Robust direction identification and variable selection in high dimensional general single-index models

Kangning Wang 한국통계학회 2015 Journal of the Korean Statistical Society Vol.44 No.4

Direction estimation and variable selection in a general class of models with single-index structure are considered. Under mild condition, we show simple linear quantile regression can offer a consistent and asymptotical normal estimate for the direction of index parameter vector in the presence of diverging number of predictors, and it does not need to estimate the link function, and without error distribution constraint. To do variable selection, we penalize the simple linear quantile regression by SCAD, and the oracle property is established. Simulation results and real data analysis confirm our method.

린위탕 한국에 오다, ‘동양ㆍ중국 지식’의 월경적 유통의 내면 -린위탕의 1968년 내한 연설을 중심으로-

Wang Kangning 국제한국문학문화학회 2019 사이 Vol.27 No.-

Based on the historical context of South Korea in the 1960s, this paper studies the two speeches delivered by Lin Yutang at the second IAUP (International Association of University President) conference and the Civil Hall in Seoul during his visit to Korea in 1968. Lin took different strategies according to the different characters of audiences in the two speeches. His speech at the IAUP conference especially emphasized the importance of Oriental (Chinese) thought / philosophy based on the harmony of cultures of the East and West. However, in his speech aimed at the Korean public, he no longer praised the superiority of the Oriental (Chinese) traditional culture, but pointed out its shortcomings, and proposed that the poor oriental developing countries which were still struggling with poverty should “hurry, hurry and hurry” to seize all the opportunities to achieve modernization. Such two “Oriental thought+modernization” speeches tailored for different groups of audiences were very satisfactory and timely for the Park Jeonghee regime, which was sprinting for the “modernization of the motherland” and “the road of national restoration” at that time. However, in the view of the Korean public, Lin Yutang, who was still the face of “East-West Bridge” and “Oriental Wisdom” at the IAUP conference, unexpectedly advocated modernization strongly when standing in front of them. This would inevitably lead to confusion in the audience’s understanding. Although it is essentially different on the context and connotation between Lin’s traditional Oriental (Chinese) thought and modernization and the official discourse of the Park Jeonghee government, both are likely to be accepted by the public as the same voice in the end, due to the latter’s strong power in Korea. At the same time, regardless of the actual content of the speech, Lin Yutang could won the enthusiastic applause of the Korean public with the world fame he had always enjoyed. 본고에서는 린위탕이 1968년에 직접 방한하면서 세계대학총장회의와 시민회관에서 가진 연설을 한국의 역사적 현장 맥락과 연결 지어 살펴보았다. 린위탕은 청중의 상이한 성격에 따라 세계대학총장회의에서는 ‘동서 융합’의 기반 위에 동양사상의 중요성을 거론했고, 한국 국민을 대상으로 한 강연에서는 동양(중국)의 문화전통을 찬양하는 대신에 그 약점을 지적하고 동양 후진국이 나아가야 할 방안을 제시하며 가난에서 스스로 기회를 찾아 “빨리 빨리 빨리” 근대화를 실현할 것을 호소했다. 이처럼 “동양사상+근대화”라는 ‘맞춤형’ 연설은 당시 “조국의 근대화”, “민족중흥의 길”을 향해 한창 전력질주하고 있었던 박정희 정권에게는 매우 “만족스러운” 발언이었다. 그러나 세계대학총장회의에서 여전히 ‘동서의 교량’, ‘동양의 지혜’와 같은 익숙한 이미지를 보여주었던 린위탕이 정작 한국의 일반대중 앞에서는 뜻밖에도 근대화를 채찍질하기만 한 것은 듣는 이들에게 혼선을 유발할 수밖에 없었다. 비록 린위탕이 강조한 중국ㆍ동양의 전통사상과 근대화의 배후 맥락과 내포가 박정희 체제의 그것과 질적으로 달랐음에도 불구하고, 후자의 강력한 공세로 인해 대중에게는 양자가 결국은 같은 목소리로 받아들여졌을 공산이 크다. 그러나 그 실제 강연 내용이 어떠했든 간에 린위탕은 그가 기왕에 향유해 왔던 세계적인 명망과 커다란 아우라로 인해 한국 청중에게 대대적인 환영을 받을 수 있었다.

Walsh-average based variable selection for varying coefficient models

Kangning Wang,Lu Lin 한국통계학회 2015 Journal of the Korean Statistical Society Vol.44 No.1

A shrinkage-type variable selection procedure for varying coefficient models is routinelyestablished in the least-squares (LS) framework. Although the LS method has favorableproperties for a large class of error distributions, it will break down if the error varianceis infinite and is adversely affected by outliers and heavy-tail distributions. To overcomethese issues, we propose a robust shrinkage method termed regularized Walsh-average(RWA) that can construct robust nonparametric variable selection and robust coefficientestimation simultaneously. Theoretical analysis reveals RWA works beautifully, includingconsistency in variable selection and oracle property in estimation, even when error varianceis infinite. More important property is that when error variance is finite, comparedwith the LS based estimators, the asymptotic relative efficiency of the new estimator is atleast 0.8896, a relatively high level. Furthermore, a robust BIC-type criterion, which canidentify the true model consistently, is suggested for shrinkage parameter selection. Numericalstudies also confirm our theories.

Variable selection in robust semiparametric modeling for longitudinal data

Kangning Wang,Lu Lin 한국통계학회 2014 Journal of the Korean Statistical Society Vol.43 No.2

This paper considers robust variable selection in semiparametric modeling for longitudinaldata with an unspecified dependence structure. First, by basis spline approximationand using a general formulation to treat mean, median, quantile and robust mean regressionsin one setting, we propose a weighted M-type regression estimator, which achievesrobustness against outliers in both the response and covariates directions, and can accommodateheterogeneity, and the asymptotic properties are also established. Furthermore, apenalized weighted M-type estimator is proposed, which can do estimation and select relevantnonparametric and parametric components simultaneously, and robustly. Withoutany specification of error distribution and intra-subject dependence structure, the variableselection method works beautifully, including consistency in variable selection and oracleproperty in estimation. Simulation studies also confirm our method and theories.

타이완의 「두 페인트공」과 한국의 <칠수와 만수>의 상호성 연구

왕캉닝 ( Wang Kangning ) 한국문학연구학회 2016 현대문학의 연구 Vol.0 No.60

1986년 당시 한국의 대표적인 진보적 극단이었던 ‘연우(演友)`는 <칠수와 만수>라는 연극을 공연하여 큰 센세이션을 불러일으켰다. 그리고 불과 2년 뒤인 1988년에 이 작품은 곧 한국의 신예 감독 박광수에 의해 동명 영화 <칠수와 만수>로 각색되어 다시금 세간에 제 모습을 내밀었다. 이 영화는 당시 베를린 영화제 등 유수의 세계 영화제 10곳에서 호평을 받아 1989년에 일본까지 수출되어 도쿄테아트르극장에서 개봉되기도 했다. 그러나 흥미로운 것은 한국의 희곡과 영화 분야에서 모두 큰 성공을 거두었던 <칠수와 만수>는 순수 창작물이 아니라 기실 타이완 작가 황춘밍의 단편소설 「두 페인트공」을 ‘번안`한 작품이었다는 점이다. 본고에서는 타이완의 원작 소설 「두 페인트공」과 한국의 희곡·영화 <칠수와 만수>를 비교했다. 세 작품은 대체로 기본적인 풀롯이 동일하되 인물의 형상화에 있어서는 적지 않은 차이점을 보인다. 희곡과 영화<칠수와 만수>는 소설의 아리와 원숭이보다 훨씬 더 능동적이고 반항적인 인물로 그려졌다. 또한 세 텍스트는 동일하게 변두리 인물의 비극, 또는 개인과 사회 간의 의사소통의 부재(불능)를 강조하지만 타이완과 한국의 시대 배경 차이와 더불어 저자(감독) 각각의 성향 차이로 인해 서로 상이한 지향점에 착안하고 있다. 특히 이는 세 작품이 등장인물의 투신장면을 각각 다르게 처리한 데서 현저하게 드러난다. Korean representative progressive theater company, Yeon-woo, debuted a play called Chil-su and Man-su in 1986, and it was a huge sensation. Just 2 years later in 1988, this work was adapted into a movie of the same title by Korean rookie director, Park Kwang su. This movie was well received at 10 distinguished film festivals, including the Berlin Film Festival. And in 1989, it opened in Japan, premiering at the Tokyo Gejiko. However, what is interesting is that Chil-su and Man-su, which was hugely successful in Korea, is not a purely original work. It was in fact adapted from a Taiwanese writer, Huang Chunming`s short story named Two Painters(1971). In this study, I compared Huang Chunming`s original work Two Painters and the Korean play and movie Chil-su and Man-su. Although these three works` basic overall plots are similar, we see many differences with regards to the characters` imagery. Chil-su and Man-su from both the play and the movie are, compared to the novel`s A-Li and Hou-zi, painted as much more active and rebellious characters. In addition, the three texts commonly emphasize marginal man`s tragedy, as well as the absence of individual and communal communication; however, with Taiwan and Korean difference in background period as well as through each of the writers` or director`s difference in propensity, the three texts are aiming in different directions. This is especially evident in how each of the works handled the last jump scene remarkably differently.

욕망·전유·균열, 1960~70년대 출판·독서계 ‘린위탕 열풍’의 이면 : The Importance of Living을 중심으로

왕캉닝(Wang Kangning) 구보학회 2020 구보학보 Vol.0 No.26

린위탕은 1960~70년대의 한국 출판계에서 상당한 규모의 센세이션을 불러일으켰다. 이 가운데 특히 수필 작품은 다른 장르에 비해 위세를 떨쳤다. 특히 The Importance of Living 한 작품에 대한 일변도의 현상이 두드러지게 나타났다. The Importance of Living은 출판계, 교육계, 국가권력에 의해 대대적으로 정전화되었으며 “동양의 지혜”, “인생의 지침서”로 널리 받아들여졌다. 이러한 양상은 당시 ‘민족주의’ 담론의 부상과 출판계의 인생론이나 에세이류의 유행과도 밀접한 관계가 있다. The Importance of Living에서 담겨 있는 지식은 한국 사회에서 매우 빠른 속도로 광범위하게 유통되고 흡수되었다. 이 시기의 신문 지면에는 린위탕의 다양한 아포리즘이 등장했다. 여기서 ‘린위탕’의 앎은 단순히 제한적인 ‘중국 문화 지식’이라는 범주 안에서만 수용되지 않고, 보편적인 상식과 교양으로 받아들여졌다. ‘교양 대중화’·‘국민개독(國民皆讀)’의 시대적 분위기에서 린위탕은 수준 높은 지식과 지적 앎이 극도로 필요했던 일반 대중 사이를 매개해 주었다. 그가 The Importance of Living을 통해 전달한 한적철학은 여성 주체와 직장인에게 적극적으로 받아들여지면서 불온성을 유발하기도 했다. 그리고 린위탕의 현세적 행복관은 당시 한국사회의 집단심성과 맞닿아 있다. 그러나 한국 사회의 보편적 멘탈리티는 행복, 쾌락, 여가생활에 대한 추구라는 점에서는 린위탕과 공통지대를 형성했지만, 궁극적으로는 그의 한적철학의 정신적 내핵과 거리가 멀다. Lin Yutang created a considerable sensation in the Korean reading and publishing market in the 1960s and 1970s. Looking at the overall publication of Lin Yu-tang literature, the publication of essay works clearly overwhelmed that of other genres such as novels. This is especially true of The Importance of Living, which became a canon with the strong efforts of the publishing industry, education and state power, and was widely accepted as “wisdom of the East” and “guidelines for life”. The active acceptance of The Importance of Living is closely related to the rise of the “nationalism” discourse and the popularity of essays on life in the publishing market at the time. Along with the publishing boom of The Importance of Living, the knowledge contained in this work was widely disseminated and absorbed in Korean society at a very rapid pace. During this period, a wide spectrum of Lin Yutang’s aphorisms appeared in the newspapers. It is important to note that the knowledge from “Lin Yutang” was not simply accepted within the specific category of “Chinese knowledge”, but was treated as universal common sense and culture(bildung). In the era of “national culture(bildung)” or “national reading”, Lin Yutang became a powerful medium for connecting specialized knowledge with the general public. The sense of leisure that he conveyed through The Importance of Living was positively accepted by female subjects and workers, also showing a dissonance with the national discourse. And Lin Yutang’s view of being more concerned with the present, the physical and personal happiness than with the future, the soul and society conformed to the collective psychology of Korean society. However, the Korean society formed a consensus with Lin Yutang at the starting point of the pursuit of happiness, enjoyment and leisure life, but it was completely at odds with the spiritual core of his “philosophy of xianshi(leisure)”.

Robust adaptive model selection and estimation for partial linear varying coefficient models in rank regression

Xiaofei Sun,Kangning Wang,Lu Lin 한국통계학회 2018 Journal of the Korean Statistical Society Vol.47 No.1

Partial linear varying coefficient models are often used in real data analysis for a good balance between flexibility and parsimony. In this paper, we propose a robust adaptive model selection method based on the rank regression, which can do simultaneous coefficient estimation and three types of selections, i.e., varying and constant effects selection, relevant variable selection. The new method has superiority in robustness and efficiency by inheriting the advantage of the rank regression approach. Furthermore, consistency in the three types of selections and oracle property in estimation are established as well. Simulation studies also confirm our method.

Effects of Glucagon-like Peptide-2 on Morphology, Proliferation and Enzyme Activity of Intestinal Enterocyte Cells of Weaned Piglets In vitro

Jia, Gang,Jiang, RongChuan,Wang, KangNing Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.8

This study was conducted according to the single-factor design principle to investigate in vitro the effects of different glucagon-like peptide-2 (GLP-2) concentrations (0, $1{\times}10^{-11}$, $1{\times}10^{-10}$, $1{\times}10^{-9}$, $1{\times}10^{-8}$ and $1{\times}10^{-7}$ mol/L) on the morphology, proliferation and enzyme activity of intestinal enterocyte cells of 28-d-old weaned piglets. These cells were primary cultured in 4 pieces of 24-well cell culture plate. After having been grown for 48 h in culture media with hGLP-2, the ileal enterocyte cells of 28-d-old weaned piglets exhibited the typical characteristics of simple columnar epithelium. Compared with the control groups, the quantities of treated cells significantly increased (p<0.05) and their corresponding absorption values in 540 nm (MTT OD) also significantly increased (p<0.01). Likewise, lactic acid concentration, total protein content and protein retention significantly increased (p<0.05). $Na^{+}$, $K^{+}$-ATP enzyme activity was more active (p<0.05), although the activity of alkaline phosphatase, lactic acid dehydrogenase and creatine phosphokinase in culture media significantly decreased (p<0.01). To summarize, the results indicated that GLP-2 in vitro is capable of promoting the proliferation of intestinal enterocyte cells of 28-d weaned piglets, restraining their apoptosis and maintaining the integrity of their morphology.

Effects of Glucagon-like Peptide-2 on Morphology, Proliferation and Enzyme Activity of Intestinal Enterocyte Cells of Weaned Piglets In vitro

Gang Jia,RongChuan Jiang,KangNing Wang 아세아·태평양축산학회 2009 Animal Bioscience Vol.22 No.8

This study was conducted according to the single-factor design principle to investigate in vitro the effects of different glucagon-like peptide-2 (GLP-2) concentrations (0, 1×10-11, 1×10-10, 1×10-9, 1×10-8 and 1×10-7 mol/L) on the morphology, proliferation and enzyme activity of intestinal enterocyte cells of 28-d-old weaned piglets. These cells were primary cultured in 4 pieces of 24-well cell culture plate. After having been grown for 48 h in culture media with hGLP-2, the ileal enterocyte cells of 28-d-old weaned piglets exhibited the typical characteristics of simple columnar epithelium. Compared with the control groups, the quantities of treated cells significantly increased (p<0.05) and their corresponding absorption values in 540 nm (MTT OD) also significantly increased (p<0.01). Likewise, lactic acid concentration, total protein content and protein retention significantly increased (p<0.05). Na+, K+-ATP enzyme activity was more active (p<0.05), although the activity of alkaline phosphatase, lactic acid dehydrogenase and creatine phosphokinase in culture media significantly decreased (p<0.01). To summarize, the results indicated that GLP-2 in vitro is capable of promoting the proliferation of intestinal enterocyte cells of 28-d weaned piglets, restraining their apoptosis and maintaining the integrity of their morphology.

The application of modified isochronal well test in a low-permeability condensate gas field

Zhaojing Zhou,Xiuwei Wang,Xue Miao,Kangning Qian,Lijian Li,Peng Xu,Xiuqin Lu 한국자원공학회 2019 Geosystem engineering Vol.22 No.6

The modified isochronal well test is a deliverability test method suitable for gas wells in low-permeability gas reservoirs. Generally, the absolute open flow of gas wells is determined by modified isochronal well test, thereby establishing a reasonable working system for gas wells. It is also possible to obtain gas layer physical parameters, gas reservoir engineering parameters, heterogeneity, boundary characteristics, etc. In this paper, the actual test data of a condensate gas field are applied. By modified isochronal well test analysis, not only the deliverability equation of the gas well is obtained, but also the absolute open flow is determined. At the same time, the formation parameters such as reservoir permeability and skin factor are obtained and the acidification effect is evaluated.