An Empirical Characteristic Function Approach to Selecting a Transformation to Normality

Yeo, In-Kwon,Johnson, Richard A.,Deng, XinWei The Korean Statistical Society 2014 Communications for statistical applications and me Vol.21 No.3

In this paper, we study the problem of transforming to normality. We propose to estimate the transformation parameter by minimizing a weighted squared distance between the empirical characteristic function of transformed data and the characteristic function of the normal distribution. Our approach also allows for other symmetric target characteristic functions. Asymptotics are established for a random sample selected from an unknown distribution. The proofs show that the weight function $t^{-2}$ needs to be modified to have thinner tails. We also propose the method to compute the influence function for M-equation taking the form of U-statistics. The influence function calculations and a small Monte Carlo simulation show that our estimates are less sensitive to a few outliers than the maximum likelihood estimates.

미국과 한국 임산업계의 인터넷 이용 실태 비교 연구

(Richard P. Vlosky),윤여창(Yeo Chang Youn) 한국산림과학회 2002 한국산림과학회지 Vol.91 No.2

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JAK-STAT signaling pathway mediates astrogliosis in brains of scrapie-infected mice

Na, Yeo-Jung,Jin, Jae-Kwang,Kim, Jae-Il,Choi, Eun-Kyoung,Carp, Richard I.,Kim, Yong-Sun Raven Press [etc.] 2007 Journal of neurochemistry Vol.103 No.2

<P>Abstract</P><P>Scrapie is characterized histologically, in part, by astrogliosis in brain and spinal cord. However, the mechanisms of astrogliosis in brain injury occurring during prion infection are not well understood. In this study, we investigated the expression levels and cellular localization of Janus kinase (JAK) -signal transducers and activators of transcription (STAT) signaling molecules and growth factors such as leukemia inhibitory factor (LIF) and ciliary neurotropic factor (CNTF) by western blot analysis and immunohistochemistry. We found that expression levels of LIF and CNTF were increased in scrapie-infected brains and phosphorylated (p)-JAK2, p-STAT1 (Ser727 and Tyr701), p-STAT3 (Tyr705), and glial fibrillary acidic protein were expressed strongly in scrapie-infected brains. Moreover, we found that p-STAT1 and p-STAT3 were found mainly in the nucleus in scrapie-infected brains. Immunohistochemically, p-STAT1 was colocalized with LIF and CNTF and p-JAK2 in many reactive astrocytes in scrapie-infected brains. In contrast, immunostaining for p-STAT3 was found in comparatively few astrocytes in limited regions; p-STAT3 staining merged with p-JAK2 in hippocampus sections of scrapie-infected brains. Taken together, our results suggest that activation of JAK2-STAT1 signaling pathway occurred in reactive astrocytes in hippocampus of scrapie-infected brains.</P>

Assessment of hydrophobic organic contaminant availability in sediments after sorbent amendment and its complete removal

Wu, Yanwen,Cho, Yeo-Myoung,Luthy, Richard G.,Kim, Kibeum,Jung, Jihyeun,Gala, William R.,Choi, Yongju Elsevier Applied Science Publishers 2017 Environmental pollution Vol.231 No.2

<P><B>Abstract</B></P> <P>Sorbents amended to sediments in situ for sequestration of hydrophobic organic contaminants (HOCs) may be swept away from the treated sites due to hydrodynamic forces applied to the sediment surface. The purpose of this study is to examine the possibility of recovery of HOC availability in sorbent-amended sediment after complete removal of the sorbent. Sediment contact with an easily separable model sorbent Tenax beads for 28 days in a slurry phase resulted in 74–98% reduction in polycyclic aromatic hydrocarbon and polychlorinated biphenyl availability compared to the untreated controls. HOC availability in the sorbent-treated sediment slightly increased by sorbent removal and after one month of mixing in a slurry phase because the slowly-desorbing HOC fraction was released and repartitioned back to the sediment, partially replenishing the rapidly-desorbing HOC fraction. However, HOC availability did not further increase during an extended mixing period of 12 months suggesting that the repartitioning process was not an infinite source. HOC availability after the 12-month post-treatment mixing for the sorbent-treated sediment was 53–97% lower than that of the untreated sediment because of the combined effect of HOC mass removal from sediment (with the sorbent) and incomplete recovery of available HOC fraction in the sorbent-treated sediment.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Sorbent-sediment contact substantially reduces HOC availability in sediment. </LI> <LI> HOC mass transfer to sorbent ranges 14–90% by 1-month slurry-phase contact. </LI> <LI> Sorbent winnowing causes slight rebound of HOC availability in sediment. </LI> <LI> HOC availability of treated sediment does not reach close to the initial value by sorbent winnowing. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Observation of heavy- and light-hole split direct bandgap photoluminescence from tensile-strained GeSn (0.03% Sn)

Harris, Thomas R.,Yeo, Yung Kee,Ryu, Mee-Yi,Beeler, Richard T.,Kouvetakis, John American Institute of Physics 2014 JOURNAL OF APPLIED PHYSICS - Vol.116 No.10

Electrical characterization studies of p-type Ge, Ge1−ySny, and Si0.09Ge0.882Sn0.028 grown on n-Si substrates

Harris, Thomas R.,Ryu, Mee-Yi,Yeo, Yung Kee,Beeler, Richard T.,Kouvetakis, John Elsevier 2014 Current Applied Physics Vol.14 No.1

The electrical properties of p-type Ge, Ge1-ySny, and Si0.09Ge0.882Sn0.028 samples grown on n-type Si substrates using ultra-high vacuum chemical vapor deposition have been investigated as a function of temperature. Degenerate parallel conducting layers were found in all Ge/Si, Ge1-ySny/Si, and Si0.09Ge0.882Sn0.028/Si samples, which are believed to be associated with dislocation defects at the interface produced by the lattice mismatch between the two materials. These degenerate conducting layers affect the electrical properties of all the thin epitaxial films. Additionally, temperature dependent Hall-effect measurements show that these materials exhibit a conductivity type change from p to n at around 370-435 K. The mobilities of these samples are generally lower than that of bulk Ge due to carrier scattering near the interface between the epitaxial layer and the Si substrate and also due to alloy scattering. Detailed behavior of temperature-dependent conductivity of these samples is also discussed. (C) 2013 Elsevier B.V. All rights reserved.

Effect of Occlusal Stabilization Appliance on Driving Distance in Golf

Tae-Hoon Kwon(권태훈),Sang-Wan Shin(신상완),Jae-Jun Ryu(류재준),Richard Sung-bok Lee(이성복),Su-Jin Ahn(안수진),Yeo-Jin Choi(최여진) 대한턱관절교합학회 2010 구강회복응용과학지 Vol.26 No.2

Survival outcome of women with synchronous cancers of endometrium and ovary: a 10 year retrospective cohort study

Yong Kuei Lim,Rama Padma,Lilian Foo,Yin Nin Chia,Philip Yam,John Chia,HS Khoo-Tan,Swee Peng Yap,Richard Yeo 대한부인종양학회 2011 Journal of Gynecologic Oncology Vol.22 No.4

Objective: Synchronous occurrence of endometrial and ovarian tumors is uncommon, and they affect less than 10% of women with endometrial or ovarian cancers. The aim of this study is to describe the epidemiological and clinical factors; and survival outcomes of women with these cancers. Methods: This is a retrospective cohort study in a large tertiary institution in Singapore. The sample consists of women with endometrial and epithelial ovarian cancers followed up over a period of 10 years from 2000 to 2009. The epidemiological and clinical factors include age at diagnosis, histology types, grade and stage of disease. Results: A total of 75 patients with synchronous ovarian and endometrial cancers were identified. However, only 46 patients met the inclusion criteria. The median follow-up was 74 months. The incidence rate for synchronous cancer is 8.7% of all epithelial ovarian cancers and 4.9% of all endometrial cancers diagnosed over this time frame. Mean age at diagnosis was 47.3 years old. The most common presenting symptom was abnormal uterine bleeding (36.9%) and 73.9% had endometrioid histology for both endometrial and ovarian cancers. The majority of the women (78%) presented were at early stages of 1 and 2. There were 6 (13.6%) cases of recurrence and the 5 year cumulative survival rate was at 84%. Conclusion: In our cohort, we found that majority of women afflicted with synchronous cancer of the endometrium and ovary were younger at age of diagnosis, had early stage of cancer and good survival. Objective: Synchronous occurrence of endometrial and ovarian tumors is uncommon, and they affect less than 10% of women with endometrial or ovarian cancers. The aim of this study is to describe the epidemiological and clinical factors; and survival outcomes of women with these cancers. Methods: This is a retrospective cohort study in a large tertiary institution in Singapore. The sample consists of women with endometrial and epithelial ovarian cancers followed up over a period of 10 years from 2000 to 2009. The epidemiological and clinical factors include age at diagnosis, histology types, grade and stage of disease. Results: A total of 75 patients with synchronous ovarian and endometrial cancers were identified. However, only 46 patients met the inclusion criteria. The median follow-up was 74 months. The incidence rate for synchronous cancer is 8.7% of all epithelial ovarian cancers and 4.9% of all endometrial cancers diagnosed over this time frame. Mean age at diagnosis was 47.3 years old. The most common presenting symptom was abnormal uterine bleeding (36.9%) and 73.9% had endometrioid histology for both endometrial and ovarian cancers. The majority of the women (78%) presented were at early stages of 1 and 2. There were 6 (13.6%) cases of recurrence and the 5 year cumulative survival rate was at 84%. Conclusion: In our cohort, we found that majority of women afflicted with synchronous cancer of the endometrium and ovary were younger at age of diagnosis, had early stage of cancer and good survival.