Hrant Khachatrian

Hrant Khachatrian


Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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17 June 2019 in Scientific Data
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Journal Article
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HHHrayr Harutyunyan
Hrayr Harutyunyan
HKHrant Khachatrian
Hrant Khachatrian
DKDavid C. Kale
David C. Kale
Greg Ver SteegGreg Ver Steeg
Greg Ver Steeg
AGAram Galstyan
Aram Galstyan
Health care is one of the most exciting frontiers in data mining and machine learning. Successful adoption of electronic health records (EHRs) created an explosion in digital clinical data available for analysis, but progress in machine learning for healthcare research has been difficult to measure because of the absence of publicly available benchmark data sets. To address this problem, we propose four clinical prediction benchmarks using data derived from the publicly available Medical Information Mart for Intensive Care (MIMIC-III) database. These tasks cover a range of clinical problems including modeling risk of mortality, forecasting length of stay, detecting physiologic decline, and phenotype classification. We propose strong linear and neural baselines for all four tasks and evaluate the effect of deep supervision, multitask training and data-specific architectural modifications on the performance of neural models.

21 August 2013 in Journal of Graph Theory
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PPPetros A. Petrosyan
Petros A. Petrosyan
HKHrant Khachatrian
Hrant Khachatrian
An edge‐coloring of a graph G with colors is called an interval t‐coloring if all colors are used, and the colors of edges incident to any vertex of G are distinct and form an interval of integers. In 1991, Erdős constructed a bipartite graph with 27 vertices and maximum degree 13 that has no interval coloring. Erdős's counterexample is the smallest (in a sense of maximum degree) known bipartite graph that is not interval colorable. On the other hand, in 1992, Hansen showed that all bipartite graphs with maximum degree at most 3 have an interval coloring. In this article, we give some methods for constructing of interval non‐edge‐colorable bipartite graphs. In particular, by these methods, we construct three bipartite graphs that have no interval coloring, contain 20, 19, 21 vertices and have maximum degree 11, 12, 13, respectively. This partially answers a question that arose in [T.R. Jensen, B. Toft, Graph coloring problems, Wiley Interscience Series in Discrete Mathematics and Optimization, 1995, p. 204]. We also consider similar problems for bipartite multigraphs.

1 January 2013 in Discussiones Mathematicae Graph Theory
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Journal Article
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HKHrant Khachatrian
Hrant Khachatrian
PPPetros A. Petrosyan
Petros A. Petrosyan
HTHovhannes G. Tananyan
Hovhannes G. Tananyan
Discussiones Mathematicae Graph Theory

1 March 2018 in Discrete Mathematics
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CCCarl Johan Casselgren
Carl Johan Casselgren
HKHrant Khachatrian
Hrant Khachatrian
PPPetros A. Petrosyan
Petros A. Petrosyan

1 September 2014 in Discrete Applied Mathematics
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Journal Article
Closed access
AGA. Grzesik
A. Grzesik
HKHrant Khachatrian
Hrant Khachatrian

8 May 2025 in Electronics
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Journal Article
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RMRafayel Mkrtchyan
Rafayel Mkrtchyan
EGEdvard Ghukasyan
Edvard Ghukasyan
KPKhoren Petrosyan
Khoren Petrosyan
HKHrant Khachatrian
Hrant Khachatrian
Theofanis RaptisTheofanis Raptis
Theofanis Raptis
Indoor pathloss prediction is a fundamental task in wireless network planning, yet it remains challenging due to environmental complexity and data scarcity. In this work, we propose a deep learning-based approach utilizing a vision transformer (ViT) architecture with DINO-v2 pretrained weights to model indoor radio propagation. Our method processes a floor map with additional features of the walls to generate indoor pathloss maps. We systematically evaluate the effects of architectural choices, data augmentation strategies, and feature engineering techniques. Our findings indicate that extensive augmentation significantly improves generalization, while feature engineering is crucial in low-data regimes. Through comprehensive experiments, we demonstrate the robustness of our model across different generalization scenarios.