diff --git a/lib/mihari/analyzers/base.rb b/lib/mihari/analyzers/base.rb
index 577daae6c..4d41a218f 100644
--- a/lib/mihari/analyzers/base.rb
+++ b/lib/mihari/analyzers/base.rb
@@ -63,12 +63,10 @@ def normalized_artifacts
         artifacts.compact.sort.map do |artifact|
           # No need to set data_type manually
           # It is set automatically in #initialize
-          artifact = artifact.is_a?(Models::Artifact) ? artifact : Models::Artifact.new(data: artifact)
-
-          artifact.source = self.class.key
-          artifact.query = query
-
-          artifact
+          (artifact.is_a?(Models::Artifact) ? artifact : Models::Artifact.new(data: artifact)).tap do |normalized|
+            normalized.source = self.class.key
+            normalized.query = query
+          end
         end.select(&:valid?).uniq(&:data)
       end
 
@@ -118,18 +116,9 @@ class << self
         #
         # @return [Mihari::Analyzers::Base]
         #
-        def from_query(params)
-          copied = params.deep_dup
-
-          # convert params into arguments for initialization
-          query = copied[:query]
-
-          # delete analyzer and query
-          %i[analyzer query].each { |key| copied.delete key }
-
-          copied[:options] = copied[:options] || nil
-
-          new(query, **copied)
+        def from_params(params)
+          query = params.delete(:query)
+          new(query, **params)
         end
 
         def inherited(child)
diff --git a/lib/mihari/emitters/slack.rb b/lib/mihari/emitters/slack.rb
index 823a62f04..4cec8d741 100644
--- a/lib/mihari/emitters/slack.rb
+++ b/lib/mihari/emitters/slack.rb
@@ -176,21 +176,11 @@ def target
       # @return [::Slack::Notifier]
       #
       def notifier
-        @notifier ||= [].tap do |out|
-          out << if timeout.nil?
-            ::Slack::Notifier.new(
-              webhook_url,
-              channel: channel, username: username
-            )
-          else
-            ::Slack::Notifier.new(
-              webhook_url,
-              channel: channel,
-              username: username,
-              http_options: { timeout: timeout }
-            )
-          end
-        end.first
+        @notifier ||= lambda do
+          return ::Slack::Notifier.new(webhook_url, channel: channel, username: username) if timeout.nil?
+
+          ::Slack::Notifier.new(webhook_url, channel: channel, username: username, http_options: { timeout: timeout })
+        end.call
       end
 
       #
diff --git a/lib/mihari/enrichers/whois.rb b/lib/mihari/enrichers/whois.rb
index 2b90be35f..1f9350217 100644
--- a/lib/mihari/enrichers/whois.rb
+++ b/lib/mihari/enrichers/whois.rb
@@ -53,13 +53,11 @@ def memoized_call(domain)
       # @return [::Whois::Client]
       #
       def whois
-        @whois ||= [].tap do |out|
-          out << if timeout.nil?
-            ::Whois::Client.new
-          else
-            ::Whois::Client.new(timeout: timeout)
-          end
-        end.last
+        @whois ||= lambda do
+          return ::Whois::Client.new if timeout.nil?
+
+          ::Whois::Client.new(timeout: timeout)
+        end.call
       end
 
       #
diff --git a/lib/mihari/rule.rb b/lib/mihari/rule.rb
index fbf2a3857..cafb5c2c2 100644
--- a/lib/mihari/rule.rb
+++ b/lib/mihari/rule.rb
@@ -2,6 +2,7 @@
 
 module Mihari
   class Rule < Service
+    include Concerns::FalsePositiveNormalizable
     include Concerns::FalsePositiveValidatable
 
     # @return [Hash]
@@ -136,8 +137,7 @@ def artifacts
       analyzer_results.flat_map do |result|
         artifacts = result.value!
         artifacts.map do |artifact|
-          artifact.rule_id = id
-          artifact
+          artifact.tap { |tapped| tapped.rule_id = id }
         end
       end
     end
@@ -188,9 +188,7 @@ def enriched_artifacts
     def bulk_emit
       return [] if enriched_artifacts.empty?
 
-      Parallel.map(emitters) do |emitter|
-        emitter.result(enriched_artifacts).value_or nil
-      end.compact
+      Parallel.map(emitters) { |emitter| emitter.result(enriched_artifacts).value_or nil }.compact
     end
 
     #
@@ -315,12 +313,12 @@ def get_analyzer_class(key)
     # @return [Array<Mihari::Analyzers::Base>]
     #
     def analyzers
-      @analyzers ||= queries.map do |params|
-        analyzer_name = params[:analyzer]
-        klass = get_analyzer_class(analyzer_name)
-        analyzer = klass.from_query(params)
-        analyzer.validate_configuration!
-        analyzer
+      @analyzers ||= queries.deep_dup.map do |params|
+        name = params.delete(:analyzer)
+        klass = get_analyzer_class(name)
+        klass.from_params(params).tap do |analyzer|
+          analyzer.validate_configuration!
+        end
       end
     end
 
@@ -356,16 +354,14 @@ def get_emitter_class(key)
     # @return [Array<Mihari::Emitters::Base>]
     #
     def emitters
-      @emitters ||= data[:emitters].map(&:deep_dup).map do |params|
-        name = params[:emitter]
-        options = params[:options]
-
-        %i[emitter options].each { |key| params.delete key }
+      @emitters ||= data[:emitters].deep_dup.map do |params|
+        name = params.delete(:emitter)
+        options = params.delete(:options)
 
         klass = get_emitter_class(name)
-        emitter = klass.new(rule: self, options: options, **params)
-        emitter.validate_configuration!
-        emitter
+        klass.new(rule: self, options: options, **params).tap do |emitter|
+          emitter.validate_configuration!
+        end
       end
     end
 
@@ -386,11 +382,9 @@ def get_enricher_class(key)
     # @return [Array<Mihari::Enrichers::Base>] enrichers
     #
     def enrichers
-      @enrichers ||= data[:enrichers].map(&:deep_dup).map do |params|
-        name = params[:enricher]
-        options = params[:options]
-
-        %i[enricher options].each { |key| params.delete key }
+      @enrichers ||= data[:enrichers].deep_dup.map do |params|
+        name = params.delete(:enricher)
+        options = params.delete(:options)
 
         klass = get_enricher_class(name)
         klass.new(options: options, **params)
diff --git a/lib/mihari/services/proxies.rb b/lib/mihari/services/proxies.rb
index 6856cb8db..e61c405b0 100644
--- a/lib/mihari/services/proxies.rb
+++ b/lib/mihari/services/proxies.rb
@@ -79,10 +79,10 @@ def source
       # @return [Mihari::Rule]
       #
       def rule
-        @rule ||= [].tap do |out|
+        @rule ||= lambda do
           data = Mihari::Models::Rule.find(rule_id).data
-          out << Rule.new(**data)
-        end.first
+          Rule.new(**data)
+        end.call
       end
     end
   end
diff --git a/lib/mihari/web/endpoints/artifacts.rb b/lib/mihari/web/endpoints/artifacts.rb
index 67369153a..690962442 100644
--- a/lib/mihari/web/endpoints/artifacts.rb
+++ b/lib/mihari/web/endpoints/artifacts.rb
@@ -74,7 +74,7 @@ class Artifacts < Grape::API
               end
             end.to_result
 
-            message = queued ? "ID:#{id}'s enrichment has been queued" : "ID:#{id}'s enrichment has been succeeded"
+            message = queued ? "ID:#{id}'s enrichment is queued" : "ID:#{id}'s enrichment is successful"
             return present({ message: message, queued: queued }, with: Entities::QueueMessage) if result.success?
 
             case result.failure
diff --git a/lib/mihari/web/endpoints/rules.rb b/lib/mihari/web/endpoints/rules.rb
index 655550f67..fc13f00c3 100644
--- a/lib/mihari/web/endpoints/rules.rb
+++ b/lib/mihari/web/endpoints/rules.rb
@@ -94,7 +94,7 @@ def call(yaml, overwrite: true)
               end
             end.to_result
 
-            message = queued ? "ID:#{id}'s search has been queued" : "ID:#{id}'s search has been succeed"
+            message = queued ? "ID:#{id}'s search is queued" : "ID:#{id}'s search is successful"
             return present({ message: message, queued: queued }, with: Entities::QueueMessage) if result.success?
 
             case result.failure