diff --git a/Cargo.lock b/Cargo.lock
index 575c667..d9e61e8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -86,7 +86,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "cc"
-version = "1.0.59"
+version = "1.0.60"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -196,7 +196,7 @@ dependencies = [
 
 [[package]]
 name = "either"
-version = "1.6.0"
+version = "1.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -271,7 +271,7 @@ name = "itertools"
 version = "0.7.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "either 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "either 1.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -279,7 +279,7 @@ name = "itertools"
 version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "either 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "either 1.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -289,12 +289,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "kurobako"
-version = "0.2.5"
+version = "0.2.6"
 dependencies = [
  "chrono 0.4.15 (registry+https://github.com/rust-lang/crates.io-index)",
  "indicatif 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "kurobako_core 0.1.7",
- "kurobako_problems 0.1.9",
+ "kurobako_core 0.1.8",
+ "kurobako_problems 0.1.10",
  "kurobako_solvers 0.2.0",
  "nasbench 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "num 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -311,7 +311,7 @@ dependencies = [
 
 [[package]]
 name = "kurobako_core"
-version = "0.1.7"
+version = "0.1.8"
 dependencies = [
  "itertools 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -328,12 +328,13 @@ dependencies = [
 
 [[package]]
 name = "kurobako_problems"
-version = "0.1.9"
+version = "0.1.10"
 dependencies = [
  "hdf5file 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "kurobako_core 0.1.7",
+ "kurobako_core 0.1.8",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "nasbench 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "randomforest 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "randomforest 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.116 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.57 (registry+https://github.com/rust-lang/crates.io-index)",
  "structopt 0.3.17 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -344,7 +345,7 @@ dependencies = [
 name = "kurobako_solvers"
 version = "0.2.0"
 dependencies = [
- "kurobako_core 0.1.7",
+ "kurobako_core 0.1.8",
  "rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.116 (registry+https://github.com/rust-lang/crates.io-index)",
  "structopt 0.3.17 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -543,7 +544,7 @@ dependencies = [
  "proc-macro-error-attr 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc-macro2 1.0.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 1.0.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 1.0.41 (registry+https://github.com/rust-lang/crates.io-index)",
  "version_check 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -629,7 +630,7 @@ dependencies = [
 
 [[package]]
 name = "randomforest"
-version = "0.1.2"
+version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "byteorder 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -651,13 +652,13 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "autocfg 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-deque 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "either 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "rayon-core 1.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "either 1.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rayon-core 1.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "rayon-core"
-version = "1.8.0"
+version = "1.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "crossbeam-channel 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -700,7 +701,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "bstr 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
- "cc 1.0.59 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cc 1.0.60 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.77 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.12 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -740,7 +741,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro2 1.0.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 1.0.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 1.0.41 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -788,12 +789,12 @@ dependencies = [
  "proc-macro-error 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc-macro2 1.0.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 1.0.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 1.0.41 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "syn"
-version = "1.0.40"
+version = "1.0.41"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro2 1.0.21 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -854,7 +855,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro2 1.0.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 1.0.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 1.0.41 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -881,7 +882,7 @@ version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "quote 1.0.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 1.0.41 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -974,7 +975,7 @@ dependencies = [
 "checksum byte-tools 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e3b5ca7a04898ad4bcd41c90c5285445ff5b791899bb1b0abdd2a2aa791211d7"
 "checksum bytecodec 0.4.13 (registry+https://github.com/rust-lang/crates.io-index)" = "b16ea882cfbd9aa6e8f999fed22662f4c8c0853d1d231edec276e0e1f5a802e7"
 "checksum byteorder 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "08c48aae112d48ed9f069b33538ea9e3e90aa263cfa3d1c24309612b1f7472de"
-"checksum cc 1.0.59 (registry+https://github.com/rust-lang/crates.io-index)" = "66120af515773fb005778dc07c261bd201ec8ce50bd6e7144c927753fe013381"
+"checksum cc 1.0.60 (registry+https://github.com/rust-lang/crates.io-index)" = "ef611cc68ff783f18535d77ddd080185275713d852c4f5cbb6122c462a7a825c"
 "checksum cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 "checksum chrono 0.4.15 (registry+https://github.com/rust-lang/crates.io-index)" = "942f72db697d8767c22d46a598e01f2d3b475501ea43d0db4f16d90259182d0b"
 "checksum clap 2.33.3 (registry+https://github.com/rust-lang/crates.io-index)" = "37e58ac78573c40708d45522f0d80fa2f01cc4f9b4e2bf749807255454312002"
@@ -985,7 +986,7 @@ dependencies = [
 "checksum crossbeam-epoch 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)" = "058ed274caafc1f60c4997b5fc07bf7dc7cca454af7c6e81edffe5f33f70dace"
 "checksum crossbeam-utils 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c3c7c73a2d1e9fc0886a08b93e98eb643461230d5f1925e4036204d5f2e261a8"
 "checksum digest 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "f3d0c8c8752312f9713efd397ff63acb9f85585afbf179282e720e7704954dd5"
-"checksum either 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "cd56b59865bce947ac5958779cfa508f6c3b9497cc762b7e24a12d11ccde2c4f"
+"checksum either 1.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e78d4f1cc4ae33bbfc157ed5d5a5ef3bc29227303d595861deb238fcec4e9457"
 "checksum encode_unicode 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "a357d28ed41a50f9c765dbfe56cbc04a64e53e5fc58ba79fbc34c10ef3df831f"
 "checksum fake-simd 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e88a8acf291dafb59c2d96e8f59828f3838bb1a70398823ade51a84de6a6deed"
 "checksum generic-array 0.12.3 (registry+https://github.com/rust-lang/crates.io-index)" = "c68f0274ae0e023facc3c97b2e00f076be70e254bc851d972503b328db79b2ec"
@@ -1030,10 +1031,10 @@ dependencies = [
 "checksum rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
 "checksum rand_distr 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "96977acbdd3a6576fb1d27391900035bf3863d4a16422973a409b488cf29ffb2"
 "checksum rand_hc 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
-"checksum randomforest 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "476e4339b0819ed3c56a297c32e79c62f7c228b2dc8773930dbb3ad0b53fb2d0"
+"checksum randomforest 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "8346f8ef70970cdce426e7ad845502a80cf98ad7352c6c08079f55fe48646b8a"
 "checksum rawpointer 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ebac11a9d2e11f2af219b8b8d833b76b1ea0e054aa0e8d8e9e4cbde353bdf019"
 "checksum rayon 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "cfd016f0c045ad38b5251be2c9c0ab806917f82da4d36b2a327e5166adad9270"
-"checksum rayon-core 1.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "91739a34c4355b5434ce54c9086c5895604a9c278586d1f1aa95e04f66b525a0"
+"checksum rayon-core 1.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e8c4fec834fb6e6d2dd5eece3c7b432a52f0ba887cf40e595190c4107edc08bf"
 "checksum redox_syscall 0.1.57 (registry+https://github.com/rust-lang/crates.io-index)" = "41cc0f7e4d5d4544e8861606a285bb08d3e70712ccc7d2b84d7c0ccfaf4b05ce"
 "checksum regex 1.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "9c3780fcf44b193bc4d09f36d2a3c87b251da4a046c87795a0d35f4f927ad8e6"
 "checksum regex-syntax 0.6.18 (registry+https://github.com/rust-lang/crates.io-index)" = "26412eb97c6b088a6997e05f69403a802a92d520de2f8e63c2b65f9e0f47c4e8"
@@ -1049,7 +1050,7 @@ dependencies = [
 "checksum strsim 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
 "checksum structopt 0.3.17 (registry+https://github.com/rust-lang/crates.io-index)" = "6cc388d94ffabf39b5ed5fadddc40147cb21e605f53db6f8f36a625d27489ac5"
 "checksum structopt-derive 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)" = "5e2513111825077552a6751dfad9e11ce0fba07d7276a3943a037d7e93e64c5f"
-"checksum syn 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)" = "963f7d3cc59b59b9325165add223142bbf1df27655d07789f109896d353d8350"
+"checksum syn 1.0.41 (registry+https://github.com/rust-lang/crates.io-index)" = "6690e3e9f692504b941dc6c3b188fd28df054f7fb8469ab40680df52fdcc842b"
 "checksum tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6e24d9338a0a5be79593e2fa15a648add6138caa803e2d5bc782c371732ca9"
 "checksum terminal_size 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "9a14cd9f8c72704232f0bfc8455c0e861f0ad4eb60cc9ec8a170e231414c1e13"
 "checksum termios 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6f0fcee7b24a25675de40d5bb4de6e41b0df07bc9856295e7e2b3a3600c400c2"
diff --git a/Cargo.toml b/Cargo.toml
index e540420..dd84482 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "kurobako"
-version = "0.2.5"
+version = "0.2.6"
 authors = ["Takeru Ohta <phjgt308@gmail.com>"]
 edition = "2018"
 description = "A black-box optimization benchmarking framework"