• Title, Summary, Keyword: Genesis location

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Characteristics of Tropical Cyclone Activity Influenced by Decadal Variability of SST (해수면 온도의 10년 주기 변동에 영향을 받는 Tropical Cyclone의 특징)

  • Kim, Dong-Hyeok;Kang, In-Sik
    • Atmosphere
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    • v.18 no.4
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    • pp.485-492
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    • 2008
  • This study confirms that a decadal variation of the SST (Sea Surface Temperature) in the WNP (Western North Pacific) has an influence on the genesis and passage ofa Tropical Cyclone. The decadal mode was obtained by calculating the SST anomaly on the domain $150^{\circ}E-190^{\circ}E$, and $5^{\circ}S-5^{\circ}N$. Such decadal variation was subsequently analyzed to confirm that it is a dominant mode in central Pacific region. Next, after classifying the years into relatively positive years and relatively negative years, the characteristics of Tropical Cyclone in each year, such as a genesis and passage frequency, were investigated. Compared to the relatively negative years, during the relatively positive years, the location of Tropical Cyclone genesis was biased toward South-Eastern region, while the characteristics of the cyclone were more distinct during late season of the year trom September to December than in mid season from June to August. Examining the movement passage through the observation of passage fiequency, there was a significant difference between positive year and negative year in their passages at a 90% confidence level. Moreover, the number of Tropical Cyclone, maximum wind, and life time also showed higher values in positive years than in negative years. These features were confirmed by examining the 850hPa cyclonic flow field, vorticity field, and vertical wind shear field, all of which contribute to the genesis of a Tropical Cyclone.

Characteristics of Tropical Cyclogenesis over the Western North Pacific in 2007 (2007년 북서태평양에서의 열대저기압 발생 특징)

  • Choi, Ki-Seon;Kim, Baek-Jo;Lee, Seong-Lo;Kim, Ho-Kyung;Park, Jong-Kil;Lee, Ji-Sun
    • Journal of Environmental Science International
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    • v.18 no.5
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    • pp.539-550
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    • 2009
  • This study found that tropical cyclones (TCs) formed for fall in 2007 over the western North Pacific were distributed in high-latitudes comparing to 56-year (1951-2006) climatological mean. The frequency and latitude of TC genesis became higher than 56-year climatological mean from September onward in 2007 and all the TCs that formed to the north of 20$^{\circ}$N was also distributed after September in 2007. These characteristics of TC genesis for fall in 2007 could be confirmed through analyzing various variables, such as a large-scale atmospheric circulation, outgoing longwave radiation (OLR), vertical zonal wind shear, and sea surface temperature (SST). On the other hand, a frequency of the TC that occurred to the north of 200N showed a clear interdecadal variation and its decreasing trend was distinctive in recent years. Its intensity was also weaker that TCs that did to the south of 20$^{\circ}$N. However, a latitude of TC genesis showed an increasing trend until recent years, whose variation was consistent with trend that through a SST analysis, warm SST went north in recent years.

Prediction of Tropical Cyclone Intensity and Track Over the Western North Pacific using the Artificial Neural Network Method (인공신경망 기법을 이용한 태풍 강도 및 진로 예측)

  • Choi, Ki-Seon;Kang, Ki-Ryong;Kim, Do-Woo;Kim, Tae-Ryong
    • Journal of the Korean earth science society
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    • v.30 no.3
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    • pp.294-304
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    • 2009
  • A statistical prediction model for the typhoon intensity and track in the Northwestern Pacific area was developed based on the artificial neural network scheme. Specifically, this model is focused on the 5-day prediction after tropical cyclone genesis, and used the CLIPPER parameters (genesis location, intensity, and date), dynamic parameters (vertical wind shear between 200 and 850hPa, upper-level divergence, and lower-level relative vorticity), and thermal parameters (upper-level equivalent potential temperature, ENSO, 200-hPa air temperature, mid-level relative humidity). Based on the characteristics of predictors, a total of seven artificial neural network models were developed. The best one was the case that combined the CLIPPER parameters and thermal parameters. This case showed higher predictability during the summer season than the winter season, and the forecast error also depended on the location: The intensity error rate increases when the genesis location moves to Southeastern area and the track error increases when it moves to Northwestern area. Comparing the predictability with the multiple linear regression model, the artificial neural network model showed better performance.

최소 자원을 사용하는 저전력 데이터 패스 할당 알고리즘

  • 문성필;김영환
    • Proceedings of the IEEK Conference
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    • pp.75-78
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    • 2000
  • This paper presents a new algorithm for allocating the data path to achieve the minimum power consumption under the constraints of minimum hardware resources. In order to minimize the power consumption, the proposed algorithm tries to minimize the input transitions of functional units, unnecessary computations, and size of interconnects in a greedy manner during a]location. Experimental results using benchmarks indicate the proposed algorithm achieves 17.5% power reduction on average, when compared with the genesis-lp[1]high-level synthesis system.

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Early Result of Demineralized Bone Matrix (DBM, Genesis$^{(R)}$) in Bone Defect after Operative Treatment of Benign Bone Tumor (양성 골 종양의 수술적 치료 후 발생한 골 결손에서 탈무기화 골 기질(DBM, Genesis$^{(R)}$)의 단기 결과)

  • Seo, Hyun Je;Chung, So Hak
    • The Journal of the Korean bone and joint tumor society
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    • v.19 no.2
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    • pp.56-63
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    • 2013
  • Purpose: This study was performed to evaluate the efficiency of demineralized bone matrix (DBM, Genesis$^{(R)}$) used for bone defect after operative traetment of benign bone tumors by clinical and radiological methods. Materials and Methods: DBM was used to treat bone defect after operative treatment of benign tumor from February 2012 to May 2013. Total 25 benign bone tumor cases (15 males, and 10 females) with mean age of 30.3 were studied. The diagnoses were solitary bone cyst in 9 cases, non ossifying fibroma in 5, fibrous dysplasia in 5, aneurysmal bone cyst in 3 and enchondroma in 3. In categorization by location of tumor, there were 5 cases of distal femur, 4 of proximal tibia, 3 of proximal femur, 3 of proximal humerus, 3 of phalanx, 2 of distal radius, 2 of hip bone, 2 of calcaneus, and 1 of scapula. Autogenous bone was used with DBM in 6 cases, and only DBM used in 19 cases. Mean periods of follow up were 8.7 months (range: 6 to 14 months). Amount of graft resorption and bone formation was observed with compare of post operation radiograph and the difference was shown by percentage. Resorption level was measured by DBM level which could be observed from simple x-ray, and bone formation level by bone trabecular formation level at impaired site. Results: Twenty three cases of total 25 cases showed bone union. In the 23 cases, more than 98% DBM resorption was observed after mean 4.3 months, and more than 98% bone formation was observed after mean 6.9 months. Lesser bone defect sizes showed faster bone formation and it was statistically significant (p=0.036). But other comparative studies on other factors such as, sex, age of patients and combination of autogenous bone were no statistically significant differences in graft resorption and bone formation. And there was no significant complication in periods of follow-up. Conclusion: Demineralized Bone Matrix (Genesis$^{(R)}$) is thought to be useful treatment for bone defect after operative treatment of benign bone tumor, however longer follow-up periods appears to be needed.

Assessment of Typhoon Trajectories and Synoptic Pattern Based on Probabilistic Cluster Analysis for the Typhoons Affecting the Korean Peninsula (확률론적 클러스터링 기법을 이용한 한반도 태풍경로 및 종관기후학적 분석)

  • Kim, Tae-Jeong;Kwon, Hyun-Han;Kim, Ki-Young
    • Journal of Korea Water Resources Association
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    • v.47 no.4
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    • pp.385-396
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    • 2014
  • Lately, more frequent typhoons cause extensive flood and wind damage throughout the summer season. In this respect, this study aims to develop a probabilistic clustering model that uses both typhoon genesis location and trajectories. The proposed model was applied to the 197 typhoon events that made landfall in the Korean peninsula from 1951 to 2012. We evaluate the performance of the proposed clustering model through a simulation study based on synthetic typhoon trajectories. The seven distinguished clusters for typhoons affecting Korean peninsula were identified. It was found that most of typhoon genesis originated from a remote position ($10^{\circ}{\sim}20^{\circ}N$, $120^{\circ}{\sim}150^{\circ}E$) near the Equator. Cluster, type B can be regarded as a major track due to the fact that its frequency is approximately about 25.4% out of 197 events and its direct association with strong positive rainfall anomalies.

Interdecadal Variation of Tropical Cyclone Genesis Frequency over the Western North Pacific (북서태평양에서 열대 저기압 발생빈도의 십년간 변동 특성)

  • Choi, Ki-Seon;Kim, Baek-Jo;Lee, Seong-Lo;Park, Jong-Kil
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.6
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    • pp.31-39
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    • 2009
  • This study has found that there is a reverse phase with interdecadal variation in temporal variations of tropical cyclone (TC) genesis frequency (TCGF) between Northwest sector and Southeast sector, based on climatological mean tropical cyclone genesis location over the western North Pacific. The TCGF in the Northwest sector has been increased since the mid 1980s (1986-2005), while TCGF in the Southeast sector was higher until the early 1970s (1951-1970). The analysis of a difference between 1986-2005 and 1951-1970 showed results as follows: i) Through the analysis of vertical wind shear (VWS) and sea surface temperature (SST), less VWS and higher SST in the former (latter) period was located in the Northwest (Southeast) sector. ii) In the analysis of TC passage frequency (TCPF), TCs occurred in the Northwest sector frequently passed from east sea of the Philippines, through East China Sea, to Korea and Japan in the latter period, while TCs in the former period frequently has a lot of influences on South China Sea (SCS). In the case of TCs occurred in the Southeast sector, TCs in the west (east), based on $150^{\circ}E$ had a high passage frequency in the latter (former) period. In particular, TCs during the latter period frequently moved toward from the east sea of the Philippines to SCS and southern China. iii) This difference of TCPF between the two periods was characterized by 500 hPa anomalous pressure pattern. Particularly, anomalous cyclonic circulation strengthened over the East Asian continent caused anomalous southerlies along the East Asian coast line from the east sea of the Philippines to be predominate. These anomalous winds served as steering flows that TC can easily move toward same regions.

Possible Relationship between NAO and Western North Pacific Typhoon Genesis Frequency (북대서양 진동과 북서태평양 태풍발생빈도와의 관계)

  • Choi, Ki-Seon;Park, Sangwook;Chang, Ki-Ho;Lee, Jong-Ho
    • Journal of the Korean earth science society
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    • v.34 no.3
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    • pp.224-234
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    • 2013
  • This study examined a strong positive correlation between the North Atlantic Oscillation (NAO) index during June and the total tropical cyclone (TC) genesis frequency in the western North Pacific during July and August. To investigate a possible cause for this relationship, the mean difference between the highest positive NAO years and the lowest negative NAO years was analyzed by dividing into when the El Ni$\tilde{n}$o and La Ni$\tilde{n}$a years were included and when the El Ni$\tilde{n}$o and La Ni$\tilde{n}$a years were not included. When the El Ni$\tilde{n}$o and La Ni$\tilde{n}$a years were included, for the positive NAO years, the TCs mostly occurred in the northwestern region of tropical and subtropical western Pacific, and showed a pattern that migrate from the sea northeast of the Philippines, pass the East China Sea, and move toward the mid-latitudes of East Asia. In contrast, for the negative NAO years, the TCs mostly occurred in the southeastern region of tropical and subtropical western Pacific, and showed a pattern that migrate westward from the sea southeast of the Philippines, pass the South China Sea, and move toward the southern coast of China and Indochinese peninsula. These two different TC migration patterns affect the recurving location of TC, and for the positive NAO years, the recurving of TC was averagely found to take place in the further northeast. In addition, the migration patterns also affect the TC intensity, and the TCs of positive NAO years had stronger intensity than the TCs of negative NAO years as sufficient energy can be absorbed from the ocean while moving north in the mid-latitudes of East Asia. The TCs of negative NAO years showed weak intensity as they get weaken or disappear shortly while landing on the southern coast of China and the Indochinese peninsula. On the other hand, the above result of analysis is also similarly observed when the El Ni$\tilde{n}$o and La Ni$\tilde{n}$a years were not included.

A Cartographic Study on the Earthly Paradise Represented in the Medieval Mappaemundi (서양 중세 세계지도에 표현된 지상낙원의 지도학적 연구)

  • Chul, Jung-In
    • Journal of the Korean Geographical Society
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    • v.43 no.3
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    • pp.412-431
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    • 2008
  • The achievements of the medieval mappaemundi should be evaluated on their own terms and in the context of their purpose. Medieval mappaemundi expressed christian world view which reflected Augustinian theology. These Christian world view and Greek and Roman classical geography were combined to form the cultural barkground of the medieval mappaemundi. These maps had a function to organize physical space according to religious principles. The Christian concept of the world as a temporal phenomenon, derived from the simultaneous creation of time and space as described in St. Augustin's theology was represented in these maps. The purpose of this paper is to consider geographic characteristics of earthly paradise expressed in medieval mappaemundi and their cartographic characteristics. For this, firstly, we reviewed medieval Christian scholars' opinions on earthly paradise. Secondly, centered on geographic location and representation method, we examined cartographic characteristics of medieval paradise mapping, Thirdly, we considered the shift of paradise according to chronological change. Fourthly, we examined the reason why earthly paradise disappeared from world map after fourteenth century.

Seasonal Predictability of Typhoon Activity Using an Atmospheric General Circulation Model and Observed Sea Surface Temperature Data (대기 대순환 모헝과 해수면 온도 관측 자료를 이용한 태풍 활동의 계절 예측 가능성)

  • Han, Ji-Young;Baik, Jong-Jin
    • Journal of the Korean earth science society
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    • v.27 no.6
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    • pp.653-658
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    • 2006
  • The seasonal predictability of typhoon activity over the western North Pacific is investigated using an atmospheric general circulation model GCPS. A ten-member ensemble with different initial conditions is integrated for five months using observed sea surface temperature data for each year from 1979 to 2003. It is shown that the monthly variation of occurrence frequency of simulated tropical storms and the distribution of tropical storm genesis location are similar to those of observed tropical storms, but the model is unable to reliably predict the interannual variation of the occurrence frequency of tropical storms. This is largely because the observed relationship between tropical storm occurrence frequency and ENSO is different from the simulated one. Unlike the observation, in which the tropical storm occurrence frequency has no relation to ENSO, the model has a tendency to generate more (less) tropical storms than normal during El Nino (La Nina). On the other hand, the interannual variation of the mean longitude of tropical storms that shows a close connection with ENSO in both observations and simulations is simulated similar to the observation.