• Journal of the Korean GEO-environmental Society
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• v.24 no.8
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• pp.13-20
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• 2023

Tunnelling through the geological anomalies has widely known to have many difficulties such as bottom heave, crack of lining, squeezing and so on. To stabilize the tunnel during the construction or after construction, various reinforcing methods have been introduced and applied such as micropiling at the bottom of tunnel to prevent the bottom heave. In this study, long-term behavior of tunnel in the presence of geological anomalies was predicted using numerical analyses. To this end, material properties for swelling rock model capable of representing the rock swelling behavior was obtained using matching process with measured data to validate the adopted model. After the model validation, simulations were performed to predict the long-term behavior of tunnel in the geological anomalies.

• The Transactions of the Korea Information Processing Society
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• v.13 no.3
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• pp.130-139
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• 2024

Artificial intelligence models are being used to detect facility anomalies using physics data such as vibration, current, and temperature for predictive maintenance in the manufacturing industry. Since the types of facility anomalies, such as facility defects and failures, anomaly detection methods using autoencoder-based unsupervised learning models have been mainly applied. Normal or abnormal facility conditions can be effectively classified using the reconstruction error of the autoencoder, but there is a limit to identifying facility anomalies specifically. When facility anomalies such as unbalance, misalignment, and looseness occur, the facility vibration frequency shows a pattern different from the normal state in a specific frequency range. This paper presents an N-segmentation anomaly detection method that performs anomaly detection by dividing the entire vibration frequency range into N regions. Experiments on nine kinds of anomaly data with different frequencies and amplitudes using vibration data from a compressor showed better performance when N-segmentation was applied. The proposed method helps materialize them after detecting facility anomalies.

• Journal of Climate Change Research
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• v.34 no.16
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• pp.6841-6853
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• 2021

The leading modes of the North Pacific jet (NPJ) variability include intensity changes and meridional shifts in jet position on low-frequency time scales. These leading modes of NPJ variability are closely associated with weather and climate conditions spanning from Asia to the United States. In this study, we investigated changes in the NPJ's role as a conduit for U.S. surface air temperature (SAT) anomalies during the boreal winter across the late 1990s. We found that the leading mode of NPJ variability changed from the NPJ intensity changes to meridional shifts in NPJ position across the late 1990s. It leads to the change in the role of the NPJ as a conduit for U.S. SAT anomalies. Before the late 1990s, the variability of NPJ intensity significantly impacted western U.S. SAT anomalies related to the anomalous surface cyclonic circulation over the North Pacific. After the late 1990s, however, the variability of the NPJ's meridional shift significantly influenced the eastern U.S. SAT anomalies in association with the anomalous surface cyclonic circulation over the northern North Pacific. Further analysis and model experiments revealed that the western to central North Pacific Ocean has been warming since the late 1990s and modulates atmospheric baroclinicity. This phenomenon mainly leads to a northward NPJ shift and implies that the eddy-driven mechanism on the NPJ's formation, which acts to enhance the meridional variability of NPJ position, becomes dominant. We conclude that this northward shift of NPJ could have contributed to enhancing the NPJ's meridional shift variability, significantly influencing the eastern U.S. SAT anomalies since the late 1990s.

• Journal of the Korean Geophysical Society
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• v.2 no.1
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• pp.27-38
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• 1999

The errors between track segments or at the cross-over points of shipborne gravity were successfully reduced by applying a cross-over error adjustment technique using satellite gravity. The integration of shipborne and satellite altimeter-implied free-air gravity anomalies after the cross-over error adjustment resulted in a high resolution gravity map which contains both short and long wavelength components. The successful adjustment of the cross-over errors in the shipborne gravity using the satellite gravity suggests that the shipborne gravity can be combined with the satellite anomalies characterized by a stable and long wavelength component. The resulting free-air anomaly map is evenly harmonized with both short and long wavelength anomalies. Thus the corrected anomaly map can be better used for the geological interpretation. Free-air anomalies with more than 140 mGal in total variations generally correspond to the seafloor topographic changes in their regional patterns. A series of gravity highs are aligned from the Korea Plateau to the Oki Island, which are interpreted to be caused by seamounts or volcanic topographies. The gravity minima along the western and southern shelf edge are associated not only with the local basement morphology and thick sediment fill at the continental margin, but also possibly with the crustal edge effect known for passive continental margins. Series of NE-trending linear anomalies are possibly caused by a swarm of volcanic intrusions followed the initial opening of the Ulleung Basin. The linear high anomalies in the Ulleung Plateau are terminated by the straightly NNW-trending anomalies with a sharp gradient in its western boundary which indicates a fault-line scarp. The opposite side adjoined with the fault-line scarp shows no correlation with the fault-line scarp in geometry indicating that the block might be horizontally slided from the north. A gravity high in contrast to the deepening in seafloor toward the northeastern central Ulleung Basin is probably responsible for the thin crust and shallow seated mantle. The gravity minima along the western and southern shelf edge are associated not only with the local basement morphology and thick sediment fill at the continental margin, but also possibly with the crustal edge effect known for passive continental margins. Series of NE-trending linear anomalies are possibly caused by a swarm of volcanic intrusions followed the initial opening of the Ulleung Basin. The linear high anomalies in the Ulleung Plateau are terminated by the straightly NNW-trending anomalies with a sharp gradient in its western boundary which indicates a fault-line scarp. The opposite side adjoined with the fault-line scarp shows no correlation with the fault-line scarp in geometry indicating that the block might be horizontally slided from the north. A gravity high in contrast to the deepening in seafloor toward the northeastern central Ulleung Basin is probably suggestive of a thin crust and shallow seated mantle.

• Journal of the Korean association of regional geographers
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• v.4 no.1
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• pp.43-56
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• 1998

The purpose of this study is to identify distributional characteristics of climatic elements and to analyze synoptic characteristics on the pressure fields for spring droughts in Korea. In the distributions of minimum temperature during the spring droughts, positive anomalies and negative anomalies are mixed up, but in March the negative anomaly areas are widely distributed in Korea. It implies that the droughts of March have more frequent occurrences of the west-high, east-low pressure patterns. In the maximum air temperatures, the positive anomalies appear in Korea. It indicates that the spring droughts have rain days, cloud amount and humidities less than normal. As a result, the amount of evaporation is increased in Korea. In the pressure anomaly of surface pressure fields, the positive anomalies appear in the west, negative anomalies in the east in March, but in May the positive anomalies appeared zonally around the Korean peninsula. It indicates that March droughts have more frequent occurrences of the west-high. east-low patterns, but in May the Korean Peninsula has more frequent recurrences of the migratory anticyclone patterns. The height anomaly patterns of 500hPa pressure surface in spring droughts are similarly shown to those of surface fields. In March droughts, the positive height anomalies appear in the west, the negative height anomalies in the east, but in April the negative height anomaly areas are extended to the west part. In May the positive anomalies appear zonally around the Korean Peninsula, and strong positive height anomalies appear around the Kamchatka Peninsula and the sea of Okhotsk. These are the result of circulations that inhibit the eastward movement of westerlies and that has persistent anticyclone circulation patterns around the Korean Peninsula. As a result, the zonal indices of westerlies during March and April droughts are lower than normal, but higher in May. These data indicate that early spring droughts are associated with weak zonal flow, but the late spring droughts are obviously related with strong zonal flow. In addition, during early spring droughts the abnormally deep trough over the west coast of the North Pacific Ocean that accompanied the anticyclone was associated with frequent advection of air from the dry regions in the Central Asia into the Korean Peninsula. The atmospheric circulation patterns at the height of the 500hPa pressure surface in May was quite different from March and April circulation patterns. Instead of the abnormal ridge in the west and trough in the east, the circulation pattern in May was characterized by a much stronger than normal anticyclone over the Korean Peninsula. Also, the zonal indices of westerlies in May are higher than normal. The occurrences of drought in early spring, therefore, have mechanism different from those of late spring.

• Journal of Chest Surgery
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• v.13 no.4
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• pp.414-417
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• 1980

During the period from 1958 to July 31, 1980, there were 1764 Cardiovascular Surgical cases consisting of 1166 congenital and 598 acquired lesions in the Department of Cardiothoracic Surgery, Seoul National University Hospital. For 1764 cases 1162 open heart surgery and 602 conventional operations were performed. Among 1166, congenital lesions 266 adult cases were found. Adult cases occupy 15.1% of the total cases consisting of 24.5% of acyanotic and 19.9% of cyanotic group. Over all operative mortality of adult cases was 6.8% compared with 12.4% of total cases. Left over congenital cardiovascular anomalies in Korea can be safely operated at the present time. The oldest operated patient among adult congenital cardiovascular anomalies was 57 years old female atrial septal defect case. For 1162 cases open heart surgery bubble oxygenators were utilized except 2 membrane oxygenators. Various kinds of bubble oxygenators have been used but recently Shiley**** oxygenators are being used exclusively with satisfactory results.

• Childhood Kidney Diseases
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• v.22 no.1
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• pp.12-16
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• 2018

Herlyn-Werner-Wunderlich (HWW) syndrome is a rare congenital malformation syndrome that is characterized by a triad of uterine didelphys, blind hemivagina, and ipsilateral renal agenesis. There is a wide variety of phenotypic presentation which is recognized as a spectrum of disease rather than a separate entity. The exact incidence and pathogenesis of HWW syndrome are yet to be investigated. While this disease typically involves adolescent girls who present with abdominal pain or a pelvic mass that is secondary to hematocolpos, nowadays, a majority of potential patients with HWW are being prenatally screened for renal anomalies. Therefore, it is recommended to search for uterovaginal anomalies whenever a multicystic dysplastic kidney or the absence of a kidney is noted in a newborn female, and the role of pediatric nephrologists has become ever more important for early recognition of the disease.

• Korean Journal of Head & Neck Oncology
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• v.12 no.1
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• pp.22-25
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• 1996

A very important and interesting problem occasionally seen in the neck of children and adults is a branchial cleft anomaly. It is a rare congenital neck disease and presents a painless palpable mass of neck in most cases. We have retrospectively reviewed the medical records of 28 patients operated upon for branchial cleft anomaly at Department of Surgery, Chonnam University Hospital between January, 1991 and December, 1995. Three of these lesions were considered to have originated from the first branchial cleft, and 25 from the second branchial cleft. Females are about twice more common than male patients. Pathological findings showed the cysts were lined squamous epithelium and subepithelial lymphoid follicles in most cases. Five out of 28 patients with branchial cleft anomalies had previous incision procedures. All patients after complete removal of branchial anomalies have no recurrences.

• ETRI Journal
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• v.32 no.5
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• pp.687-694
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• 2010

Breaks in presence (BIP) are those moments during virtual environment (VE) exposure in which participants become aware of their real world setting and their sense of presence in the VE becomes disrupted. In this study, we investigate participants' experience when they encounter technical anomalies during game play. We induced four technical anomalies and compared the BIP responses of a navigation mode game to that of a combat mode game. In our analysis, we applied a linear mixed model (LMM) and compared the results with those of a conventional regression model. Results indicate that participants felt varied levels of impact and recovery when experiencing the various technical anomalies. The impact of BIPs was clearly affected by the game mode, whereas recovery appears to be independent of game mode. The results obtained using the LMM did not differ significantly from those obtained using the general regression model; however, it was shown that treatment effects could be improved by consideration of random effects in the regression model.

• Journal of Chest Surgery
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• v.17 no.4
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• pp.632-635
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• 1984

Hypoplastic RV was rarely combined with various other intracardiac anomalies. We experienced the excellent result after surgical correction in these 2 patients. 1. F/7: Combined anomalies were, [1] Hypoplastic Rt. Coronary art.[2] Hypoplastic RV [3] ASD [secundum] & [4] PS [infundibular & valvular] After CP Bypass, [1] Direct suture of ASD [2] Infundibulectomy [3] Pul valvulotomy & [4] Patch enlargement of RVOT with Pericardial monocusp were done 2. F/14: Combined anomalies were, [1] Hypoplastic RV [2] P5 [infundibular] [3] T5 [4] VSD [Type II] [5] ASD [secundum] & [6] 2\ulcornerA-V Block fter CP Bypass, [1] Infundibulectomy [2] Tricuspid valvulotomy [3] Patch repair of VSD & ASD & [4] Implantation of permanent pacemaker were done. Above operations resulted in marked improvement with disappearance of cyanosis & dyspnea.