• 터널과지하공간
• /
• 제16권6호
• /
• pp.451-466
• /
• 2006

DOM 시추코어에서 측정된 불연속면의 위치 및 방향성 자료를 이용하여 현장암반의 구조적 특성을 고려한 사면거동 해석이 가능하였다. 3차원 공간에서 설정된 절리들의 위치에 의거하여 붕락 현상이 발생된 개착사면의 추가적인 파괴양상을 예측하였으며, 개별 절리면의 붕락위해 가능성과 개착면 상에서의 trace 위치를 파악하여 세부적인 사면거동 양상을 파악하였다. 개착사면 횡단면에서 개별절리들의 파괴거동 양상과 사면체 블록형성을 대수학적으로 산출하여 사면 붕락심도를 규명하였다. 현장사면에 자동화 계측시스템을 설치하여 사면 거동에 대한 계측자료를 수집하였으며, DOM 시추공 내에 지중경사계를 설치하여 사면거동 양상을 횡단면 해석 결과와 대비시켜 분석하였다. 지중경사계를 이용하여 측정된 개착면의 표면변위 자료에 의거하여 사면 파괴시기를 예측할 수 있는 방법론을 고찰하였으며, 강우가 사면거동에 끼치는 영향성을 분석하였다.

• 한국언론정보학보
• /
• 제51권
• /
• pp.65-86
• /
• 2010

신문왕국이라 불리는 일본 신문 역시 발행부수, 매출액, 광고수익 등에서 위기를 맞고 있다. 이에 일본의 주요 전국지 경영진들은 현재 일본 신문이 직면한 위기의 원인을 어떻게 진단하고 있고, 나아가 위기를 극복하기 위해 어떠한 대응전략을 펴고 있는지를 심층인터뷰와 2차 자료를 통해 살펴보았다. 일본 주요 신문사의 경영진들은 위기 원인을 주로 매체환경 변화에 따른 젊은 독자의 감소와 같은 외적 요인에서 찾고 있었다. 또한 광고매체로서 신문의 매력도 감소나 제작유통비용 상승과 같은 신문산업의 구조적 요인을 문제로 꼽았다. 위기에 대처하기 위한 대응으로는 젊은 독자에게 어필할 수 있도록 신문의 지면 강화, 온라인-오프라인 패키지 광고와 고객맞춤형 광고 시도, 온라인, 모바일 영역으로의 뉴스유통 확대, 부동산 사업 등 다각화를 통한 재정 안정성 확보, 브랜드 가치를 높이기 위한 각종 사업, 신문사간 공동 뉴스사이트 운영, 공동인쇄와 배달 등 다양한 협업을 시도하고 있다. 본 논문은 일본 신문사 경영진들의 위기인식에서부터 극복을 위한 다양한 대응전략을 통해 국내 신문기업들이 공유할만한 정보와 전략들을 제시했다는 데 의의가 있다.

• 한국보육학회지
• /
• 제17권1호
• /
• pp.1-28
• /
• 2017

본 연구는 보육교사들이 반응성 상호작용 전략을 적용을 한 후 영아의 중심축 행동의 발달이 어떠한지 살펴본 사례연구이다. 연구 참여자는 H재단에서 수탁 운영하는 직장어린이집 5곳의 만1세 영아 5명과 그들의 담임교사 5명이다. 이 연구에서는 교사-영아 상호작용을 녹화한 동영상, 일화기록, 교사의 반성적 저널, 교사와의 심층면담 자료를 통해 연구대상 영아의 중심축 행동 변화를 분석하였다. 연구결과를 살펴보면 보육교사의 반응성 상호작용 전략 적용은 영아의 중심축 행동(주의집중, 문제해결, 흥미, 협력, 주도성, 공동주의, 애정)을 긍정적으로 변화시켰다. 이러한 연구결과는 영아를 담당하고 있는 보육교사들이 영아의 중심축 행동 발달을 돕기 위해 반응성 상호작용의 중요성을 인식하고 실천해야 함을 시사한다.

• 해양환경안전학회지
• /
• 제8권2호
• /
• pp.71-78
• /
• 2002

For the first Maritime Accident Inquiry System in Korea, Central Marine Accidents Inquiry Committee were founded in Seoul and District Marine Accidents Inquiry Committee in Busan city In 1963 to determine the circumstances of the accidents and causes. At the present day, it was settled as Maritime Safety Tribunal tough several revision of the Law and regulations regarding the Maritime Accident Inquiry System. In Korea, there occurred about m cases of marine accident, and as a result, about 200 people were lost human lives in average per year. In accordance with the change of circumstances such as traffic increasing and being bigger in size, being faster in speed, etc., the causes of the marine accidents become complicated year by year. Accordingly, in this moment, it is meaningful that the introduction of the Research Official who assists the Judges probing the cases fair and square. In this Paper, with the consideration of the several kinds of Research Official System, such as the Research Official of the Korean Supreme Court, the Supreme Public Prosecutors' Office and the Constitutional Court, Japanese Supreme Court, Law Clerk in USA, etc., the selection, numbers, duty of the Research Official were studied. The results of the study are as follows; 1. The Research Official to be appointed among the person having long enough career as a Judge, Investigator engaged in the Maritime Safety Tribunal due to he sho띨d have capability to confirm perfectly logical judgement and to collect enough material for the conclusion of the causes of the case. The one who understands the foreign language is preferred for the study of the foreign cases; 2. It will be logical to post 3 joint Research Officials in Korea Maritime Safety Tribunal in Seoul after due consideration the cases treated a year; 3. It will be logical for the Research Official to perform the collection of material and inspection of the scene for the trial and inquiry of the cases, to attend the cases filed suit to the Supreme Court, to make commentarial papers regarding the judged cases, to collect statistics of marine accidents and to devise a reform measure through in-depth analysis of the accidents frequently occurred, to study for the improvement of the Maritime Accident Inquiry System;

• Advances in aircraft and spacecraft science
• /
• 제2권2호
• /
• pp.125-168
• /
• 2015

Dynamic aeroelastic behavior of structurally nonlinear Joined Wings is presented. Three configurations, two characterized by a different location of the joint and one presenting a direct connection between the two wings (SensorCraft-like layout) are investigated. The snap-divergence is studied from a dynamic perspective in order to assess the real response of the configuration. The investigations also focus on the flutter occurrence (critical state) and postcritical phenomena. Limit Cycle Oscillations (LCOs) are observed, possibly followed by a loss of periodicity of the solution as speed is further increased. In some cases, it is also possible to ascertain the presence of period doubling (flip-) bifurcations. Differences between flutter (Hopf's bifurcation) speed evaluated with linear and nonlinear analyses are discussed in depth in order to understand if a linear (and thus computationally less intense) representation provides an acceptable estimate of the instability properties. Both frequency- and time-domain approaches are compared. Moreover, aerodynamic solvers based on the potential flow are critically examined. In particular, it is assessed in what measure more sophisticated aerodynamic and interface models impact the aeroelastic predictions. When the use of the tools gives different results, a physical interpretation of the leading mechanism generating the mismatch is provided. In particular, for PrandtlPlane-like configurations the aeroelastic response is very sensitive to the wake's shape. As a consequence, it is suggested that a more sophisticate modeling of the wake positively impacts the reliability of aerodynamic and aeroelastic analysis. For SensorCraft-like configurations some LCOs are characterized by a non-synchronous motion of the inner and outer portion of the lower wing: the wing's tip exhibits a small oscillation during the descending or ascending phase, whereas the mid-span station describes a sinusoidal-like trajectory in the time-domain.

• Steel and Composite Structures
• /
• 제27권3호
• /
• pp.337-353
• /
• 2018

In previous weak-axis moment connection tests, brittle fracture always initiated near the edge of the beam flange groove weld due to force flow towards the stiffer column flanges, which is the opposite pattern as strong-axis moment connections. As part of the China NSFC (51278061) study, this paper tested two full-scale novel weak-axis reduced beam section moment connections, including one exterior frame connection specimen SJ-1 under beam end monotonic loading and one interior frame joint specimen SJ-2 under column top cyclic loading. Test results showed that these two specimens were able to satisfy the demands of FEMA-267 (1995) or ANSI/AISC 341-10 (2010) without experiencing brittle fracture. A parametric analysis using the finite element software ABAQUS was carried out to better understand the cyclic performance of the novel weak-axis reduced beam section moment connections, and the influence of the distance between skin plate and reduced beam section, a, the length of the reduced beam section, b, and the cutting depth of the reduced beam section, c, on the cyclic performance was analyzed. It was found that increasing three parametric values reasonably is beneficial to forming beam plastic hinges, and increasing the parameter a is conducive to reducing stress concentration of beam flange groove welds while increasing the parameters b and c can only reduce the peak stress of beam flange groove welds. The rules recommended by FEMA350 (2000) are suitable for designing the proposed weak-axis RBS moment connection, and a proven calculation formulation is given to determine the thickness of skin plate, the key components in the proposed weak-axis connections. Based on the experimental and numerical results, a design procedure for the proposed weak-axis RBS moment connections was developed.

• 농업과학연구
• /
• 제47권1호
• /
• pp.163-171
• /
• 2020

In this study, a large laboratory model experiment was conducted with the aim of developing an embankment reinforcement method to prevent overtopping, which is the main cause for the failure of agricultural reservoirs. The model experiment was carried out with concrete and asphalt as a permanent reinforcement method and with geomembrane as the emergency method at a deteriorated homogeneous reservoir. Under the non-reinforced conditions, the pattern of the failure appeared in several scour directions from the downstream slope as the overtopping began, and the width and depth of the erosion were magnified as it gradually moved to the dam crest. Under the conditions reinforced with asphalt and concrete, the overtopping was stabilized. In the case of the concrete reinforcement, it was found that the slope of the riprap boundary exhibited downward erosion by the current; thus, it was necessary to construct an extension up to the riprap joint of the upstream and downstream sides to prevent the expansion of the failure. Under the conditions reinforced with the geomembrane sheet, the overtopping was stabilized, and no seepage was found that required the emergency reinforcement method. Asphalt, concrete, and geomembrane sheet reinforcements have been shown to be capable of delaying failure for about 1 hour and 40 minutes compared to the non-reinforcement conditions. The reinforcement method is considered to be a very effective method to prevent disasters during overtopping. The pore water pressure can be used as useful data to predict the risk of failure at an embankment.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 추계학술대회 논문집
• /
• pp.587-589
• /
• 2009

The districts of underground geologic structure in Jeju island where underground air is distributed are lava cave, pyroclastic, open joint, and crushing zone. Such districts are identified to secure an enough airflow when air ventilation layer is to secure 25-35m in depth. In Jeju, Ground air is used for heating greenhouse and fertilizing natural $CO_2$ gas by suppling directly into greenhouse. But the heating method by suppling ground air into greenhouse directly bring about several problem. The occurrence of disease of the crops by high humidity is worried because the underground air which becomes discharge from underground air layer has over 90% relative humidity. The underground air is inadequate in heating for crops which need high temperature heating such as mangos, Hallbong and mandarin orange because the temperature of it is $15{\sim}18^{\circ}C$. Also There is worry where the ventilation loss becomes larger because the air pressure inside greenhouse is high by supplying underground air directly. In this study the heat pump system using underground air as heat source was developed and heating performance of the system was analysed. Heating COP of the system was 2.5~5.0 and rejecting heat into greenhouse and extracting heat from underground air were 40,000~27,000 kcal/h, 30,000~18,000 kcal/h respectively.

• 대한골관절종양학회지
• /
• 제3권2호
• /
• pp.89-97
• /
• 1997

Twenty hundred and five out of 266 patients who were registered in Korea Cancer Center Hospital from Mar. 1985 to Jan. 1994, were analyzed in the aspect of survival and local recurrence. Fifty one patients were excluded due to inadequate data and follow up. Prognostic factors for survival were evaluated statistically. One hundred and four cases were male, 101 female. Average age was 39.7(range 1 to 77) year with a peak incidence around 4th decade. The most frequent diagnosis was malignant fibrous histiocytoma(MFH)(24.1%). Liposarcoma, synovial sarcoma, rhabdomyosarcoma, malignant peripheral nerve sheath tumor and fibrosarcoma were relatively common diagnostic entities, in decreasing order. In location, extremity was 179(87.3%) and trunk 26(12.7%). Average follow up period was 7.5 years(6 months to 10 years). Actuarial 5 years and 10 years survival rate were 64.0% and 40.8% respectively. In univariate analysis with log-lank test, significant differences in survival rate were noted in histopathological diagnosis, size(10 cm), stage and metastasis. Age, sex, tumor location, tumor depth and local recurrence didn't affect the survival rate. Adjuvant chemotherapy and/or radiotherapy did not affect overall survival rate, but lowered the local recurrence rate when compared with surgery only. Surgical margin did not affect the survival rate, but local recurrence rate was different according to each margin; 5.7% in more than wide; 39.5% in marginal; and 60.0% in intralesional excision. In multivariate analysis for results of univariate analysis with Cox's propotional model, metastasis was a meaningful factor for survival of soft tissue sarcoma.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 하계학술대회 논문집 G
• /
• pp.2518-2520
• /
• 1998

Silicon can be reactive ion etched (RIE) either isotropically or anisotropically. In this paper, a new micromachining technology combining these two etching characteristics is proposed. In the proposed method, the fabrication steps are as follows. First. a polysilicon layer, which is used as the bottom electrode, is deposited on the silicon wafer and patterned. Then the silicon substrate is etched anisotropically to a few micrometer depth that forms a cavity. Then an PECVD oxide layer is deposited to passivate the cavity side walls. The oxide layers at the top and bottom faces are removed while the passivation layers of the side walls are left. Then the substrate is etched again but in an isotropic etch condition to form a round trench with a larger radius than the anisotropic cavity. Then a sacrificial PECVD oxide layer is deposited and patterned. Then a polysilicon structural layer is deposited and patterned. This polysilicon layer forms a pivot structure of a rocker-arm. Finally, oxide sacrificial layers are etched away. This new micromachining technology is quite simpler than conventional method to fabricate joint structures, and the devices that are fabricated using this technology do not require a flexing structure for motion.