Failure patterns of repairable systems and a flexible intensity function model

Jiang, R.,Huang, C. The Korean Reliability Society 2012 International Journal of Reliability and Applicati Vol.13 No.2

Engineering systems are usually repairable. The reliability of a repairable system can be represented by failure intensity function. A type of shape of failure intensity function is called a failure pattern. Reliability-Centred Maintenance (RCM) presents six typical failure patterns but its definition is unclear. It is an open issue how to recognize the failure pattern of repairable systems. This paper first discusses the problems of RCM with the notion of failure pattern; then presents the method for failure pattern recognition; and finally proposes a flexible failure intensity function model. The appropriateness of the model is illustrated by a real-world example.

Clinical factors related to recurrence after hepatic arterial concurrent chemoradiotherapy for advanced but liver-confined hepatocellular carcinoma

Cha, Hyejung,Yoon, Hong In,Lee, Ik Jae,Koom, Woong Sub,Han, Kwang-Hyub,Seong, Jinsil Oxford University Press 2013 Journal of radiation research Vol.54 No.6

<P>Before the sorafenib era, advanced but liver-confined hepatocellular carcinoma (HCC) was treated by liver-directed therapy. Hepatic arterial concurrent chemoradiotherapy (CCRT) has been performed in our group, giving substantial local control but frequent failure. The aim of this study was to analyze patterns of failure and find out predictive clinical factors in HCC treated with a liver-directed therapy, CCRT. A retrospective analysis was done for 138 HCC patients treated with CCRT between May 2001 and November 2009. Protocol-based CCRT was performed with local radiotherapy (RT) and concurrent 5-fluorouracil (5-FU) hepatic arterial infusion chemotherapy (HAIC), followed by monthly HAIC (5-FU and cisplatin). Patterns of failure were categorized into three groups: infield, intrahepatic-outfield and extrahepatic failure. Treatment failure occurred in 34.0% of patients at 3 months after RT. Infield, intrahepatic-outfield and extrahepatic failure were observed in 12 (8.6%), 26 (18.7%) and 27 (19.6%) patients, respectively. Median progression-free survival for infield, outfield and extrahepatic failure was 22.4, 18 and 21.5 months, respectively. For infield failure, a history of pre-CCRT treatment was a significant factor (<I>P</I> = 0.020). Pre-CCRT levels of alpha-fetoprotein and prothrombin induced by vitamin K absence or antagonist-II were significant factors for extrahepatic failure (<I>P</I> = 0.029). Treatment failures after CCRT were frequent in HCC patients, and were more commonly intrahepatic-outfield and extrahepatic failures than infield failure. A history of pre-CCRT treatment and levels of pre-CCRT tumor markers were identified as risk factors that could predict treatment failure. More intensified treatment is required for patients presenting risk factors.</P>

Failure Pattern of Singe-layer Reticulated Dome under Severe Earthquake and Its Shaking Table Test

Gui-Bo Nie,Xudong Zhi,Feng Fan,Jun-Wu Dai 한국강구조학회 2014 International Journal of Steel Structures Vol.14 No.2

Based on the constitutive model with considering material damage accumulation, the influence of material damageaccumulation on the responses of the structure is investigated in detail through the incremental dynamic analysis method (IDAanalysis). The failure pattern of single-layer reticulated dome under dynamic loading is obtained using IDA analysis throughmultiple sets of seismic load records and harmonic loading, which is identified to be the dynamic instability failure caused bythe geometric nonlinearity and the dynamic strength failure resulted by the material nonlinearity. The shaking table tests ofsingle-layer reticulated dome are exploited to verify the failure pattern of the structure under seismic load records. Experimentalresults show that the plasticity of the model develops and the deformation increases, as well as the mechanical propertiesweakens continuously with the increasing of the loading value, which indicates that the failure pattern of the structure isdynamic strength failure.

The Causes of Pragmatic Failure from the Perspective of Bilingualism and its Implications for Foreign Language Teaching

Shaoxia Liu,강문구 사단법인 미래융합기술연구학회 2021 아시아태평양융합연구교류논문지 Vol.7 No.1

Pragmatics theory began to be studied and developed in China in the 1980s and 1990s. Among the various branches and concepts of pragmatics, pragmatic failure is an important aspect that cannot be ignored. In recent decades, there has been a variety of developments in the field of pragmatics. Many studies use the method of contrastive analysis to summarize the types of failures in communication between English and Chinese users. In addition to linguistic pragmatic failures, there are also social pragmatic failures and even non-verbal pragmatic failures. Most of these types of failures focus on the fact that Chinese students are the initiators of pragmatic failures. However, with the development of internationalization and the emergence of “Chinese fever”, more and more Westerners will also produce pragmatic failures in the process of using Chinese, which will lead to the failure of communication as well. The first part of this paper analyzes the research background by using the method of literature analysis, pointing out the direction of pragmatic research in China, such as various discourse acts, adaptation theory, pragmatic failure in translation aspects. The second part uses the contrastive study method based on the phenomenon to compare the main causes of pragmatic failure. The causes are the differences in culture, thinking pattern and lacking pragmatic knowledge, teachers or other educators should pay attention to the emphasis and input of pragmatic awareness and pragmatic knowledge. In order to avoid pragmatic failure, the third part proves some strategies. The experimental method proves that pragmatic teaching is helpful to the improvement of pragmatic competence. English is a common language in the world, so the importance of English pragmatics has been well known by learners; however, with the increase in non-native learners of Chinese, in the bilingual environment, language learners should also pay more and more attention to the understanding of Chinese culture.

평면형 능동위상 배열안테나 빔 패턴 보상에 관한 연구

전상미(Sang-Mi Chon),나형기(Hyung-ki Na),안창수(Chang-Soo Ahn),김선주(Seon-Joo Kim) 한국전자파학회 2014 한국전자파학회논문지 Vol.25 No.2

본 논문에서는 평면형 능동 위상 배열 안테나에서 일부 모듈의 고장이 발생할 경우, 발생되는 빔 패턴 왜곡을 여러 가지 경우로 비교하여 검토하고, 기존에 연구된 빔 패턴 보상 방법을 실제 안테나에 적용하여 빔 패턴 왜곡 개선 가능성을 분석하였다. 빔 패턴의 왜곡은 주로 부엽 수준의 증가로 나타나게 되는데, 부엽 수준이 기준치를 넘어서게 되면 고장 모듈을 제외한 나머지 모듈의 크기/위상값을 재조정하여 부엽을 낮출 수가 있으며, 본 논문에서는 이 방법을 실제 제작된 안테나에 적용하기 위한 방안 및 근접 전계 챔버에서 측정한 결과를 시뮬레이션 결과와 비교하여 나타내었다. 고장 모듈이 발생하는 경우는 무작위로 여러 곳에서 발생하는 경우와 여러 개의 배열을 포함하는 단위 모듈이 고장 날 경우로 나누어서, 시뮬레이션 결과와 측정 결과를 비교 분석하였다. 측정 결과는 시뮬레이션 결과와 유사한 경향을 나타내며, 고장 모듈이 발생할 경우 남아있는 정상 모듈의 크기/위상 조정을 통해서 부엽을 낮추기 위한 빔 패턴 보상이 가능함을 확인할 수 있다. This paper discusses about the beam pattern distortion caused by the failures of some antenna modules in the active array antenna and analyses the possibility of improvement through applying the beam pattern compensation method previously studied. The beam pattern distortion which is mostly represented as an increase of the sidelobe level, can be suppressed through re-synthesizing each module"s magnitude and phase. This method was applied to the prototype of active array antenna system, and the results of antenna pattern distortion and compensation were analyzed and measured in the Near Field Chamber. Array failures are generally divided into random TR module failures and TRU(TR Unit: combination of TR modules, Beam Computation module, Power supply module) failures. The results of beam pattern compensation were analyzed in each failure and compared to the results of the simulation. The beam pattern compensation results applied to the real active antenna array system showed the similar to the simulation results. Consequently, it was verified the beam pattern could be compensated with the magnitude and phase adjustment of other normal antenna modules.

PCB 공정상의 불량유형 분석

이수일(Soo-Il Lee),신성욱(Sung-Wook Shin),고대식(Dae-Sik Ko) 융복합지식학회 2014 융복합지식학회논문지 Vol.2 No.1

본 논문에서는 PCB 공정의 전반적인 과정과 발생 가능한 불량유형을 공정별로 나누어 분석하였다. 이를 위하여 에칭, 적층, 드릴, 도금, 솔더 마스킹으로 이어지는 PCB 공정을 조사 분석하고 각 공정상에서 발생하는 불량들의 유형을 분석하였다. 분석결과, 적층공정에서 동주름과 Delamination 불량이 1%이고, 솔더레지스트공정(S/R)에서 날인밀착, 잉크두께미달과 솔더레지스트 간섭불량이 3%이며, 도금공정에서 pit와 동크래치 불량이 2.5%로 나타난다. 그리고 드릴 공정에서 편심, 드릴피트마모와 홀 형성불량의 불량이 2%로 확인되었다. 이중에서도 전기적으로 동작에 가장 문제가 되는 불량은 도금공정 이고 불량률이 가장 높게 나타나는 것은 드릴 및 들뜸현상으로 확인되었다. This paper introduces the process of PCB manufacturing and possible failure patterns. For this, we studied the process of PCB manufacturing which includes etching, lamination, drilling, plating, solder masking, and analyzed possible failure patterns which are caused via each of those processes. According to the analysis result, the identified failure patterns were 1% failure on Wrinkle and Delamination in the stackup process, 3% failure on Stuck seal, Narrow ink and Solder resist invasion in the solder resist process(S/R), 2.5% failure on Pit and Cu Scratch in the plating process, and 2% failure on Eccentricity of Drill, Hole disappear and Hole shape failure in the drill process. Especially, the plating process caused the most electrical problem, and the drill, delamination processes have the highest failure rate.

강우패턴을 고려한 화강풍화토 사면의 침투 및 안정성 분석

이지성,김윤태,Lee. Ji Sung,Kim. Yun Tae 한국방재학회 2013 한국방재학회논문집 Vol.13 No.5

전 세계에서 우기 시 내린 유발강우로 인해 사면파괴가 발생하고, 이러한 사면파괴로 재산 및 인명에 상당한 피해를 주고 있다. 강우로 인한 사면파괴는 불포화 지반에서 모관흡수력의 감소로 인해 얕은 파괴형태로 발생한다. 본 연구에서는 실제 사면파괴 당시의 강우패턴을 산정하여 강우패턴이 화강풍화토 사면의 안정성에 미치는 영향을 분석하고자 하였다. 1999부터 2011년까지 사면파괴가 발생한 화강풍화토 지반을 대상으로 붕괴 유발 강우량을 분석하였다. 취합된 사면붕괴 사례는 총 106개이다. 국내 화강풍화토 사면에서 유발된 사면파괴와 유발강우에 대한 분석을 통해 2개의 사면파괴 유발 강우패턴을 도출하였다: 당일 강우량이 사면파괴에 큰 영향을 미치는 Strong major rainfall(SMR) 패턴과 파괴 하루 전 선행강우가 사면안정성에 영향을 미치는 Strong antecedent rainfall(SAR) 패턴. 또한 비교분석을 위하여 일정강우(Constant rainfall, CR) 패턴을 산정하여 불포화 사면의 침투 및 안정해석을 수행하였다. 해석결과, 사면의 안전율은 강우패턴, 강우강도 및 투수계수에 의존하는 것을 알 수 있다. Many slope disasters occur in many parts of the world during rainy season. Rainfall is one of the significant factors related to the landslides which cause a considerable damage to society. The rainfall-induced landslides in unsaturated slopes generally have shallow failure and are triggered by decrease in matric suction during rainfall. In this paper, effects of rainfall patterns on slope stability of the unsaturated weathered soil were investigated. Landslides inventory consisted of 106 landslides data from 1999 to 2011 was used to induce two rainfall patterns: strong major rainfall(SMR) pattern and strong antecedent rainfall(SAR) pattern. SMR pattern is a rainfall type in which the major rainfall of the landslide event day provides a key role on the landslide occurrence. SAR pattern is that the antecedent rainfall of the 1-antecedent day gives an important role on the landslide occurrence. Constant rainfall pattern was also used for comparison in numerical analysis. Combined seepage and stability analyses were performed to study the stability of slope subjected to various rainfall patterns. The results of numerical analysis indicated that variation of factor of safety of weathered granite slope depended on rainfall pattern, rainfall intensity and soil permeability.

Local Control May be the Key in Improving Treatment Outcomes of Esophageal Squamous Cell Carcinoma Undergoing Concurrent Chemoradiation

Kim, Hae Won,Kim, Jie-Hyun,Lee, Ik Jae,Kim, Jun Won,Lee, Yong Chan,Lee, Chang Geol,Park, Jae Jun,Youn, Young Hoon,Park, Hyojin S. Karger AG 2015 Digestion Vol.90 No.4

<P>Abstract</P><P><B><I>Background/Aim:</I></B> Little is known about the patterns of treatment failure following definitive chemoradiotherapy (CCRT), especially in esophageal squamous cell carcinoma (SCC). We evaluated definitive CCRT failure patterns and determined the predictive factors for treatment response in esophageal SCC. <B><I>Methods:</I></B> We evaluated 136 consecutive patients with esophageal SCC treated with definitive CCRT. We evaluated the factors associated with complete remission (CR) after CCRT and analyzed the pattern of treatment failure of recurred patients and incomplete remission patients. The failures were categorized as either within (locoregional failure) or outside the radiation field (out-field failure). <B><I>Results:</I></B> Fifty-seven patients achieved CR after CCRT. Consolidation chemotherapy was significantly associated with CR. Only 4 (7.0%) patients had CR after CCRT in patients with M1a node (Celiac or subclavian lymph nodes involvement by 6th AJCC). During follow-up, 74 patients (54.4%) experienced locoregional failure, 26 (19.1%) out-field failure, and 35 (25.7%) no failure. Esophageal obstruction prior to CCRT, residual tumor according to the first follow-up endoscopy, and poor follow-up computed tomography responses were significantly associated with locoregional failure. <B><I>Conclusion:</I></B> Approximately 70% of treatment failures were local failures. Future therapeutic strategies need to focus on improving local control to increase treatment outcomes of CCRT.</P><P>© 2014 S. Karger AG, Basel</P>

Breast Conservation Therapy Versus Mastectomy - Preliminary Results of Pattern of Failure and Survival Rate in Early Breast Cancer

김연실(Yeon-Sil Kim),윤세철(Sei-Chul Yoon),정수미(Su-Mi Chung),유미령(Mi-Ryeong Ryu),정상설(Sang-Sul Jung),최일봉(Ihl-Bohng Choi) 대한방사선종양학회 2004 Radiation Oncology Journal Vol.22 No.2

목 적: 조기 유방암에서 유방보존치료(유방보존수술+방사선치료) 혹은 유방전절제술로 치료했던 환자의 초 기 치료성적과 실패양상을 비교하고자 후향적으로 분석하였다. 대상 및 방법: 1989년 3월부터 1996년 8월까지 강남성모병원에서 AJCC병기 I, II로 치료를 받았던 유방암 환자를 대상으로 하였다. 88명은 유방전절제술을 시행하였고 85명은 유방보존술 후 방사선치료를 시행하였다. 방사선치료는 50 Gy 전 유방조사 후 원발부위에 10∼15 Gy 추가 조사하였다. 유방보존치료 환자의 34.1%, 유방전절제 환자의 45.5%에서 항암화학요법이 병용되었다. 양 치료군의 5년생존율과 5년무병생존율, 실패양상을 비교하였으며 치료실패와 연관된 위험인자를 Log-rank test를 이용하여 분석하였다. 중앙 추적기간은 63개월이었다. 결 과: 양 치료군 간에 5년생존율, 5년무병생존율의 유의한 차이(p>0.05)는 없었으며 국소재발 및 원격전이의 치료실패양상에도 차이가 없었다. 추적기간 중, 유방전절제군에서 11명(12.5%) 유방보존치료군에서 10명 (11.8%) 재발하였다. 초기 실패양상은 국소재발이 각각 6명, 5명이었고 원격전이가 각각 5명, 4명으로 차이가 없었다. 국소재발 단독의 경우 양 치료군에서 구제치료 후 대부분의 환자가 무병생존 (5/6 유방전절제술, 3/5 유방보존치료)하였다. 그러나 원격전이 환자의 경우 양 치료군 모두에서 방사선-항암화학요법의 구제치료에도 불구하고 대부분의 환자가 진행 혹은 사망하였으며 유방보존치료군의 1명의 환자만이 원격전이 후 구제치료에 성공하여 무병생존하였다. 양 치료군 간에 반대편유방암 발생률 및 다른 장기의 2차 원발암 발생률의 차이는 없었고 유방암으로 인한 사망률도 차이가 없었다. Log-rank 단변량분석에서 치료 실패와 관련된유의한 위험인자는 양 군 모두에서 N 병기, 액와 림프절 전이 숫자였으며 유방보존치료군에서는 수술절연침범유무가, 유방전절제군에서는 high nuclear grade가 치료실패와 관련된 위험인자였다(p<0.05). 결 론: 초기 분석결과 AJCC 병기 I, II 조기유방암에서 유방보존치료와 유방전절제술은 생존율뿐 아니라 치료 실패양상에도 차이가 없었으며 향후 이와 같은 결과를 확인하기 위한 장기간의 추적연구가 필요하다. Purpose: This retrospective study was conducted to compare early preliminary results of breast conservation therapy (BCT) with mastectomy in early breast cancer. Materials and Methods: We evaluated 171 women with AJCC stage I and II breast cancer who had been treated at Kangnam St. Mary’s Hospital from March 1989 to August 1996. Eighty-eight patients underwent mastectomy and 85 patients did conservative surgery with breast irradiation. In the BCT group, all patients received whole breast irradiation to a total dose of 45∼50 Gy/5∼6 wks, followed by a boost to the original tumor site at least 60 Gy. Chemotherapy was administered to 29 (34.1%) patients in BCT and 40 (45.5%) in mastectomy, with various sequencing of surgery and/or radiation. We compared survival rate, patterns of failure in each treatment group and the prognostic factors that had a significant effect on treatment failure. The median follow-up time was 63 months (19∼111 months). Log rank test was used to estimate the prognostic factors for treatment failure. Results: Overall survival, disease free survival, locoregional recurrence and distant metastasis rates were not significantly different between the two treatment groups. During the follow-up period, 11 patients (12.5%) in the mastectomy group and 10 patients (11.8%) in the BCT group were failed. Six local recurrences occurred after mastectomy and 5 after BCT. Five patients failed at distant site in mastectomy and 4 in BCT. Of the local recurrence cases, five of 6 mastectomy patients and 3 of 5 BCT patients were alive with no evidence of disease after salvage surgery and/or chemoirradiation. Our results indicated that the major influence on survival was distant metastasis. Unfortunately, control of distant metastasisis was not frequently achieved. Even with salvage systemic therapy or radiotherapy, most of distant metastasis patients died or had uncontrolled disease in both treatment groups: only one of 4 BCT patients and none of mastectomy patients were alive without disease. There was no apparent difference in the incidence rate of contralateral breast cancer and non-breast 2nd primary tumor between the two treatment groups. Univariate Log-rank test identified the N stage and the involved axillary LN number as distinct prognostic factors that were highly predictive of treatment failure in both treatment groups. Additionally, marginal status in BCT and histologic nuclear grade in the mastectomy group were risk factors for treatment failure (p<0.05). Conclusion: Although further careful follow-up is necessary to confirm the trends evident in this series, it would appear that patterns of failure and survival rate following conservative surgery and radiotherapy in early breast cancer are similar to those following mastectomy. The great majority of patients with local recurrence had an exellent salvage rate in both treatment groups. Therefore, these preliminary short term results support BCT as an equally effective management for early breast cancer as an alternative to mastectomy.

계층적 군집분석을 이용한 반도체 웨이퍼의 불량 및 불량 패턴 탐지

정주원,정윤서 한국통계학회 2022 응용통계연구 Vol.35 No.3

The semiconductor fabrication process is complex and time-consuming. There are sometimes errors in the process, which results in defective die on the wafer bin map (WBM). We can detect the faulty WBM by finding some patterns caused by dies. When one manually seeks the failure on WBM, it takes a long time due to the enormous number of WBMs. We suggest a two-step approach to discover the probable pattern on the WBMs in this paper. The first step is to separate the normal WBMs from the defective WBMs. We adapt a hierarchical clustering for de-noising, which nicely performs this work by wisely tuning the number of minimum points and the cutting height. Once declared as a faulty WBM, then it moves to the next step. In the second step, we classify the patterns among the defective WBMs. For this purpose, we extract features from the WBM. Then machine learning algorithm classifies the pattern. We use a real WBM data set (WM-811K) released by Taiwan semiconductor manufacturing company. 반도체는 제조 공정이 복잡하고 길어 결함이 발생될 때 빠른 탐지와 조치가 이뤄져야 결함으로 인한 손실을 최소화할 수 있다. 테스트 공정을 거쳐 구성된 웨이퍼 빈 맵(WBM)의 체계적인 패턴을 탐지하고 분류함으로써 문제의 원인을 유추할 수 있다. 이 작업은 수작업으로 이뤄지기 때문에 대량의 웨이퍼를 단 시간에 처리하는 데 한계가 있다. 본 논문은 웨이퍼 빈 맵의 정상 여부를 구분하기 위해 계층적 군집 분석을 활용한 새로운 결함 패턴 탐지 방법을 제시한다. 제시하는 방법은 여러 장점이 있다. 군집의 수를 알 필요가 없으며 군집분석의 조율 모수가 적고 직관적이다. 동일한 크기의 웨이퍼와 다이(die)에서는 동일한 조율 모수를 가지므로 대량의 웨이퍼도 빠르게 결함을 탐지할 수 있다. 소량의 결함 데이터만 있어도 그리고 데이터의 결함 비율을 가정하지 않더라도 기계학습 모형을 훈련할 수 있다. 제조 특성상 결함 데이터는 구하기 어렵고 결함의 비율이 수시로 바뀔 수 있기 때문에 필요하다. 또한 신규 패턴 발생시에도 안정적으로 탐지한다. 대만 반도체 기업에서 공개한 실제 웨이퍼 빈 맵 데이터(WM-811K)로 실험하였다. 계층적 군집 분석을 이용한 결함 패턴 탐지는 불량의 재현율이 96.31\%로 기존의 공간 필터(spatial filter)보다 우수함을 보여준다. 결함 분류는 혼합 유형에 장점이 있는 계층적 군집 분석을 그대로 사용한다. 직선형과 곡선형의 긁힘(scratch) 결함의 특징에 각각 주성분 분석의 고유값과 2차 다항식의 결정계수를 이용하고 랜덤 포레스트 분류기를 이용한다.