• Journal of Gastric Cancer
• /
• v.18 no.4
• /
• pp.368-378
• /
• 2018

Purpose: Fibrinogen and platelets have been reported to play important roles in tumorigenesis and cancer progression. The aim of this research was to investigate the combination of functions of fibrinogen, platelets, and mean platelet volume (MPV) in predicting the survival of patients with gastric cancer (GC). Materials and Methods: A retrospective study was conducted with 1,946 patients with GC and 299 patients with benign gastric tumor to analyze their fibrinogen, platelet, and MPV levels, and other clinicopathological characteristics along with their prognoses. Several indicators were evaluated along with fibrinogen, platelets, and MPV and their prognostic abilities were assessed. Univariate and multivariate survival analyses were conducted to determine the independent risk factors for overall survival. Results: Increased levels of fibrinogen, platelets, and MPV were observed with the progress of the GC stages. Elevated fibrinogen, platelets, and the combined indicators, including fibrinogen*MPV (FM), platelet*fibrinogen*MPV (PFM), fibrinogen/MPV (FMR), platelet*fibrinogen (PF), platelet*fibrinogen/MPV (PFMR), platelet*MPV (PM), and platelet/MPV (PMR), foreboded poor prognosis. Meanwhile fibrinogen and FMR can be considered as independent risk factors for overall survival in patients with non-metastatic GC. But these indicators can hardly predict survival of patients in stage IV. Conclusions: Elevated fibrinogen, platelets, and MPV levels were in accordance with advanced stages, and fibrinogen, platelet, and MPV, in combination, can be used to predict survival of patients with non-metastatic GC. FMR was an independent prognostic factor for overall survival of patients with GC.

• Journal of the Korean Statistical Society
• /
• v.32 no.2
• /
• pp.163-174
• /
• 2003

We propose a test for independence of bivariate censored data under univariate censorship. To do this, we first introduce a process defined by the difference between bivariate survival function estimator proposed by Lin and Ying (1993) and the product of the product-limit estimators (Kaplan and Meier, 1958) for the marginal survival functions, and derive its asymptotic properties under the null hypothesis of independence. We propose a Cramer-von Mises-type test procedure based on the process . We conduct simulation studies to investigate the finite-sample performance of the proposed test and illustrate the proposed test with a real example.

• Journal of the Korean Statistical Society
• /
• v.28 no.4
• /
• pp.469-478
• /
• 1999

We propose a Kolmogorov-Smirnov-type test for independence of paired failure times in the presence of independent censoring times. This independent censoring mechanism is often assumed in case-control studies. To do this end, we first introduce a process defined as the difference between the bivariate survival function estimator proposed by Wang and Wells (1997) and the product of the product-limit estimators (Kaplan and Meier (1958)) for the marginal survival functions. Then, we derive its asymptotic properties under the null hypothesis of independence. Finally, we assess the performance of the proposed test by simulations, and illustrate the proposed methodology with a dataset for remission times of 21 pairs of leukemia patients taken from Oakes(1982).

• The Korean Journal of Applied Statistics
• /
• v.7 no.2
• /
• pp.53-77
• /
• 1994

In a certain stochastic process, Cox's regression model is used to analyze multistate survival data. From this model, the regression parameter vectors, survival functions, and the probability of being in response function are estimated based on multistate Cox's partial likelihood and nonparametric likelihood methods. The asymptotic properties of these estimators are described informally through the counting process approach. An example is given to likelihood the results in this paper.

• IMMUNE NETWORK
• /
• v.20 no.3
• /
• pp.20.1-20.15
• /
• 2020

Memory CD8+ T cells in the immune system are responsible for the removal of external Ags for a long period of time to protect against re-infection. Naïve to memory CD8+ T cell differentiation and memory CD8+ T cell maintenance require many different factors including local environmental factors. Thus, it has been suggested that the migration of memory CD8+ T cells into specific microenvironments alters their longevity and functions. In this review, we have summarized the subsets of memory CD8+ T cells based on their migratory capacities and described the niche hypothesis for their survival. In addition, the basic roles of CCR7 in conjunction with the migration of memory CD8+ T cells and recent understandings of their survival niches have been introduced. Finally, the applications of altering CCR7 signaling have been discussed.

• Proceedings of the Technology Innovation Conference
• /
• 1996.12a
• /
• pp.241-264
• /
• 1996

This article introduces the five functions of the national innovation system (NIS). As the national innovation system is a kind of social systems in the national level, the five generic functions of open system-production boundary spanning, maintenance, adaptation management functions-are applied to the NIS. The production function is the primary process, which produces innovative products and services of the NIS. The boundary spanning function is the function of procuring the input and disposing the innovation output or aiding in these process. Experienced R&D human resources, R&D funds, technology etc. belong to the input of the NIS. The maintenance function is responsible for the smooth operation and upkeep of the system in terms of various conditions. The adaptive function is to help the system change and adapt, scan the environment for problems, opportunities, and technological developments. It faces outward for the survival of the system from the long-term view. The management function carries out planning and controlling the overall activities for the other four functions in order to run the system. Finally it discuses implications for the diagnosis and the decision making process of S&T policy.

• Journal of the Korean Statistical Society
• /
• v.28 no.1
• /
• pp.35-44
• /
• 1999

We derive a new upper bound of convolution type for the median-unbiased estimators with respect to an arbitrary unimodal utility functions. We also obtain the necessary and sufficient condition for the attainability of the information bound. Applications to general MLR(Monotone Likelihood Ratio) model and censored survival data re discussed as examples.

• Molecules and Cells
• /
• v.41 no.7
• /
• pp.684-694
• /
• 2018

Upregulation of human telomerase reverse transcriptase (hTERT) expression is an important factor in the cellular survival and cancer. Although growing evidence suggests that hTERT inhibits cellular apoptosis by telomere-independent functions, the mechanisms involved are not fully understood. Here, we show that hTERT contains a BH3-like motif, a short peptide sequence found in BCL-2 family proteins, and interacts with anti-apoptotic BCL-2 family proteins MCL-1 and BCL-xL, suggesting a functional link between hTERT and the mitochondrial pathway of apoptosis. Additionally, we propose that hTERT can be categorized into the atypical BH3-only proteins that promote cellular survival, possibly due to the non-canonical interaction between hTERT and antiapoptotic proteins. Although the detailed mechanisms underlying the hTERT BH3-like motif functions and interactions between hTERT and BCL-2 family proteins have not been elucidated, this work proposes a possible connection between hTERT and BCL-2 family members and reconsiders the role of the BH3-like motif as an interaction motif.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.27 no.6
• /
• pp.737-743
• /
• 2024

Entering the 1990s, 80 to 90 % of aircraft losses occurred due to MANPADS(Man Portable Air Defense System) attacks, and during the Russian invasion of Ukraine, Ukraine used MANPADS, a type of infrared guided missile, to kill many aircraft. The importance of survival systems is increasing as aircraft are intercepted. In this paper, we present a test equipment development plan to verify that EWC, which acts as an MC of a survival system, responds optimally in real time without delay in a situation simulating an actual threat. The EWC test equipment presented in this paper not only includes functions such as interface verification and self-diagnosis, but also includes automatic EWC functional performance testing and operation scenario-based EWC logic verification functions to verify that the EWC responds optimally in real time in various threat cases.

• Communications for Statistical Applications and Methods
• /
• v.26 no.6
• /
• pp.623-633
• /
• 2019

This paper proposes two distance measures between two cumulative hazard functions that can be obtained by comparing their difference and ratio, respectively. Then we estimate the measures and present goodness of t test statistics. Since the proposed test statistics are expressed in terms of the cumulative hazard functions, we can easily give more weights on earlier (or later) departures in cumulative hazards if we like to place an emphasis on earlier (or later) departures. We also show that these test statistics present comparable performances with other well-known test statistics based on the empirical distribution function for an exponential null distribution. The proposed test statistic is an omnibus test which is applicable to other lots of distributions than an exponential distribution.