angustata, 갈대 Phragmites communis 와 줄플 Zizania latitolia 이었다. 특히 애기부들은 번식조류가 가장 선호하는 곳이었다. 그에 비해 쓰레기가 쌓인 곳이나 밀도가 빽빽한 곳은 둥지가 거의 없었다. 내부의 덤불에서는 둥지가 전혀 발견되지 않았다. 소택지 내 둥지의 평균 밀도는 3.1개였으며 논섬이 17개/ha 로 밀도가 가장 높았다. 둥지 밀도는 소내섬 주변 지역이 광동교 인근보다 높았다. 이것은 애기부들의 규모와 수질과 관련될 것으로 보인다.

This study was conducted on the marsh of Paldang dam and Gyungan-cheon, Gyeonggi-do province. 6 species bred on the emergent plants and the nests of Common Coots Fulica atra, Common Moorhens Gallinula chloropus, Great Reed-Warblers Acrocephalus orientalis, Yellow Bitterns Ixobrychus eurhythmus, Little Grebes Podiceps ruficollis and Great Crested Grebes Podiceps cristatus were found. The main vegetations of the nests were Narrow Leaf Cattails Typha angustata, Reeds Phragmites communis, and Wild Rices Zizania latitolia. Particularly, Narrow Leaf Cattails were the most favorite plants for breeding birds. Few nests were found on the emergent plants covered with rubbish, or on high density. And no nests found on the inside shrubs. The mean density of nests on the marsh was 3.1 nests per ha and the nests were highest in Non-island as 17 nests per ha. The nest density on the area of Sonae-islands was higher than the area of Kyangdong-kyo bridge. This would be related on the bulk of narrow-leaf cattails and the quality of water.

순천만에서 갈대군락이 저토의 이화학적 특성에 미치는 영향과 갈대군락의 증가형태를 파악하기 위해 1999년과 2000년에 갈대군락의 폭을 측정하고 2007년에 갈대군락의 형성정도에 따라 3개 지역을 선정하여 깊이별 저토의 수분함량, 염분농도, 유기물함량, 황함량, 질소함량, 탄소함량 및 수소함량을 조사하였다. 갈대군락의 유무와 관계없이 육지와 멀리 격리되어 있을수록, 수로와 가까이 있을수록 저토 내 수분함량이 많고 염분도가 높았다. 또한 표층의 유기물함량은 갈대의 현존량과 비례하였지만 하층의 것은 오래된 갈대군락에서 오히려 낮았다. 황함량은 나지(0.23%)나 근래에 형성된 갈대군락(0.21%)보다 오래된 갈대군락(0.33%)에서 높았고, 탄소, 질소 및 수소의 함량은 표층에서 현저히 높고 하층에서 낮아 대체로는 유기물함량과 유사한 경향성을 보였지만 하층으로 감에 따라 감소하거나 증가하는 경향은 일치하지 않았다. 갈대군락 폭의 증가는 1999년에 2.33±0.73 m, 2000년에 3.65±1.64 m이었으며 연도에 따라, 군락에 따라, 방향에 따라 다양하여 일정한 경향성이 없었다. 이러한 갈대군락의 증가 특성에 의해 시간의 경과에 따라 전체적으로 원형의 군락을 이루는 것으로 생각되었다. 매해 증가한 지역에서 갈대의 밀도와 초장은 가장자리로 갈수록 감소하였다. 또한 하나의 군락에서 밀도는 방향(육지 혹은 해양)에 따른 경향성은 없었으나 초장은 북쪽 혹은 육지방향이 남쪽 혹은 해양방향보다 작은 것으로 나타났다.

To clarify the reed (Phragmites australis) stand's effects on the sediment properties and its increasing pattern, breaths of reed stands in 1999 and 2000, and sediment properties - water, salt, organic matter, sulphur, nitrogen, carbon and hydrogen contents - along th depth at the three stands in 2007 were surveyed at Suncheon Bay. Regardless of reed stand, the more distance from the land was long, the more water and salt contents of sediment were high. Organic matter content of sediment was high and increased with the reed biomass at the upper layer but low regardless of biomass at the lower layer. Sulphur content of sediment was higher at old reed stand (0.33%) than at new stand (0.21%) or non-vegetated stand (0.23%). Carbon, nitrogen and hydrogen contents of sediment were similar at three stands in mean values. However, their contents were high at upper layer and low at lower layer in a stand. Therefore, the changing pattern of organic matter content with the depth was similar to but not coincided to the inorganic nutrients' ones. The mean breadth of reed stands increased 2.33±0.73 m in 1999 and 3.65±1.64 m in 2000. However, the increase of reed stands' breadth a year varied along the direction, year or stands, so that there was not a trend in increasing pattern. It was thought that this increasing pattern made the reed's patch round. The height and density of reed shoot in newly formed stand decreased with the distance from the center of stand. In the newly formed peripheral area of a reed stand, the shoot density was not related with the land (north) or sea (south) direction, however, the shoot height was higher in the sea (south) than in the land (north) direction.

The Second Phase New Town development is in process, since 2000. So, the evaluation on the on going project is not proper. However, the planning indices, planning tools, and ways of developments can be compared, between the First Phase and Second Phase New Towns. The level of physical environments is actually advanced, than that of the First Phase, especially the planning techniques such as eco-planning, mass transit, and U-city planning are strikingly advanced.However, the reconfiguration of spatial structure in SMA, land compensation and management of the bordering area, sharing of infrastructure cost, and the provision of rental housing is still debating issues.

이 연구의 목적은 학교에서 형성되는 의사소통 네트워크 특성을 분석함으로서 교원들 간의 상호 공조 네트워크 구축 및 단위학교의 운영 개선에 시사점을 주고자 하였다. A고등학교에 근무하는 94명의 교사를 대상으로 설문 조사와 면담 조사를 실시하였으며, 수집한 자료는 네트워크 분석법을 적용하여 분석하였다. 분석 결과, 의사소통 영역별로 교원들 간에 강한 연결, 약한 연결 혹은 집중형 구조, 분산형 구조의 모습을 보이며 다양하게 네트워크가 형성되어 있다. 대표적으로 교수-학습 네트워크는 약한 연결, 성긴 네트워크를 보였으며, 행정․사무 네트워크는 중앙 집중적이고 위계적인 특성을 보였다. 각 네트워크의 스타는 부장교사가 차지하고 있었다. 이러한 결과를 바탕으로 교수-학습 네트워크의 활성화, 업무 집중 현상 개선, 의사소통 네트워크 연구에 대한 자료축적을 제언으로 제시하였다.

The major concern of this study is to shed light on the characteristics of communication networks between teachers through a case of "A" high school. The major findings of this study are as follows. Firstly, in the Teaching and Learning communication network, the number of interactions per a teacher is smaller than those of any other, with the weak ties. On the other hand, the Student Discipline and Guidance communication network appears to be densely and tightly tied, with the most linked teachers and the fewest isolated teachers. The Personal and Daily Life communication network is the second in the interaction frequency. The School Management and Administration shows a strong inclination to a 'star' and has the features of a hierarchical structure. Secondly, the interactional characteristics of each networks shows that the Teaching and Learning network is the lowest both in the average communication frequency and in the helpfulness of the communication. The key factor that makes relationship with others was reported 'the adjacency of working places in a school'. Thirdly, the actors' characteristics of networks were investigated with the centrality index. The 'stars', those who have the highest centrality, are head teachers or the teachers with rich careers. In the variables of teacher position, the central index of teachers of high position including head teachers was high at the three domains except the Personal and Daily Life domain.