Broadcast Technology No.58, Autumn 2014 ● C NHK STRL 21

NHK’s Web service called “NEWSWEB EASY” (http://www.nhk.or.jp/news/easy/) provides news stories written in simplified Japanese text for non-native residents in Japan and children. Each item is a rewrite of a news script originally written in ordinary Japanese language and various hints are attached in order to enhance readers’ comprehension. STRL supports the production of the service through its research on natural language processing tech-nologies. We recently constructed a new production support system (Figure).

NEWSWEB EASY presents news in simple Japanese text, and its articles are written through a col-laboration between an experienced news writer who edits the original news script into simpler composi-tions and a Japanese language instructor (specializing in teaching Japanese language to non-Japanese

speakers) who paraphrases unfa-miliar expressions or complicated sentence structures to fit the target readers. For these rewriters’ assis-tance in replacing all the difficult words with more appropriate ones, our system color-codes every word in the manuscript they are writing to indicate the vocabu-lary type (e.g., biographical/geo-graphical names) and difficulty level. The system then tags each word in the finished rewrite with various information. After manu-ally correcting errors in automatic tagging, the simplified Japanese news items are published with the hints generated from the tags, such as pronunciations of Kanji words and plain explanations of difficult words.

The automatic tagging technol-ogy is based on machine learning, which acquires knowledge from manually corrected tags made in the daily production. Our new

technology has approximately 95% automatic tagging accuracy. This means only small manual error corrections are needed on the auto-matically generated tags. Since the system learns from manually cor-rected tags incrementally (stream learning), it increases its knowl-edge and accuracy day by day.

Our system has a number of functions, such as one to search for past rewrites, and it has proven to be useful in daily production. NEWSWEB EASY currently pub-lishes about five news items daily, and we are conducting various studies, including ones on how to assist rewriters in different ways, aimed at making it easier for the service to provide more simplified Japanese news items.

Natural Language Processing Technology to Support Simplified Japanese News Service “NEWSWEB EASY”

Tadashi Kumano, Human Interface Research Division

日本は大久保嘉人選手など

place namebasic wordperson nameperson namesemi-difficult wordbasic word

にっぽん

おおくぼよしとせんしゅ

「にほん」ともいい…

競技に出るために ..おもな例をあげて…

Word Type/difficulty Pronunciation Explanation

NEWSWEB EASY online page

Word tagging knowledge

Automatic tagging

Vocabulary type/difficulty color-coding

Difficulty level confirmation screen

Tag editor Errors are corrected manually

Incremental learning from corrected tags

Pronunciation

Explanation of difficult vocabularies

Color-coding geographical/biographical names

Checks manuscript currently being edited

Rewrite work Tag work

Original news script

ワールドカップ　日本は 0−0 でギリシャと引き分け20 日、サッカーのワールドカップで日本はギリシャと試合をしました。日本は 15 日の試合でコートジボワールに負けました。ギリシャにも負けると、決勝トーナメント (=上から 16番目までのチームが優勝を決めるために行う試合 ) に出ることができません。必ず勝ちたいと考えて、日本は大久保嘉人選手などを試合の最初から出しました。

Figure: NEWSWEB EASY production support using automatic tagging technology

Broadcast Technology No.58, Autumn 2014 ● C NHK STRL22

Bidirectional FPU for High-speed Program Materials File Transmission

Broadcasting stations are rap-idly switching to file-based systems, which manage video and audio footage on non-tape-based media such as hard disks. While video editing and playout systems have started incorporating file-based systems, the FPU systems, which transmit video and audio sig-nals from news-gathering and relay locations to broadcasting stations using microwaves, are not designed to transfer file data. This makes it necessary to decode video files into video signals, thereby making it harder to reduce the transmission time to less than the actual duration.

In addition to the uplink used to send video to a broadcasting station, a high-speed, lossless file-based ma-terial transmission system requires a downlink for returning control data for transmission rate control and retransmission requests to the news-gathering or relay location. To resolve this issue, STRL has devel-

oped a novel FPU that is capable of bidirectional communication.

This bidirectional FPU uses a time division duplex (TDD) scheme in which the uplink and downlink use the same frequency channel but at different times (Figure). This system can set the uplink/downlink data rate ratio by controlling uplink/downlink time ratio. Since the data rate of control data is much less than that of file data, assigning a higher data rate to the uplink enables high-speed transmissions in less than half the time of the actual video duration through the use of efficient dual-polarized 2×2 MIMO*1 transmission technology and 256-QAM*2 multi-level modulation.

The bidirectional FPU’s IP inter-face multiplexes signals to make it feasible to transmit real-time video signals, in addition to video files. Our prototype device enables return video signals from the studio to be transmitted to the news-gathering

or relay location and recorded video materials to be uploaded in the back-ground.

In the future, we will develop a means to select appropriate trans-mission data rates for individual propagation paths, with the goal of developing a more reliable bidirec-tional FPU system.

*1 Dual-polarized 2×2 MIMO: a transmis-sion technology based on spatial mul-tiplexing using multiple transmission/reception antennas over horizontally and vertically polarized waves.

*2 QAM: quadrature amplitude modula-tion

Fumiki Uzawa, Advanced Transmission Systems Research Division

Video material server

Video file reception

Video fileFile-based editing

Camera video Relay staff

Camera video

IP interface IP interface

UplinkNews-gathering/outside broadcasting Broadcasting stationDownlink Time

Studio

Polarization multiplexing

Studio video return

Video file transmission

Camera video transmission

Bidirectional communication

using TDD scheme

Bidirectional FPU baseband transceiver

Bidirectional FPU RF

front-end

Bidirectional FPU baseband transceiver

Bidirectional FPU RF

front-end

Studio video return

Studio video return

Video file transmission

Camera video transmission

Figure: Bidirectional FPU overview