• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4408-4425
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• 2023

Alarm flood due to abnormality propagation is the most difficult alarm overloading problem in nuclear power plants (NPPs). Root-cause analysis is suggested to help operators in understand emergency events and plant status. Multilevel Flow Modeling (MFM) has been extensively applied in alarm management by virtue of the capability of explaining causal dependencies among alarms. However, there has never been a technique that can identify the actual root cause for complex alarm situations. This paper presents an automated root-cause analysis system based on MFM. The causal reasoning algorithm is first applied to identify several possible root causes that can lead to massive alarms. A novel root-cause ranking algorithm can subsequently be used to isolate the most likely faults from the other root-cause candidates. The proposed method is validated on a pressurized water reactor (PWR) simulator at HAMMLAB. The results show that the actual root cause is accurately identified for every tested operating scenario. The automation of root-cause identification and ranking affords the opportunity of real-time alarm analysis. It is believed that the study can further improve the situation awareness of operators in the alarm flooding situation.

• 한국약용작물학회지
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• 제15권3호
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• pp.157-161
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• 2007

인삼 연작장해 원인과 경감대책을 수립하고자 2004년에는 2005년까지 작물과학원 증평시험지 연작토양에서 인삼 수확경 과년수와 예정지관리 유무에 따른 시험을 수행한 결과를 요약하면 다음과 같다. 인삼 연작지 수확경과년수가 짧을수록 생존율이 낮아지며 3${\sim}$4년 경과구 81${\sim}$95%의 뿌리썩음 이병주율을 보였다. 예정지 관리구는 미관리구보다 생존율이 다소 높으며 뿌리 썩음병 피해도 예정지 미관리와 같은 경향으로 예정지 관리효과는 크지 않다. 수확경과년수가 10년이상의 연작지에서도 연작장해를 일으키는 병원균 (C. destructans)이 분리되므로 재작 또는 연작시는 이점을 고려하여 재배지를 재선정하거나 예정지 토양관리대책을 수립해야 할 것으로 판단된다.

• 한국식생활문화학회지
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• 제26권6호
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• pp.734-742
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• 2011

This study was conducted to investigate the physicochemical characteristics of Eungi, which is used as a breakfast or health food. We manufactured lotus root starch and Eungi by a traditional method and discovered that the viscosity of Eungi with 4-5% starch content was similar to fermented milk. When the physicochemical properties and sensory acceptability of a Eungi beverage combined with different amounts (0.5, 1.0, 1.5, and 2.0%) of lotus root starch were investigated, consumer acceptability was highest with Eungi combined with 0.5% starch and 6% sugar. When the physicochemical properties and sensory acceptability of Eungi beverage combined with different extract bases were investigated, the acceptability of taste and texture was highest with purple sweet potato extract and the acceptability of color was highest with omija extracts.

• 대한소아치과학회지
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• 제21권2호
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• pp.518-524
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• 1994

A traumatically intruded tooth is one that is forcefully and abruptly dispaced from its position into the surrounding alveolar bone. Although intrusion of permanent teeth is infrequent, the sequelae compromise the longevity of the tooth and often include pulp necrosis, internal and external root resorption, rupture of periodontal ligament and loss of marginal bone. The purpose of this study was to examine three common management techniques for traumatic intrusion, observation for re-eruption, surgical repositioning & fixation and orthodontic extrusion. In the recent, the accepted treatment was to allow the permanent teeth to reerupt spontaneously for 6-8 weeks. If this did not occur, orthodontic traction was applied. The pulpal status of the teeth was monitored and either calcium hydroxide therapy or conventional endodontics was instituted following pulpal necrosis depending on the maturity of the root end. Pulpectomy and a calcium hydroxide filling were also the treatment of choice if there was evidence of internal or external root resorption. This will reduce the chance of root resorption and provide a period of monitoring prior to a definitive root canal filling.

• Restorative Dentistry and Endodontics
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• 제37권3호
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• pp.180-184
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• 2012

Traumatic injuries of the face often involve root fractures especially in anterior teeth. The prognosis and the treatment of the root fracture depend on the extent of the fracture line, general health and patient compliance. This case report outlines a new conservative trial treatment modality to stabilize the maxillary central incisors with horizontal root fracture on the cervical to middle third by fabricating canine guidance to remove loading on the traumatized maxillary central incisors during eccentric movements and thus inducing spontaneous healing of the fractured line between the fragments. Radiographs after thirty months showed adequate healing with no signs of pathological changes including root resorption, ankylosis or displacement. Long term follow-up revealed that vitality, stability and aesthetics were maintained and the patient was satisfied with the outcome.

• Journal of Information Technology Applications and Management
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• 제24권4호
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• pp.71-92
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• 2017

Finding a root cause is an essential step to solving a complex problem. Some previous studies have used the Delphi method for gathering opinions about root causes from geographically dispersed experts. However, we assert that complicated problems such as an industry ecosystem would make a general type of the Delphi method less practical because of too much psychological burden on study participants. In this study we present a preliminary list-based Delphi study method for identifying a root cause. This method was used to identify a root cause and draw a causal map for the information industry ecosystem problems.

• 대한치과의사협회지
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• 제58권8호
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• pp.486-494
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• 2020

Objectives: Management of a horizontal root fracture of an anterior teeth is challenging and often requires multiple approaches for improving the functional and esthetic outcomes. This case report describes the treatment and 2-yr follow up of 3 maxillary incisors with horizontal root fracture. Two maxillary central incisors were treated with Mineral Trioxide Aggregate (ProRoot MTA, Dentsply, Tulsa, OK, USA). Left maxillary lateral incisors were treated with endodontic treatment and submerged. During 2-yr of follow-up evaluation, the root-fractured teeth of the present patients were well retained in the arch, showing periodontal healing even after endodontic treatment.

• Restorative Dentistry and Endodontics
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• 제39권2호
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• pp.126-131
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• 2014

Among dental traumas, horizontal root fractures are relatively uncommon injuries. Proper initial management and periodical evaluation is essential for the successful treatment of a root-fractured tooth. If pulpal necrosis develops, endodontic treatment is indicated, exclusively for the coronal fragment. Fragment diastases exert a great influence on healing at the fracture line and on pulpal necrosis. An adequately treated root-fractured tooth has a good prognosis. This case report describes the treatment and 2-yr follow up of 3 maxillary central incisors, first with horizontal root fracture, second with horizontal root fracture and avulsion, and third with horizontal root fracture and lateral luxation. All three cases were treated with mineral trioxide aggregate (ProRoot, Dentsply). During 2 yr of follow-up evaluation, the root-fractured teeth of the present patients were well retained in the arch, showing periodontal healing, even after endodontic treatment.

• Restorative Dentistry and Endodontics
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• 제40권1호
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• pp.79-84
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• 2015

This case report presents surgical endodontic management outcomes of maxillary incisors that were infected via the lateral canals. Two cases are presented in which endodontically-treated maxillary central incisors had sustained lateral canal infections. A surgical endodontic treatment was performed on both teeth. Flap elevation revealed vertical bone destruction along the root surface and infected lateral canals, and microscopy revealed that the lateral canals were the origin of the lesions. After the infected lateral canals were surgically managed, both teeth were asymptomatic and labial fistulas were resolved. There were no clinical or radiographic signs of surgical endodontic management failure at follow-up visits. This case report highlights the clinical significance and surgical endodontic management of infected lateral canal of maxillary incisor. It is important to be aware of root canal anatomy variability in maxillary incisors. Maxillary central incisors infected via the lateral canal can be successfully managed by surgical endodontic treatment.

• 한국산학기술학회논문지
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• 제5권1호
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• pp.7-12
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• 2004

급액관리에 관련된 단계를 4단계로 나누었으며, 각 단계별 수분 이동 저항을 규명하고, 단계 중에서 급액 상황에 따라 관련 인자의 priority를 설정함으로써 펄라이트 자루재배할 경우 율속인자 중심의 적정 급액관리 기준을 제안하였다. 특히, 급액관리의 가장 중요한 율속인자인 뿌리까지의 수분도달거리를 최소한으로 하여 필요한 수분을 공급하는 과정과 역사성을 부여한 뿌리발달 조장이 가장 중요한 것으로 판명되었다.